20-F/A

As filed with the Securities and Exchange Commission on March 20, 2018

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 20-F/A

Amendment No. 1

☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934

OR

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2017

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

OR

☐ SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Commission file number 1-15170

GlaxoSmithKline plc

(Exact name of Registrant as specified in its charter)

England

(Jurisdiction of incorporation or organization)

980 Great West Road, Brentford, Middlesex TW8 9GS England

(Address of principal executive offices)

Victoria Whyte

Company Secretary

GlaxoSmithKline plc

980 Great West Road

Brentford, TW8 9GS

England

+44 20 8047 5000

company.secretary@gsk.com

(Name, Telephone, E-mail and/or Facsimile number and Address of Company Contact Person)

Securities registered or to be registered pursuant to Section 12(b) of the Act:

Title of Each Class	Name of Each Exchange On Which  Registered
American Depositary Shares, each representing 2 Ordinary Shares, Par value 25 pence	New York Stock Exchange
5.650% Notes due 2018	New York Stock Exchange
2.850% Notes due 2022	New York Stock Exchange
2.800% Notes due 2023	New York Stock Exchange
5.375% Notes due 2034	London Stock Exchange
6.375% Notes due 2038	New York Stock Exchange
4.200% Notes due 2043	New York Stock Exchange

Securities registered or to be registered pursuant to Section 12(g) of the Act:

None

(Title of class)

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act:

None

(Title of class)

Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.

Ordinary Shares of Par value 25 pence each 5,372,553,820

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

☒  Yes    ☐  No

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

☐  Yes    ☒  No

Note – Checking the box above will not relieve any registrant required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 from their obligations under those Sections.

Indicate by check mark whether the registrant (1) has filed all reports to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

☒  Yes    ☐  No

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

☒  Yes    ☐  No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer” and “large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer  ☒                Accelerated filer  ☐                Non-accelerated filer  ☐                Emerging growth company  ☐

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards† provided pursuant to Section 13(a) of the Exchange Act.  ☐

† The term “new or revised financial accounting standard” refers to any update issued by the Financial Accounting Standards Board to its Accounting Standards Codification after April 5, 2012.

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

U.S. GAAP  ☐ International Financial Reporting Standards as issued by the International Accounting Standards Board  ☒ Other  ☐

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.

Item 17  ☐    Item 18  ☐

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

☐  Yes    ☒  No

Explanatory Note

GlaxoSmithKline plc (“GSK”) is filing this Amendment No. 1 (the “Form 20-F/A”) to its Annual Report on Form 20-F for the year ended December 31, 2017 (the “Form 20-F”), which was filed with the Securities and Exchange Commission on March 16, 2018, to submit the Interactive Data File (as defined in Rule 11 of Regulation S-T) with respect to the audited consolidated financial statements of GSK and its consolidated subsidiaries for that fiscal year as an exhibit to the Form 20-F pursuant to paragraph 101 under “Instructions as to Exhibits” of Form 20-F in accordance with Rule 405 of Regulation S-T. Exhibit 101 was omitted from the Form 20-F in accordance with the 30-day grace period provided under Rule 405(a)(2)(ii) of Regulation S-T.

Except as set forth above, this Form 20-F/A does not modify or update any of the disclosures in the Form 20-F. This Form 20-F/A speaks as of the time of filing of the Form 20-F, does not reflect events that may have occurred subsequent to such filing, and does not modify or update in any way disclosures made in the Form 20-F.

Item 19 Exhibits

101.INS*	XBRL Instance Document
101.SCH*	XBRL Taxonomy Extension Schema Linkbase Document
101. CAL*	XBRL Taxonomy Extension Calculation Linkbase Document
101. DEF*	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB*	XBRL Taxonomy Extension Label Linkbase Document
101.PRE*	XBRL Taxonomy Extension Presentation Linkbase Document

* In accordance with Rule 402 of Regulation S-T, the information in these exhibits shall not be deemed to be “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liability of that section, and shall not be incorporated by reference into any registration statement or other document filed under the Securities Act, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Signature

The registrant hereby certifies that it meets all of the requirements for filing on Form 20-F and that it has duly caused and authorized the undersigned to sign this Amendment No.1 to the Annual Report on Form 20-F on its behalf.

	GlaxoSmithKline plc
March 20, 2018	By:	/s/ Simon Dingemans
		Simon Dingemans
		Chief Financial Officer

XML

Document and Entity Information	12 Months Ended
	Dec. 31, 2017 shares
Document - Document and Entity Information [Abstract]
Document Type	20-F/A
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	FY
Trading Symbol	GSK
Entity Registrant Name	GLAXOSMITHKLINE PLC
Entity Central Index Key	0001131399
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	5,372,553,820

XML

Consolidated income statement - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Profit or loss [abstract]
Turnover	£ 30,186	£ 27,889	£ 23,923
Cost of sales	(10,342)	(9,290)	(8,853)
Gross profit	19,844	18,599	15,070
Selling, general and administration	(9,672)	(9,366)	(9,232)
Research and development	(4,476)	(3,628)	(3,560)
Royalty income	356	398	329
Other operating income/(expense)	(1,965)	(3,405)	7,715
Operating profit	4,087	2,598	10,322
Finance income	65	72	104
Finance expense	(734)	(736)	(757)
Profit on disposal of interest in associates	94		843
Share of after tax profits of associates and joint ventures	13	5	14
Profit before taxation	3,525	1,939	10,526
Taxation	(1,356)	(877)	(2,154)
Profit after taxation for the year	2,169	1,062	8,372
Profit/(loss) attributable to non-controlling interests	637	150	(50)
Profit attributable to shareholders	1,532	912	8,422
Profit after taxation for the year	£ 2,169	£ 1,062	£ 8,372
Basic earnings per share (pence)	£ 0.314	£ 0.188	£ 1.743
Diluted earnings per share (pence)	£ 0.310	£ 0.186	£ 1.723

XML

Consolidated statement of comprehensive income - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of comprehensive income [abstract]
Profit after taxation for the year	£ 2,169	£ 1,062	£ 8,372
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges	462	646	(618)
Reclassification of exchange on liquidation or disposal of overseas subsidiaries	109
Fair value movements on available-for-saleinvestments	(14)	251	416
Deferred tax on fair value movements on available-for-saleinvestments	47		(91)
Reclassification of fair value movements on available-for-saleinvestments	(42)	(245)	(346)
Deferred tax reversed on reclassification of available-for-saleinvestments	(18)	51	36
Fair value movements on cash flow hedges	(10)	2	2
Deferred tax on fair value movements on cash flow hedges		2
Reclassification of cash flow hedges to income statement		1	2
Share of other comprehensive expense of associates and joint ventures			(77)
Items that may be subsequently reclassified to income statement	534	708	(676)
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests	(149)	603	8
Remeasurement gains/(losses) on defined benefit plans	549	(475)	261
Tax on remeasurement of defined benefit plans	(221)	126	(80)
Items that will not be reclassified to income statement	179	254	189
Other comprehensive income/(expense) for the year	713	962	(487)
Total comprehensive income/(expense) for the year	2,882	2,024	7,885
Total comprehensive income for the year attributable to:
Shareholders	2,394	1,271	7,927
Non-controlling interests	488	753	(42)
Total comprehensive income/(expense) for the year	£ 2,882	£ 2,024	£ 7,885

XML

Consolidated balance sheet - GBP (£)	Dec. 31, 2017	Dec. 31, 2016
Non-currentassets
Property, plant and equipment	£ 10,860,000,000	£ 10,808,000,000
Goodwill	5,734,000,000	5,965,000,000
Other intangible assets	17,562,000,000	18,776,000,000
Investments in associates and joint ventures	183,000,000	263,000,000
Other investments	918,000,000	985,000,000
Deferred tax assets	3,796,000,000	4,374,000,000
Derivative financial instruments	8,000,000
Other non-current assets	1,413,000,000	1,199,000,000
Total non-current assets	40,474,000,000	42,370,000,000
Current assets
Inventories	5,557,000,000	5,102,000,000
Current tax recoverable	258,000,000	226,000,000
Trade and other receivables	6,000,000,000	6,026,000,000
Derivative financial instruments	68,000,000	156,000,000
Liquid investments	78,000,000	89,000,000
Cash and cash equivalents	3,833,000,000	4,897,000,000
Assets held for sale	113,000,000	215,000,000
Total current assets	15,907,000,000	16,711,000,000
Total assets	56,381,000,000	59,081,000,000
Current liabilities
Short-term borrowings	(2,825,000,000)	(4,129,000,000)
Contingent consideration liabilities	(1,076,000,000)	(561,000,000)
Trade and other payables	(20,970,000,000)	(11,964,000,000)
Derivative financial instruments	(74,000,000)	(194,000,000)
Current tax payable	(995,000,000)	(1,305,000,000)
Short-term provisions	(629,000,000)	(848,000,000)
Total current liabilities	(26,569,000,000)	(19,001,000,000)
Non-current liabilities
Long-term borrowings	(14,264,000,000)	(14,661,000,000)
Corporation tax payable	(411,000,000)	0
Deferred tax liabilities	(1,396,000,000)	(1,934,000,000)
Pensions and other post-employment benefits	(3,539,000,000)	(4,090,000,000)
Other provisions	(636,000,000)	(652,000,000)
Contingent consideration liabilities	(5,096,000,000)	(5,335,000,000)
Other non-current liabilities	(981,000,000)	(8,445,000,000)
Total non-current liabilities	(26,323,000,000)	(35,117,000,000)
Total liabilities	(52,892,000,000)	(54,118,000,000)
Net assets	3,489,000,000	4,963,000,000
Equity
Share capital	1,343,000,000	1,342,000,000
Share premium account	3,019,000,000	2,954,000,000
Retained earnings	(6,477,000,000)	(5,392,000,000)
Other reserves	2,047,000,000	2,220,000,000
Shareholders' equity	(68,000,000)	1,124,000,000
Non-controlling interests	3,557,000,000	3,839,000,000
Total equity	£ 3,489,000,000	£ 4,963,000,000

XML

Consolidated statement of changes in equity - GBP (£) £ in Millions	Total	Share capital [member]	Share premium [member]	Retained earnings [member]	Other reserves [member]	Total [member]	Non- controlling interests [member]
Equity at beginning of period at Dec. 31, 2014	£ 4,936	£ 1,339	£ 2,759	£ (2,074)	£ 2,239	£ 4,263	£ 673
Profit after taxation for the year	8,372			8,422		8,422	(50)
Other comprehensive (expense)/income for the year	(487)			(520)	25	(495)	8
Total comprehensive income for the year	7,885			7,902	25	7,927	(42)
Distributions to non-controlling interests	(237)						(237)
Dividends to shareholders	(3,874)			(3,874)		(3,874)
Gains on transfer of net assets into Consumer Healthcare Joint Venture	2,891			2,891		2,891
Consumer Healthcare Joint Venture put option	(6,204)			(6,204)		(6,204)
Changes in non-controllinginterests	3,370						3,370
Loss on transfer of equity investment to investment in associate	(229)			(229)		(229)
Ordinary Shares issued	73	1	72			73
Ordinary Shares acquired by ESOP Trusts	(99)				(99)	(99)
Write-down of shares held by ESOP Trusts				(175)	175
Share-based incentive plans	356			356		356
Tax on share-based incentive plans	10			10		10
Equity at end of period at Dec. 31, 2015	8,878	1,340	2,831	(1,397)	2,340	5,114	3,764
Profit after taxation for the year	1,062			912		912	150
Other comprehensive (expense)/income for the year	962			284	75	359	603
Total comprehensive income for the year	2,024			1,196	75	1,271	753
Distributions to non-controlling interests	(534)						(534)
Dividends to shareholders	(4,850)			(4,850)		(4,850)
Recognition of liabilities with non-controlling interests	(2,172)			(2,013)		(2,013)	(159)
De-recognition of liabilities with non-controlling interests	1,244			1,244		1,244
Changes in non-controllinginterests	32			17		17	15
Ordinary Shares issued	89	2	87			89
Ordinary Shares acquired by ESOP Trusts	(74)		36	466	(576)	(74)
Write-down of shares held by ESOP Trusts				(381)	381
Share-based incentive plans	319			319		319
Tax on share-based incentive plans	7			7		7
Equity at end of period at Dec. 31, 2016	4,963	1,342	2,954	(5,392)	2,220	1,124	3,839
Profit after taxation for the year	2,169			1,532		1,532	637
Other comprehensive (expense)/income for the year	713			899	(37)	862	(149)
Total comprehensive income for the year	2,882			2,431	(37)	2,394	488
Distributions to non-controlling interests	(789)						(789)
Contribution from non-controlling interests	21						21
Dividends to shareholders	(3,906)			(3,906)		(3,906)
Changes in non-controllinginterests	(2)						(2)
Ordinary Shares issued	56	1	55			56
Ordinary Shares acquired by ESOP Trusts	(65)		10	581	(656)	(65)
Write-down of shares held by ESOP Trusts				(520)	520
Share-based incentive plans	333			333		333
Tax on share-based incentive plans	(4)			(4)		(4)
Equity at end of period at Dec. 31, 2017	£ 3,489	£ 1,343	£ 3,019	£ (6,477)	£ 2,047	£ (68)	£ 3,557

XML

Consolidated cash flow statement - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flow from operating activities
Profit after taxation for the year	£ 2,169	£ 1,062	£ 8,372
Adjustments reconciling profit after tax to operating cash flows	6,089	7,044	(3,741)
Cash generated from operations	8,258	8,106	4,631
Taxation paid	(1,340)	(1,609)	(2,062)
Net cash inflow from operating activities	6,918	6,497	2,569
Cash flow from investing activities
Purchase of property, plant and equipment	(1,545)	(1,543)	(1,380)
Proceeds from sale of property, plant and equipment	281	98	72
Purchase of intangible assets	(657)	(809)	(521)
Proceeds from sale of intangible assets	48	283	236
Purchase of equity investments	(80)	(96)	(82)
Proceeds from sale of equity investments	64	683	357
Contingent consideration paid	(91)	(73)	(338)
Purchase of businesses, net of cash acquired		17	(3,203)
Disposal of businesses	282	72	10,246
Investments in associates and joint ventures	(15)	(11)	(16)
Proceeds from disposal of subsidiary and interest in associate	196		564
Decrease/(increase) in liquid investments	4		(2)
Interest received	64	68	99
Dividends from associates, joint ventures and equity investments	6	42	5
Net cash (outflow)/inflow from investing activities	(1,443)	(1,269)	6,037
Cash flow from financing activities
Shares acquired by ESOP Trusts	(65)	(74)	(99)
Issue of share capital	56	89	73
Purchase of non-controllinginterests	(29)
Increase in long-term loans	2,233
(Repayment of)/Increase in short-term loans	(3,200)	148	(2,412)
Net repayment of obligations under finance leases	(23)	(18)	(25)
Interest paid	(781)	(732)	(762)
Dividends paid to shareholders	(3,906)	(4,850)	(3,874)
Distributions to non-controlling interests	(779)	(534)	(237)
Contributions from non-controlling interests	21
Other financing cash flows	93	(421)	233
Net cash outflow from financing activities	(6,380)	(6,392)	(7,103)
(Decrease)/increase in cash and bank overdrafts	(905)	(1,164)	1,503
Cash and bank overdrafts at beginning of year	4,605	5,486	4,028
Exchange adjustments	(100)	283	(45)
(Decrease)/increase in cash and bank overdrafts	(905)	(1,164)	1,503
Cash and bank overdrafts at end of year	3,600	4,605	5,486
Cash and bank overdrafts at end of year comprise:
Cash and cash equivalents	3,833	4,897	5,830
Overdrafts	(233)	(292)	(344)
Cash and bank overdrafts at end of year	£ 3,600	£ 4,605	£ 5,486

XML

Presentation of the financial statements

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Presentation of the financial statements

1. Presentation of the financial statements

Description of business

GSK is a major global healthcare group which is engaged in the creation and discovery, development, manufacture and marketing of pharmaceutical products, vaccines, over-the-counter (OTC) medicines and health-related consumer products. GSK’s principal pharmaceutical products include medicines in the following therapeutic areas: respiratory, HIV, immuno-inflammation, anti-virals, central nervous system, cardiovascular and urogenital, metabolic, anti-bacterials, dermatology and rare diseases.

Compliance with applicable law and IFRS

The financial statements have been prepared in accordance with the Companies Act 2006, Article 4 of the IAS Regulation and International Financial Reporting Standards (IFRS) and related interpretations, as adopted by the European Union.

The financial statements are also in compliance with IFRS as issued by the International Accounting Standards Board.

Composition of financial statements

The consolidated financial statements are drawn up in Sterling, the functional currency of GlaxoSmithKline plc, and in accordance with IFRS accounting presentation. The financial statements comprise:

• Consolidated income statement

• Consolidated statement of comprehensive income

• Consolidated balance sheet

• Consolidated statement of changes in equity

• Consolidated cash flow statement

• Notes to the financial statements.

Composition of the Group

A list of the subsidiaries and associates which, in the opinion of the Directors, principally affected the amount of profit or net assets of the Group is given in Note 44, ‘Principal Group companies’.

Accounting principles and policies

The financial statements have been prepared using the historical cost convention modified by the revaluation of certain items, as stated in the accounting policies, and on a going concern basis.

The financial statements have been prepared in accordance with the Group’s accounting policies approved by the Board and described in Note 2, ‘Accounting principles and policies’. Information on the application of these accounting policies, including areas of estimation and judgement is given in Note 3, ‘Key accounting judgements and estimates’.

The preparation of the financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Implementation of new accounting standards and interpretations

An agenda decision by the IFRS Interpretations Committee in September 2017 clarified that charges for interest on tax should be reported within finance expense and certain penalties on tax settlements should be reported within administrative expenses. Previously GSK had reported these charges within the overall tax charge in the income statement or other comprehensive income, as appropriate.

GSK has adopted the revised basis of reporting in 2017 and, as a result of a number of settlements during the year, has recorded credits for interest on tax for 2017 of £24 million in finance expense. There were no material charges for penalties on settlements during 2017 that required adjustment.

Accrued interest payable on tax at 31 December 2017 was £52 million, and this is included within trade and other payables on the Group balance sheet. The impact on prior years was not material and so prior year amounts have not been restated.

Financial period

These financial statements cover the financial year from 1 January to 31 December 2017, with comparative figures for the financial years from 1 January to 31 December 2016 and, where appropriate, from 1 January to 31 December 2015.

Parent company financial statements

The financial statements of the parent company, GlaxoSmithKline plc, have been prepared in accordance with UK GAAP and with UK accounting presentation. The company balance sheet is presented on page 239 and the accounting policies are given on page 240.

XML

Accounting principles and policies

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Accounting principles and policies

2. Accounting principles and policies

Consolidation

The consolidated financial statements include:

• the assets and liabilities, and the results and cash flows, of the company and its subsidiaries, including ESOP Trusts

• the Group’s share of the results and net assets of associates and joint ventures

• the Group’s share of assets, liabilities, revenue and expenses of joint operations.

The financial statements of entities consolidated are made up to 31 December each year.

Entities over which the Group has the power to direct the relevant activities so as to affect the returns to the Group, generally through control over the financial and operating policies, are accounted for as subsidiaries.

Where the Group has the ability to exercise joint control over, and rights to the net assets of, entities, the entities are accounted for as joint ventures. Where the Group has the ability to exercise joint control over an arrangement, but has rights to specified assets and obligations for specified liabilities of the arrangement, the arrangement is accounted for as a joint operation. Where the Group has the ability to exercise significant influence over entities, they are accounted for as associates. The results and assets and liabilities of associates and joint ventures are incorporated into the consolidated financial statements using the equity method of accounting. The Group’s rights to assets, liabilities, revenue and expenses of joint operations are included in the consolidated financial statements in accordance with those rights and obligations.

Interests acquired in entities are consolidated from the date the Group acquires control and interests sold are de-consolidated from the date control ceases.

Transactions and balances between subsidiaries are eliminated and no profit before tax is taken on sales between subsidiaries until the products are sold to customers outside the Group. The relevant proportion of profits on transactions with joint ventures, joint operations and associates is also deferred until the products are sold to third parties. Transactions with non-controlling interests are recorded directly in equity. Deferred tax relief on unrealised intra-Group profit is accounted for only to the extent that it is considered recoverable.

Business combinations

Business combinations are accounted for using the acquisition accounting method. Identifiable assets, liabilities and contingent liabilities acquired are measured at fair value at acquisition date. The consideration transferred is measured at fair value and includes the fair value of any contingent consideration. Where the consideration transferred, together with the non-controlling interest, exceeds the fair value of the net assets, liabilities and contingent liabilities acquired, the excess is recorded as goodwill. The costs of acquisition are charged to the income statement in the period in which they are incurred.

Goodwill is capitalised as a separate item in the case of subsidiaries and as part of the cost of investment in the case of joint ventures and associates. Goodwill is denominated in the currency of the operation acquired.

Where the cost of acquisition is below the fair value of the net assets acquired, the difference is recognised directly in the income statement.

Where not all of the equity of a subsidiary is acquired the non-controlling interest is recognised either at fair value or at the non-controlling interest’s share of the net assets of the subsidiary, on a case-by-case basis. Changes in the Group’s ownership percentage of subsidiaries are accounted for within equity.

Foreign currency translation

Foreign currency transactions are booked in the functional currency of the Group company at the exchange rate ruling on the date of transaction. Foreign currency monetary assets and liabilities are retranslated into the functional currency at rates of exchange ruling at the balance sheet date. Exchange differences are included in the income statement.

On consolidation, assets and liabilities, including related goodwill, of overseas subsidiaries, associates and joint ventures, are translated into Sterling at rates of exchange ruling at the balance sheet date. The results and cash flows of overseas subsidiaries, associates and joint ventures are translated into Sterling using average rates of exchange.

Exchange adjustments arising when the opening net assets and the profits for the year retained by overseas subsidiaries, associates and joint ventures are translated into Sterling, less exchange differences arising on related foreign currency borrowings which hedge the Group’s net investment in these operations, are taken to a separate component of equity.

When translating into Sterling the assets, liabilities, results and cash flows of overseas subsidiaries, associates and joint ventures which are reported in currencies of hyper-inflationary economies, adjustments are made where material to reflect current price levels. Any loss on net monetary assets is charged to the consolidated income statement.

Revenue

Revenue is recognised in the income statement when goods or services are supplied or made available to external customers against orders received, title and risk of loss is passed to the customer, reliable estimates can be made of relevant deductions and all relevant obligations have been fulfilled, such that the earnings process is regarded as being complete.

Turnover represents net invoice value after the deduction of discounts and allowances given and accruals for estimated future rebates and returns. The methodology and assumptions used to estimate rebates and returns are monitored and adjusted regularly in the light of contractual and legal obligations, historical trends, past experience and projected market conditions. Market conditions are evaluated using wholesaler and other third-party analyses, market research data and internally generated information. Value added tax and other sales taxes are excluded from revenue.

Where the Group co-promotes a product and the counterparty records the sale, the Group records its share of revenue as co-promotion income within turnover. The nature of co-promotion activities is such that the Group records no costs of sales. Pharmaceutical turnover includes co-promotion revenue of £16 million (2016 – £9 million; 2015 – £14 million). In addition, initial or event-based milestone income (excluding royalty income) arising on development or marketing collaborations of the Group’s compounds or products with other parties is recognised in turnover. No such income is included in turnover for all the periods presented.

Royalty income is recognised on an accruals basis in accordance with the terms of the relevant licensing agreements.

Expenditure

Expenditure is recognised in respect of goods and services received when supplied in accordance with contractual terms. Provision is made when an obligation exists for a future liability in respect of a past event and where the amount of the obligation can be reliably estimated. Manufacturing start-up costs between validation and the achievement of normal production are expensed as incurred. Advertising and promotion expenditure is charged to the income statement as incurred. Shipment costs on inter-company transfers are charged to cost of sales; distribution costs on sales to customers are included in selling, general and administrative expenditure.

Restructuring costs are recognised and provided for, where appropriate, in respect of the direct expenditure of a business reorganisation where the plans are sufficiently detailed and well advanced, and where appropriate communication to those affected has been undertaken.

Research and development

Research and development expenditure is charged to the income statement in the period in which it is incurred. Development expenditure is capitalised when the criteria for recognising an asset are met, usually when a regulatory filing has been made in a major market and approval is considered highly probable. Property, plant and equipment used for research and development is capitalised and depreciated in accordance with the Group’s policy.

Environmental expenditure

Environmental expenditure related to existing conditions resulting from past or current operations and from which no current or future benefit is discernible is charged to the income statement. The Group recognises its liability on a site-by-site basis when it can be reliably estimated. This liability includes the Group’s portion of the total costs and also a portion of other potentially responsible parties’ costs when it is probable that they will not be able to satisfy their respective shares of the clean-up obligation. Recoveries of reimbursements are recorded as assets when virtually certain.

Legal and other disputes

Provision is made for the anticipated settlement costs of legal or other disputes against the Group where an outflow of resources is considered probable and a reliable estimate can be made of the likely outcome. In addition, provision is made for legal or other expenses arising from claims received or other disputes. In respect of product liability claims related to certain products, there is sufficient history of claims made and settlements to enable management to make a reliable estimate of the provision required to cover unasserted claims. In certain cases, an incurred but not reported (IBNR) actuarial technique is used to determine this estimate.

The Group may become involved in legal proceedings, in respect of which it is not possible to make a reliable estimate of the expected financial effect, if any, that could result from ultimate resolution of the proceedings. In these cases, appropriate disclosure about such cases would be included but no provision would be made. Costs associated with claims made by the Group against third parties are charged to the income statement as they are incurred.

Pensions and other post-employment benefits

The costs of providing pensions under defined benefit schemes are calculated using the projected unit credit method and spread over the period during which benefit is expected to be derived from the employees’ services, consistent with the advice of qualified actuaries. Pension obligations are measured as the present value of estimated future cash flows discounted at rates reflecting the yields of high quality corporate bonds. Pension scheme assets are measured at fair value at the balance sheet date.

The costs of other post-employment liabilities are calculated in a similar way to defined benefit pension schemes and spread over the period during which benefit is expected to be derived from the employees’ services, in accordance with the advice of qualified actuaries.

Actuarial gains and losses and the effect of changes in actuarial assumptions, are recognised in the statement of comprehensive income in the year in which they arise.

The Group’s contributions to defined contribution plans are charged to the income statement as incurred.

Employee share plans

Incentives in the form of shares are provided to employees under share option and share award schemes.

The fair values of these options and awards are calculated at their grant dates using a Black-Scholes option pricing model and charged to the income statement over the relevant vesting periods.

The Group provides finance to ESOP Trusts to purchase company shares to meet the obligation to provide shares when employees exercise their options or awards. Costs of running the ESOP Trusts are charged to the income statement. Shares held by the ESOP Trusts are deducted from other reserves. A transfer is made between other reserves and retained earnings over the vesting periods of the related share options or awards to reflect the ultimate proceeds receivable from employees on exercise.

Property, plant and equipment

Property, plant and equipment (PP&E) is stated at the cost of purchase or construction, less provisions for depreciation and impairment. Financing costs are capitalised within the cost of qualifying assets in construction.

Depreciation is calculated to write off the cost less residual value of PP&E, excluding freehold land, using the straight-line basis over the expected useful life. Residual values and lives are reviewed, and where appropriate adjusted annually. The normal expected useful lives of the major categories of PP&E are:

Freehold buildings	20 to 50 years
Leasehold land and buildings	Lease term or 20 to 50 years
Plant and machinery	10 to 20 years
Equipment and vehicles	3 to 10 years

On disposal of PP&E, the cost and related accumulated depreciation and impairments are removed from the financial statements and the net amount, less any proceeds, is taken to the income statement.

Leases

Leasing agreements which transfer to the Group substantially all the benefits and risks of ownership of an asset are treated as finance leases, as if the asset had been purchased outright. The assets are included in PP&E or computer software and the capital elements of the leasing commitments are shown as obligations under finance leases. Assets held under finance leases are depreciated on a basis consistent with similar owned assets or the lease term, if shorter. The interest element of the lease rental is included in the income statement. All other leases are operating leases and the rental costs are charged to the income statement on a straight-line basis over the lease term.

Goodwill

Goodwill is stated at cost less impairments. Goodwill is deemed to have an indefinite useful life and is tested for impairment at least annually.

Where the fair value of the interest acquired in an entity’s assets, liabilities and contingent liabilities exceeds the consideration paid, this excess is recognised immediately as a gain in the income statement.

Other intangible assets

Intangible assets are stated at cost less provisions for amortisation and impairments.

Licences, patents, know-how and marketing rights separately acquired or acquired as part of a business combination are amortised over their estimated useful lives, generally not exceeding 20 years, using the straight-line basis, from the time they are available for use. The estimated useful lives for determining the amortisation charge take into account patent lives, where applicable, as well as the value obtained from periods of non-exclusivity. Asset lives are reviewed, and where appropriate adjusted, annually. Contingent milestone payments are recognised at the point that the contingent event becomes probable. Any development costs incurred by the Group and associated with acquired licences, patents, know-how or marketing rights are written off to the income statement when incurred, unless the criteria for recognition of an internally generated intangible asset are met, usually when a regulatory filing has been made in a major market and approval is considered highly probable.

Acquired brands are valued independently as part of the fair value of businesses acquired from third parties where the brand has a value which is substantial and long term and where the brands either are contractual or legal in nature or can be sold separately from the rest of the businesses acquired. Brands are amortised over their estimated useful lives of up to 20 years, except where it is considered that the useful economic life is indefinite.

The costs of acquiring and developing computer software for internal use and internet sites for external use are capitalised as intangible fixed assets where the software or site supports a significant business system and the expenditure leads to the creation of a durable asset. ERP systems software is amortised over seven to ten years and other computer software over three to five years.

Impairment of non-current assets

The carrying values of all non-current assets are reviewed for impairment, either on a stand-alone basis or as part of a larger cash generating unit, when there is an indication that the assets might be impaired. Additionally, goodwill, intangible assets with indefinite useful lives and intangible assets which are not yet available for use are tested for impairment annually. Any provision for impairment is charged to the income statement in the year concerned.

Impairments of goodwill are not reversed. Impairment losses on other non-current assets are only reversed if there has been a change in estimates used to determine recoverable amounts and only to the extent that the revised recoverable amounts do not exceed the carrying values that would have existed, net of depreciation or amortisation, had no impairments been recognised.

Investments in associates, joint ventures and joint operations

Investments in associates and joint ventures are carried in the consolidated balance sheet at the Group’s share of their net assets at date of acquisition and of their post-acquisition retained profits or losses together with any goodwill arising on the acquisition. The Group recognises its rights to assets, liabilities, revenue and expenses of joint operations.

Available-for-sale investments

Liquid investments and other investments are classified as available-for-sale investments and are initially recorded at fair value plus transaction costs and then remeasured at subsequent reporting dates to fair value. Unrealised gains and losses on available-for-sale investments are recognised directly in other comprehensive income. Impairments arising from the significant or prolonged decline in fair value of an equity investment reduce the carrying amount of the asset directly and are charged to the income statement.

On disposal or impairment of the investments, any gains and losses that have been deferred in other comprehensive income are reclassified to the income statement. Dividends on equity investments are recognised in the income statement when the Group’s right to receive payment is established. Equity investments are recorded in non-current assets unless they are expected to be sold within one year.

Purchases and sales of equity investments are accounted for on the trade date and purchases and sales of other available-for-sale investments are accounted for on settlement date.

Inventories

Inventories are included in the financial statements at the lower of cost (including raw materials, direct labour, other direct costs and related production overheads) and net realisable value. Cost is generally determined on a first in, first out basis. Pre-launch inventory is held as an asset when there is a high probability of regulatory approval for the product. Before that point a provision is made against the carrying value to its recoverable amount; the provision is then reversed at the point when a high probability of regulatory approval is determined.

Trade receivables

Trade receivables are carried at original invoice amount less any provisions for doubtful debts. Provisions are made where there is evidence of a risk of non-payment, taking into account ageing, previous experience and general economic conditions. When a trade receivable is determined to be uncollectable it is written off, firstly against any provision available and then to the income statement.

Subsequent recoveries of amounts previously provided for are credited to the income statement. Long-term receivables are discounted where the effect is material.

Borrowings

All borrowings are initially recorded at the amount of proceeds received, net of transaction costs. Borrowings are subsequently carried at amortised cost, with the difference between the proceeds, net of transaction costs, and the amount due on redemption being recognised as a charge to the income statement over the period of the relevant borrowing.

Taxation

Current tax is provided at the amounts expected to be paid applying tax rates that have been enacted or substantively enacted by the balance sheet date.

Deferred tax is provided in full, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the financial statements. Deferred tax assets are recognised to the extent that it is probable that future taxable profits will be available against which the temporary differences can be utilised. Deferred tax is provided on temporary differences arising on investments in subsidiaries, associates and joint ventures, except where the timing of the reversal of the temporary difference can be controlled and it is probable that the temporary difference will not reverse in the foreseeable future. Deferred tax is provided using rates of tax that have been enacted or substantively enacted by the balance sheet date.

Derivative financial instruments and hedging

Derivative financial instruments are used to manage exposure to market risks. The principal derivative instruments used by GSK are foreign currency swaps, interest rate swaps, foreign exchange forward contracts and options. The Group does not hold or issue derivative financial instruments for trading or speculative purposes.

Derivative financial instruments are classified as held-for-trading and are carried in the balance sheet at fair value. Derivatives designated as hedging instruments are classified on inception as cash flow hedges, net investment hedges or fair value hedges.

Changes in the fair value of derivatives designated as cash flow hedges are recognised in other comprehensive income to the extent that the hedges are effective. Ineffective portions are recognised in profit or loss immediately. Amounts deferred in other comprehensive income are reclassified to the income statement when the hedged item affects profit or loss.

Net investment hedges are accounted for in a similar way to cash flow hedges.

Changes in the fair value of derivatives designated as fair value hedges are recorded in the income statement, together with the changes in the fair value of the hedged asset or liability.

Changes in the fair value of any derivative instruments that do not qualify for hedge accounting are recognised immediately in the income statement.

Discounting

Where the time value of money is material, balances are discounted to current values using appropriate discount rates. The unwinding of the discounts is recorded in finance income and finance expense.

XML

Key accounting judgements and estimates

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Key accounting judgements and estimates

3. Key accounting judgements and estimates

In preparing the financial statements, management is required to make judgements about when or how items should be recognised in the financial statements and estimates and assumptions that affect the amounts of assets, liabilities, revenue and expenses reported in the financial statements. Actual amounts and results could differ from those estimates. The following are considered to be the key accounting judgements and estimates made.

Turnover

Reported Group turnover for 2017 was £30,186 million (2016 – £27,889 million).

Gross turnover is reduced by rebates, discounts, allowances and product returns given or expected to be given, which vary by product arrangements and buying groups. These arrangements with purchasing organisations are dependent upon the submission of claims some time after the initial recognition of the sale. Accruals are made at the time of sale for the estimated rebates, discounts or allowances payable or returns to be made, based on available market information and historical experience.

Because the amounts are estimated they may not fully reflect the final outcome, and the amounts are subject to change dependent upon, amongst other things, the types of buying group and product sales mix.

The level of accrual for rebates and returns is reviewed and adjusted regularly in the light of contractual and legal obligations, historical trends, past experience and projected market conditions. Market conditions are evaluated using wholesaler and other third-party analyses, market research data and internally generated information.

Future events could cause the assumptions on which the accruals are based to change, which could affect the future results of the Group.

Taxation

The tax charge for the year was £1,356 million (2016 – £877 million). At December 2017, current tax payable was £995 million (2016 – £1,305 million), non-current corporation tax payable was £411 million (2016 – £nil), current tax recoverable was £258 million (2016 – £226 million), deferred tax liabilities were £1,396 million (2016 – £1,934 million) and deferred tax assets were £3,796 million (2016 – £4,374 million).

Deferred tax assets are recognised when the judgement is made that it is probable that future taxable profits will be available against which the temporary differences can be utilised, based on management’s assumptions relating to the amounts and timing of future taxable profits. Factors affecting the tax charge in future years, in particular, US tax reform, are set out in Note 14, ‘Taxation’. A 1% change in the Group’s effective tax rate in 2017 would have changed the Total tax charge for the year by approximately £35 million.

The Group has open tax issues with a number of revenue authorities. Where management makes a judgement that an outflow of funds is probable and a reliable estimate of the outcome of the dispute can be made, provision is made for the best estimate of the liability. In estimating any such liability GSK applies a risk-based approach which takes into account, as appropriate, the probability that the Group would be able to obtain compensatory adjustments under international tax treaties. These estimates take into account the specific circumstances of each dispute and relevant external advice, are inherently judgemental and could change substantially over time as each dispute progresses and new facts emerge.

GSK continues to believe that it has made adequate provision for the liabilities likely to arise from open assessments. At 31 December 2017, the Group had recognised provisions of £1,175 million in respect of uncertain tax positions (2016 – £1,892 million). Where open issues exist the ultimate liability for such matters may vary from the amounts provided and is dependent upon the outcome of negotiations with the relevant tax authorities or, if necessary, litigation proceedings.

Legal and other disputes

Legal costs for the year were £166 million (2016 – £162 million). At 31 December 2017 provisions for legal and other disputes amounted to £186 million (2016 – £344 million).

The Group provides for anticipated settlement costs where management makes a judgement that an outflow of resources is probable and a reliable estimate can be made of the likely outcome of the dispute and legal and other expenses arising from claims against the Group. The estimated provisions take into account the specific circumstances of each dispute and relevant external advice, are inherently judgemental and could change substantially over time as each dispute progresses and new facts emerge. Details of the status and various uncertainties involved in the significant unresolved disputes are set out in Note 45, ‘Legal proceedings’.

The company’s Directors, having taken legal advice, have established provisions after taking into account the relevant facts and circumstances of each matter and in accordance with accounting requirements. In respect of product liability claims related to certain products there is sufficient history of claims made and settlements to enable management to make a reliable estimate of the provision required to cover unasserted claims. The Group may become involved in legal proceedings, in respect of which it is not possible to make a reliable estimate of the expected financial effect, if any, that could result from ultimate resolution of the proceedings. In these cases, appropriate disclosure about such cases would be provided, but no provision would be made and no contingent liability can be quantified.

The ultimate liability for legal claims may vary from the amounts provided and is dependent upon the outcome of litigation proceedings, investigations and possible settlement negotiations. The position could change over time and, therefore, there can be no assurance that any losses that result from the outcome of any legal proceedings will not exceed the amount of the provisions reported in the Group’s financial statements by a material amount.

Intangible asset impairments

At 31 December 2017, intangible assets were £17,562 million (2016 – £18,776 million).

Impairment tests on intangible assets are undertaken if events occur which call into question the carrying values of the assets. In addition, intangible assets with indefinite useful lives, or which are not yet available for use, are subject to annual impairment tests.

Valuations for impairment tests are based on established market multiples or risk-adjusted future cash flows over the estimated useful life of the asset, where limited, discounted using appropriate discount rates as set out in Note 19, ‘Other intangible assets’.

The assumptions relating to future cash flows, estimated useful lives and discount rates are based on business forecasts and are therefore inherently judgemental. Future events could cause the assumptions used in these impairment tests to change with a consequent adverse effect on the future results of the Group.

Contingent consideration and put option liabilities

The 2017 income statement charge for contingent consideration and put option liabilities was £2,134 million (2016 – £3,991 million).

At 31 December 2017, the liability for contingent consideration amounted to £6,172 million (2016 – £5,896 million). Of this amount, £5,542 million (2016 – £5,304 million) related to the acquisition of the former Shionogi-ViiV Healthcare joint venture in 2012 and £584 million (2016 – £545 million) related to the acquisition of the Vaccines business from Novartis in 2016.

Any contingent consideration included in the consideration payable for a business combination is recorded at fair value at the date of acquisition. These fair values are generally based on risk-adjusted future cash flows discounted using appropriate post-tax discount rates. The fair values are reviewed on a regular basis, at least annually, and any changes are reflected in the income statement. See Note 39, ‘Contingent consideration liabilities’.

During 2015, the Group granted a put option to Novartis in respect of Novartis’ shareholding in the Consumer Healthcare Joint Venture. In certain circumstances, Novartis has the right to require GSK to acquire its 36.5% shareholding in the Consumer Healthcare Joint Venture at a market-based valuation. This right is exercisable in certain windows from 2018 to 2035 and may be exercised either in respect of Novartis’ entire shareholding or in up to four instalments. GSK has recognised a financial liability of £8,606 million at 31 December 2017 (2016 – £7,420 million). This represents the present value of the redemption value estimated by GSK in the event of full exercise of the right by Novartis and is calculated by applying relevant public company multiples, with no premium or discount, to forecast future profits in accordance with the shareholder agreements. Sensitivity analysis is given in Note 27, ‘Trade and other payables’.

Pfizer may request an IPO of ViiV Healthcare at any time and if either GSK does not consent to such IPO or an offering is not completed within nine months, Pfizer could require GSK to acquire its shareholding. A liability for the put option was recognised on the Group’s balance sheet during 2016 at an initial value of £1,070 million. GSK also recognised liabilities for the future preferential dividends anticipated to become payable to Pfizer and Shionogi on the Group’s balance sheet during 2016. The liability for the Pfizer put option, which is derived from an internal valuation of the ViiV Healthcare business, utilising both discounted forecast future cash flow and multiples-based methodologies amounted to £1,304 million at 31 December 2017 (2016 – £1,319 million). Sensitivity analysis is also given in Note 27, ‘Trade and other payables’.

Pensions and other post-employment benefits

The costs of providing pensions and other post-employment benefits are assessed on the basis of assumptions selected by management. These assumptions include future earnings and pension increases, discount rates, expected long-term rates of return on assets and mortality rates, and are disclosed in Note 28, ‘Pensions and other post-employment benefits’. Where a surplus on a defined benefit scheme arises, or there is potential for a surplus to arise from committed future contributions, the rights of the Trustees to prevent the Group obtaining a refund of that surplus in the future are considered in determining whether it is necessary to restrict the amount of the surplus that is recognised.

Discount rates are derived from AA rated corporate bond yields except in countries where there is no deep market in corporate bonds where government bond yields are used. A sensitivity analysis is provided in Note 28, ‘Pensions and other post-employment benefits’, but a 0.25% reduction in the discount rate would lead to an increase in the net pension deficit of approximately £800 million and an increase in the annual pension cost of approximately £29 million. The selection of different assumptions could affect the future results of the Group.

XML

New accounting requirements

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

New accounting requirements

4. New accounting requirements

The following new and amended accounting standards have been issued by the IASB and are likely to affect future Annual Reports.

IFRS 15 ‘Revenue from contracts with customers’ was issued in May 2014 and has been implemented by the Group from 1 January 2018. The Standard provides a single, principles-based approach to the recognition of revenue from all contracts with customers. It focuses on the identification of performance obligations in a contract and requires revenue to be recognised when or as those performance obligations are satisfied.

The new Standard is not expected to have a material impact on the amount or timing of recognition of reported revenue. In its financial statements for 2018, GSK will adopt IFRS 15 applying the modified retrospective approach, with a cumulative adjustment to decrease equity at 1 January 2018 by approximately £4 million. In accordance with the requirements of the Standard where the modified retrospective approach is adopted, prior year results will not be restated.

IFRS 9 ‘Financial instruments’ was issued in its final form in July 2014 and has been implemented by the Group from 1 January 2018. The Standard replaces the majority of IAS 39 and covers the classification, measurement and de-recognition of financial assets and financial liabilities, introduces a new impairment model for financial assets based on expected losses rather than incurred losses and provides a new hedge accounting model.

The new Standard is not expected to have a material impact on reported results. In its financial statements for 2018, GSK will adopt IFRS 9 retrospectively, but with certain permitted exceptions. As a result, prior year results will not be restated, but there will be a cumulative adjustment to decrease equity at 1 January 2018 by approximately £11 million.

IFRS 16 ‘Leases’ was issued in January 2016 and will be implemented by the Group from 1 January 2019. The Standard will replace IAS 17 ‘Leases’ and will require lease liabilities and ‘right of use’ assets to be recognised on the balance sheet for almost all leases. This is expected to result in a significant increase in both assets and liabilities recognised. The costs of operating leases currently included within operating costs will be split and the financing element of the charge will be reported within finance expense. Finance lease obligations at 31 December 2017 are set out in Note 31, ‘Net debt’ and the undiscounted commitments under non-cancellable operating leases are set out in Note 41, ‘Commitments’.

The Group is assessing the potential impact of IFRS 16.

IFRIC 23 ‘Uncertainty over income tax treatments’ was issued in June 2017 and will be implemented by the Group from 1 January 2019. The Interpretation clarifies that if it is considered probable that a tax authority will accept an uncertain tax treatment, the tax charge should be calculated on that basis. If it is not considered probable, the effect of the uncertainty should be estimated and reflected in the tax charge. In assessing the uncertainty, it is assumed that the tax authority will have full knowledge of all information related to the matter.

The Group is continuing to assess the potential impact of the new Interpretation.

XML

Exchange rates

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Exchange rates

5. Exchange rates

The Group uses the average of exchange rates prevailing during the period to translate the results and cash flows of overseas subsidiaries, joint ventures and associates into Sterling and period end rates to translate the net assets of those entities. The currencies which most influence these translations and the relevant exchange rates were as follows:

	2017		2016		2015
Average rates:
US$/£		1.30		1.36		1.53
Euro/£		1.15		1.23		1.37
Yen/£		145		149		185
Period end rates:
US$/£		1.35		1.24		1.47
Euro/£		1.13		1.17		1.36
Yen/£		152		144		177

XML

Segment information

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Segment information

6. Segment information

Operating segments are reported based on the financial information provided to the Chief Executive Officer and the responsibilities of the Corporate Executive Team (CET). GSK reports results under four segments: Pharmaceuticals; Pharmaceuticals R&D; Vaccines and Consumer Healthcare, and individual members of the CET are responsible for each segment.

The Group’s management reporting process allocates intra-Group profit on a product sale to the market in which that sale is recorded, and the profit analyses below have been presented on that basis.

As explained on page 58, from 1 January 2017 only significant legal charges have been excluded from segment profit and reported within other reconciling items between segment profit and operating profit. Segment profits for 2016 and 2015 have been revised onto a comparable basis.

Corporate and other unallocated turnover and costs included the results of several Vaccines and Consumer Healthcare products which were held for sale in a number of markets in order to meet anti-trust approval requirements in 2015, together with the costs of corporate functions.

	2017		2016		2015
Turnover by segment	£m		£m		£m
Pharmaceuticals		17,276		16,104		14,157
Vaccines		5,160		4,592		3,656
Consumer Healthcare		7,750		7,193		6,038
Segment turnover		30,186		27,889		23,851
Corporate and other unallocated turnover		–		–		72
		30,186		27,889		23,923
	2017		2016		2015
Pharmaceuticals turnover by therapeutic area	£m		£m		£m
Respiratory		6,991		6,510		5,741
HIV		4,350		3,556		2,322
Immuno-inflammation		377		340		263
Established Pharmaceuticals		5,558		5,698		5,831
		17,276		16,104		14,157

During 2017, the US operations of the Pharmaceuticals and Vaccines businesses made sales to three wholesalers of approximately £2,449 million (2016 – £2,139 million; 2015 – £1,574 million), £3,043 million (2016 – £2,691 million; 2015 – £2,471 million) and £2,356 million (2016 – £2,129 million; 2015 – £1,602 million) respectively, after allocating final-customer discounts to the wholesalers.

	2017		2016		2015
Vaccines turnover by category	£m		£m		£m
Meningitis		890		662		326
Influenza		488		414		268
Shingles		22		–		–
Established Vaccines		3,760		3,516		3,062
		5,160		4,592		3,656
	2017		2016		2015
Consumer Healthcare turnover by category	£m		£m		£m
Wellness		4,001		3,726		2,970
Oral care		2,466		2,223		1,875
Nutrition		680		674		684
Skin health		603		570		509
		7,750		7,193		6,038

	2017			2016 (revised)			2015 (revised)
Segment profit	£m			£m			£m
Pharmaceuticals		8,667			7,976			6,449
Pharmaceuticals R&D		(2,740	)		(2,488	)		(2,168	)
Pharmaceuticals, including R&D		5,927			5,488			4,281
Vaccines		1,644			1,429			958
Consumer Healthcare		1,373			1,116			684
Segment profit		8,944			8,033			5,923
Corporate and other unallocated costs		(376	)		(362	)		(264	)
Other reconciling items between segment profit and operating profit		(4,481	)		(5,073	)		4,663
Operating profit		4,087			2,598			10,322
Finance income		65			72			104
Finance costs		(734	)		(736	)		(757	)
Profit on disposal of interest in associates		94			–			843
Share of after tax profits of associates and joint ventures		13			5			14
Profit before taxation		3,525			1,939			10,526
Taxation		(1,356	)		(877	)		(2,154	)
Profit after taxation for the year		2,169			1,062			8,372

Other reconciling items between segment profit and operating profit comprise items not specifically allocated to segment profit. These include impairment and amortisation of intangible assets, major restructuring charges, significant legal charges and expenses on the settlement of litigation and government investigations, disposals of businesses, products and associates, certain other items related to major acquisition and disposal activity and the pre-tax impact of the enactment of the US Tax Cuts and Jobs Act.

Depreciation and amortisation by segment	2017 £m		2016 £m		2015 £m
Pharmaceuticals		551		440		303
Pharmaceuticals R&D		96		211		238
Pharmaceuticals, including R&D		647		651		541
Vaccines		405		315		253
Consumer Healthcare		135		126		140
Segment depreciation and amortisation		1,187		1,092		934
Corporate and other unallocated depreciation and amortisation		144		94		145
Other reconciling items between segment depreciation and amortisation and total depreciation and amortisation		591		588		551
Total depreciation and amortisation		1,922		1,774		1,630

PP&E, intangible asset and goodwill impairment by segment	2017 £m		2016 £m		2015 £m
Pharmaceuticals		38		29		57
Pharmaceuticals R&D		10		88		105
Pharmaceuticals, including R&D		48		117		162
Vaccines		13		34		17
Consumer Healthcare		10		46		5
Segment impairment		71		197		184
Corporate and other unallocated impairment		3		24		18
Other reconciling items between segment impairment and total impairment		995		68		385
Total impairment		1,069		289		587

The other reconciling items between segment impairment and total impairment included £229 million related to the progressive withdrawal of Tanzeum.

PP&E and intangible asset impairment reversals by segment	2017 £m			2016 £m			2015 £m
Pharmaceuticals		(13	)		(15	)		(8	)
Pharmaceuticals R&D		(2	)		(10	)		(10	)
Pharmaceuticals, including R&D		(15	)		(25	)		(18	)
Vaccines		–			(19	)		–
Consumer Healthcare		(1	)		(8	)		(4	)
Segment impairment reversals		(16	)		(52	)		(22	)
Corporate and other unallocated impairment reversals		–			(26	)		(2	)
Other reconciling items between segment impairment reversals and total impairment reversals		(36	)		(9	)		–
Total impairment reversals		(52	)		(87	)		(24	)

	2017			2016
Net assets by segment	£m			£m
Pharmaceuticals		2,017			3,225
Pharmaceuticals R&D		522			572
Pharmaceuticals, including R&D		2,539			3,797
Vaccines		9,707			9,676
Consumer Healthcare		2,003			3,721
Segment net operating assets		14,249			17,194
Corporate and other unallocated net operating assets		868			(228	)
Net operating assets		15,117			16,966
Net debt		(13,178	)		(13,804	)
Investments in associates and joint ventures		183			263
Derivative financial instruments		2			(38	)
Current and deferred taxation		1,252			1,361
Assets held for sale		113			215
Net assets		3,489			4,963

The Pharmaceuticals segment includes the Shionogi-ViiV Healthcare contingent consideration liability of £5,542 million (2016 – £5,304 million) and the Pfizer put option of £1,304 million (2016 – £1,319 million). The Consumer Healthcare segment includes the put option liability of £8,606 million (2016 – £7,420 million).

Geographical information

The UK is regarded as being the Group’s country of domicile.

Turnover by location of customer	2017 £m		2016 £m		2015 £m
UK		940		1,056		1,102
US		11,263		10,197		8,222
International		17,983		16,636		14,599
External turnover		30,186		27,889		23,923
			2017		2016
Non-current assets by location of subsidiary			£m		£m
UK				6,824		7,060
US				6,841		7,802
International				20,901		21,234
Non-current assets				34,566		36,096

Non-current assets by location excludes amounts relating to other investments, deferred tax assets, derivative financial instruments, pension assets, amounts receivable under insurance contracts and certain other non-current receivables.

XML

Other operating income/(expense)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Other operating income/(expense)

7. Other operating income/(expense)

	2017			2016			2015
	£m			£m			£m
Impairment of equity investments		(30	)		(47	)		(263	)
Disposal of equity investments		37			254			342
Disposal of businesses and assets		195			283			9,661
Fair value remeasurements on contingent consideration recognised in business combinations		(1,012	)		(2,205	)		(1,965	)
Remeasurement of ViiV Healthcare put option liabilities and preferential dividends		13			(577	)		–
Remeasurement of Consumer Healthcare put option liability		(1,186	)		(1,133	)		(83	)
Fair value adjustments on derivative financial instruments		9			(3	)		2
Other income/(expense)		9			23			21
		(1,965	)		(3,405	)		7,715

Disposal of businesses and assets in 2017 included a profit of £250 million on the disposal of the anaesthesia business to Aspen. Disposals in 2016 included milestone income of £152 million in relation to the divestment of ofatumumab and a number of other smaller divestments and in 2015 included the disposal of the Oncology business to Novartis for £9,228 million and an initial £200 million for the divestment of ofatumumab.

Fair value remeasurements on contingent consideration recognised in business combinations included £909 million related to the acquisition of the former Shionogi-ViiV Healthcare joint venture and £53 million payable to Novartis related to the Vaccines acquisition. The fair value remeasurements on contingent consideration, the remeasurement of ViiV Healthcare put option liabilities and preferential dividends and the remeasurement of Consumer Healthcare put option liability include the additional charge arising from US tax reform of £666 million.

XML

Operating profit

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Operating profit

8. Operating profit

	2017			2016			2015
The following items have been included in operating profit:	£m			£m			£m
Employee costs (Note 9)		9,122			8,212			8,030
Advertising		1,351			1,265			1,059
Distribution costs		405			395			376
Depreciation of property, plant and equipment		988			978			892
Impairment of property, plant and equipment, net of reversals		327			180			346
Amortisation of intangible assets		934			796			738
Impairment of intangible assets, net of reversals		690			22			217
Net foreign exchange losses		215			53			47
Inventories:
Cost of inventories included in cost of sales		8,526			8,093			7,602
Write-down of inventories		701			533			488
Reversal of prior year write-down of inventories		(352	)		(145	)		(65	)
Operating lease rentals:
Minimum lease payments		110			91			101
Contingent rents		4			4			8
Sub-lease payments		5			4			7
Fees payable to the company’s auditor and its associates in relation to the Group (see below)		29.2			29.7			33.1

The reversals of prior year write-downs of inventories principally arise from the reassessment of usage or demand expectations prior to inventory expiration.

Net foreign exchange losses include a net loss of £109 million (2016 – £nil; 2015 – £nil) of exchange arising on the reclassification of exchange on liquidation or disposal of overseas subsidiaries.

Included within operating profit are major restructuring charges of £1,056 million (2016 – £970 million; 2015 – £1,891 million), see Note 10, ‘Major restructuring costs’.

Fees payable to the company’s auditor and its associates:	2017 £m		2016 £m		2015 £m
Audit of parent company and consolidated financial statements		7.0		5.8		7.5
Audit of the company’s subsidiaries		16.2		16.4		16.3
Attestation under s.404 of Sarbanes-Oxley Act 2002		4.5		4.4		4.3
Audit and audit-related services		27.7		26.6		28.1
Taxation compliance		0.2		0.2		0.3
Taxation advice		0.1		1.8		3.2
Other assurance services		1.0		0.3		1.1
All other services		0.2		0.8		0.4
		29.2		29.7		33.1

The other assurance services provided by the auditor relate to agreed upon procedures and other assurance services outside of statutory audit requirements. All other services provided by the auditor primarily related to advisory services for the year ended 31 December 2017.

In addition to the above, fees paid in respect of the GSK pension schemes were:

	2017 £m		2016 £m		2015 £m
Audit		0.3		0.4		0.3
Other services		0.1		—		—

XML

Employee costs

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Employee costs

9. Employee costs

	2017		2016		2015
	£m		£m		£m
Wages and salaries		7,116		6,391		6,132
Social security costs		802		733		633
Pension and other post-employment costs, including augmentations (Note 28)		616		541		467
Cost of share-based incentive plans		347		338		349
Severance and other costs from integration and restructuring activities		241		209		449
		9,122		8,212		8,030

The increase in wages and salaries included the impact of movements in exchange rates. The Group provides benefits to employees, commensurate with local practice in individual countries, including, in some markets, healthcare insurance, subsidised car schemes and personal life assurance.

The cost of share-based incentive plans is analysed as follows:

	2017 £m		2016 £m		2015 £m
Share Value Plan		276		271		307
Performance Share Plan		47		39		26
Share option plans		4		4		4
Cash settled and other plans		20		24		12
		347		338		349

The average monthly number of persons employed by the Group (including Directors) during the year was:

	2017 Number		2016 Number		2015 Number
Manufacturing		38,632		38,611		37,025
Selling, general and administration		49,141		49,961		52,121
Research and development		11,576		11,255		12,046
		99,349		99,827		101,192

The average monthly number of Group employees excludes temporary and contract staff. The numbers of Group employees at the end of each financial year are given in the financial record on page 250. The monthly average number of persons employed by GlaxoSmithKline plc in 2017 was nil (2016 – nil).

The compensation of the Directors and Senior Management (members of the CET) in aggregate, was as follows:

	2017 £m		2016 £m		2015 £m
Wages and salaries		26		25		23
Social security costs		4		4		2
Pension and other post-employment costs		3		2		3
Cost of share-based incentive plans		22		15		18
		55		46		46

XML

Major restructuring costs

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Major restructuring costs

10. Major restructuring costs

Major restructuring costs charged in arriving at operating profit include restructuring costs arising under the Major Change programme initiated in 2013, under the Pharmaceuticals Restructuring Programme announced in October 2014, following the Novartis transaction completed in 2015 and the CEO Strategic Initiatives Programme announced in July 2017.

The total restructuring costs of £1,056 million in 2017 were incurred in the following areas:

• Restructuring of the R&D organisation, predominantly in the United Kingdom and North America.

• Projects to simplify or eliminate processes leading to staff reductions in support functions.

• Restructuring of the Pharmaceuticals commercial operating model and supply chain leading to staff reductions in sales force and administration.

• Transformation of the manufacturing and Vaccines businesses to deliver a step change in quality, cost and productivity.

The costs charged to operating profit under these programmes were as follows:

	2017 £m			2016 £m			2015 £m
Increase in provision for major restructuring programmes (see Note 29)		259			163			718
Amount of provision reversed unused (see Note 29)		(43	)		(140	)		(44	)
Impairment losses recognised		278			158			419
Other non-cash charges		247			108			51
Other cash costs		315			681			747
		1,056			970			1,891

Provision reversals of £43 million (2016 – £140 million; 2015 – £44 million) reflected the release of legacy support function and Novartis integration provisions. Asset impairments of £278 million (2016 – £158 million; 2015 – £419 million) and other non-cash charges totalling £247 million (2016 – £108 million; 2015 – £51 million) are non-cash items, principally fixed asset write downs across support functions, manufacturing and research facilities and accelerated depreciation where asset lives in R&D and manufacturing have been shortened as a result of the major restructuring programme. All other charges have been or will be settled in cash and include the termination of leases, site closure costs, consultancy and project management fees.

XML

Finance income

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Finance income

11. Finance income

	2017		2016		2015
	£m		£m		£m
Interest income arising from:
cash and cash equivalents		60		67		71
available-for-sale investments		2		1		1
derivatives at fair value through profit or loss		—		—		24
loans and receivables		1		2		3
Fair value adjustments on derivatives at fair value through profit or loss		2		2		5
		65		72		104

All derivatives accounted for at fair value through profit or loss other than designated and effective hedging instruments (see Note 42, ‘Financial instruments and related disclosures’) are classified as held-for-trading financial instruments under IAS 39.

XML

Finance expense

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Finance expense

12. Finance expense

	2017			2016			2015
	£m			£m			£m
Interest expense arising on:
financial liabilities at amortised cost		(698	)		(671	)		(655	)
derivatives at fair value through profit or loss		(22	)		(30	)		(64	)
Fair value movements on other derivatives at fair value through profit or loss		(4	)		(3	)		(6	)
Reclassification of cash flow hedge from other comprehensive income		—			(1	)		(2	)
Unwinding of discounts on provisions		(16	)		(16	)		(16	)
Other finance expense		6			(15	)		(14	)
		(734	)		(736	)		(757	)

All derivatives accounted for at fair value through profit or loss, other than designated and effective hedging instruments (see Note 42, ‘Financial instruments and related disclosures’), are classified as held-for-trading financial instruments under IAS 39. Interest expense arising on derivatives at fair value through profit or loss relates to swap interest expense. Other finance expense includes a £24 million credit for interest relating to income taxes (see Note 1, ‘Presentation of the financial statements’). The amounts for 2016 and 2015 were not material and so comparatives have not been restated.

XML

Associates and joint ventures

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Associates and joint ventures

13. Associates and joint ventures

The Group’s share of after tax profits and losses of associates and joint ventures is set out below:

	2017 £m			2016 £m			2015 £m
Share of after tax profits of associates		16			9			16
Share of after tax losses of joint ventures		(3	)		(4	)		(2	)
		13			5			14

At 31 December 2017, the Group held one significant associate, Innoviva, Inc.

Summarised income statement information in respect of Innoviva is set out below for the periods in which the Group accounted for its investment in Innoviva as an associate. The Group’s 2017 share of after tax profits of associates and other comprehensive income includes a profit of £18 million and other comprehensive income of £nil in respect of Innoviva.

					Since
					1 September
	2017		2016		2015
	£m		£m		£m
Turnover		165		98		20
Profit after taxation		103		44		4
Other comprehensive income		—		—		—
Total comprehensive income		103		44		4

The results of Innoviva included in the summarised income statement information above represent the estimated earnings of Innoviva in the relevant periods. Innoviva’s turnover is from royalty income from GSK in relation to Relvar/Breo Ellipta, Anoro Ellipta and Trelegy Ellipta sales.

Aggregated financial information in respect of GSK’s share of other associated undertakings and joint ventures is set out below:

	2017 £m			2016 £m			2015 £m
Share of turnover		252			133			188
Share of after tax (losses)/profits		(5	)		(1	)		12
Share of other comprehensive income		—			—			25
Share of total comprehensive (expense)/income		(5	)		(1	)		37

The Group’s sales to associates and joint ventures were £41 million in 2017 (2016 – £43 million; 2015 – £41 million).

XML

Taxation

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Taxation

14. Taxation

The Group’s tax charge is the sum of the total current and deferred tax expense.

Taxation charge based on profits for the year	2017 £m			2016 £m			2015 £m
UK current year charge		199			241			156
Rest of World current year charge		1,928			1,326			2,924
Credit in respect of prior periods		(508	)		(149	)		(508	)
Total current taxation		1,619			1,418			2,572
Total deferred taxation		(263	)		(541	)		(418	)
Total tax		1,356			877			2,154

In 2017, GSK made payments of £212 million in UK corporation tax to HMRC. These amounts are for UK corporation tax only, and do not include the various other business taxes borne in the UK by GSK each year.

The deferred tax credit in 2017 reflected the revaluation of existing deferred tax liabilities to reflect a lower Swiss tax rate applicable following Swiss tax reform, and an increase in deferred tax assets related to intra-Group profit on inventory. The impact of these items was partly offset by the revaluation of existing deferred tax assets to reflect the lower headline US tax rate following enactment of US tax reform. In comparison to 2017, the 2016 and 2015 net deferred tax credits were impacted to a greater extent by remeasurements of the contingent consideration in relation to the former Shionogi-ViiV Healthcare joint venture. In 2015, the credit also included the unwind of deferred tax liabilities on the disposal of the Group’s Oncology business to Novartis.

The following table reconciles the tax charge calculated at the UK statutory rate on the Group profit before tax with the actual tax charge for the year.

Reconciliation of taxation on Group profits	2017 £m			2017 %			2016 £m			2016 %			2015 £m			2015 %
Profit before tax		3,525						1,939						10,526
UK statutory rate of taxation		679			19.25			388			20.0			2,131			20.25
Differences in overseas taxation rates		635			18.0			593			30.6			1,035			9.8
Benefit of intellectual property incentives		(458	)		(13.0	)		(321	)		(16.5	)		(286	)		(2.7	)
R&D credits		(75	)		(2.1	)		(93	)		(4.8	)		(38	)		(0.4	)
Remeasurement of non-taxable put option liabilities		227			6.4			340			17.5			17			0.2
Losses not recognised/(previously unrecognised losses)		28			0.8			(15	)		(0.8	)		31			0.3
Permanent differences on disposals and acquisitions		4			0.1			(21	)		(1.1	)		(248	)		(2.4	)
Other permanent differences		196			5.6			97			5.0			58			0.6
Reassessment of prior year estimates in respect of current and deferred taxes		(475	)		(13.5	)		(116	)		(6.0	)		(578	)		(5.5	)
US and Swiss tax reform		595			16.9
Tax on unremitted earnings		—			—			25			1.3			32			0.3
Tax charge/tax rate		1,356			38.5			877			45.2			2,154			20.5

GSK has a substantial business presence in many countries around the globe. The impact of differences in overseas taxation rates arose from profits being earned in countries with tax rates higher than the UK statutory rate, the most significant of which in 2017 were the US, Belgium, and India.

The adverse impact was partly offset by the increased benefit of intellectual property incentives such as the UK Patent Box and Belgian Patent Income Deduction regimes. Such regimes provide a reduced rate of corporate income tax on profits earned from qualifying patents.

The Group’s 2017 tax rate of 38.5% has been influenced by the impact of US and Swiss tax reforms, together with transaction-related charges arising on the Group’s put option liabilities in relation to ViiV Healthcare and the Consumer Healthcare Joint Venture and the reassessment of estimates of uncertain tax positions following the settlement of a number of open issues with tax authorities in various jurisdictions.

Included within Other permanent differences is a £34 million charge that arises following the enactment of Belgium tax reform during 2017.

Future tax charges, and therefore the Group’s effective tax rate, may be affected by factors such as acquisitions, disposals, restructurings, the location of research and development activity, tax regime reforms and resolution of open matters as we continue to bring our tax affairs up to date around the world.

	2017			2016		2015
Tax on items charged to equity and statement of comprehensive income	£m			£m		£m
Current taxation
Share-based payments		—			7		22
Defined benefit plans		26			32		30
		26			39		52
Deferred taxation
Share-based payments		(4	)		—		(12	)
Defined benefit plans		(247	)		94		(110	)
Exchange movements		—			—		—
Fair value movements on cash flow hedges		—			2		—
Fair value movements on available-for-sale investments		29			51		(55	)
		(222	)		147		(177	)
Total (charge)/credit to equity and statement of comprehensive income		(196	)		186		(125	)

All of the above items have been charged to the statement of comprehensive income except for tax on share based payments.

Following enactment of US and Belgian tax reform, the Group has recognised deferred tax charges of £27 million and £25 million respectively to equity and the statement of comprehensive income. Both amounts are included within the £222 million net deferred tax charge presented above.

International tax reform

The Group’s tax charge has been influenced by the impact of international tax reform enacted during the year. The US Tax Cuts and Jobs Act (‘the Act’) is expected to have a positive impact on the future after tax earnings of GSK’s US businesses. However, enactment of the new law in 2017 has resulted in a number of non-recurring charges. In addition, enactment of Swiss tax reform during 2017 resulted in a non-recurring tax credit arising from the revaluation of deferred tax liabilities relating to certain Consumer Healthcare brands, acquired from Novartis in 2015, to reflect a reduction in the headline Swiss tax rate.

The charges associated with US tax reform are based on the information currently available. As further guidance from the US Treasury on implementation of the Act becomes available, particularly with regard to the repatriation tax provisions, the assumptions underlying these estimates could change. This could result in adjustments to the charges taken that could have a material impact on the results of the Group.

The impact of tax reform on profits attributable to shareholders in 2017 is set out below.

	Swiss tax		US tax
	reform		reform
	£m		£m
Other operating expenses		—		(666	)
Current tax		—		(273	)
Deferred tax		483		(805	)
Impact on profit after taxation for the year		483		(1,744	)
Profit attributable to non-controlling interests		176		(114	)
Profit attributable to shareholders		307		(1,630	)

The valuations of the HIV and Consumer Healthcare businesses have increased due to lower US tax rates. This has resulted in an increase in the related liabilities for contingent consideration and the put options and hence an additional operating cost of £666 million. The current tax charge in respect of US tax reform relates primarily to the introduction of a repatriation tax on the accumulated reserves of non-US subsidiaries of US entities in the Group, the cash impact of which will be spread over eight years from 2018 onwards. The deferred tax charge relates primarily to the revaluation of existing balance sheet tax assets held against future liabilities, such as pensions.

The tax charge associated with US tax reform was partly offset by an allocation to non-controlling interests amounting to £114 million, as many of the adjustments related to ViiV Healthcare and the Consumer Healthcare Joint Venture. The tax credit associated with Swiss tax reform was similarly offset with a £176 million charge due to an allocation to non-controlling interests related to the Consumer Healthcare Joint Venture. The impact on the tax charge arising from US tax reform was as follows:

	Current tax			Deferred tax			Total
	£m			£m			£m
Revaluation of assets and liabilities		75			(805	)		(730	)
Repatriation tax		(348	)		—			(348	)
		(273	)		(805	)		(1,078	)

The Group also incurred a charge of £34 million following the enactment of Belgian tax reform during 2017, predominantly relating to the revaluation of existing deferred tax assets.

Continued focus on tax reform is expected in 2018 and future years driven by the OECD’s Base Erosion and Profit Shifting (“BEPS”) project and European Commission initiatives including fiscal state aid investigations. Together with domestic initiatives around the world these may result in significant changes to established tax principles and an increase in tax authority disputes. In turn, this could adversely affect GSK’s effective tax rate or could result in higher cash tax liabilities.

Issues relating to taxation

The integrated nature of the Group’s worldwide operations involves significant investment in research and strategic manufacture at a limited number of locations, with consequential cross-border supply routes into numerous end-markets. In line with current OECD guidelines the Group base our transfer pricing policy on the ‘arm’s length’ principle. However, different tax authorities may seek to attribute further profit to activities being undertaken in their jurisdiction, potentially resulting in double taxation. The Group also has open items in several jurisdictions concerning such matters as the deductibility of particular expenses and the tax treatment of certain business transactions. GSK applies a risk-based approach to determine the transactions most likely to be subject to challenge and the probability that the Group would be able to obtain compensatory adjustments under international tax treaties.

The calculation of the Group’s total tax charge therefore necessarily involves a degree of estimation and judgment in respect of certain items whose tax treatment cannot be finally determined until resolution has been reached with the relevant tax authority or, as appropriate, through a formal legal process. At 31 December 2017 the Group had recognised provisions of £1,175 million in respect of such uncertain tax positions (2016 – £1,892 million). The decrease in recognised provisions during 2017 was driven by the reassessment of estimates and the utilisation of provisions for uncertain tax positions following the settlement of a number of open issues with tax authorities in various jurisdictions. The transfer of accrued interest payable on tax balances to ‘Other payables’ and the foreign exchange impact of revaluing overseas exposures also contributed to the reduction in recognised provisions. Whilst the ultimate liability for such matters may vary from the amounts provided and is dependent upon the outcome of agreements with the relevant tax authorities, or litigation where appropriate, the Group continues to believe that it has made appropriate provision for periods which are open and not yet agreed by the tax authorities. We do not currently anticipate any material changes to the amounts provided for transfer pricing or tax contingencies during the next 12 months.

A provision for deferred tax liabilities of £209 million (2016 – £205 million) has been made in respect of withholding taxation that would arise on the distribution of profits by certain overseas subsidiaries. Whilst the aggregate amount of unremitted profits at the balance sheet date was approximately £17 billion (2016 – £18 billion), the majority of these unremitted profits would not be subject to tax (including withholding tax) on repatriation, as UK legislation relating to company distributions provides for exemption from tax for most overseas profits, subject to certain exceptions. In prior years, a temporary difference arose on the accumulated reserves of non-US subsidiaries of US entities in the Group. As the timing of reversal of this temporary difference could be controlled and was not considered probable in the foreseeable future, deferred tax had not been provided. However, as a result of the US Tax Cuts and Jobs Act, the temporary difference reversed and the Group recorded a one-off repatriation tax charge of £348 million. Accordingly, the unremitted profits on which deferred tax has not been provided is now £nil (2016 – £1.7 billion).

Movement in deferred tax assets and liabilities

													Pensions &						Share			Other
	Accelerated												other post						option			net
	capital			Intangible			Contingent			Intra-Group			employment			Tax			and award			temporary
	allowances			assets			consideration			profit			benefits			losses			schemes			differences			Total
	£m			£m			£m			£m			£m			£m			£m			£m			£m
At 1 January 2017		(377	)		(2,324	)		1,138			1,054			1,262			227			110			1,350			2,440
Exchange adjustments		(7	)		75			—			(58	)		(48	)		(5	)		(4	)		(18	)		(65	)
Credit/(charge) to income statement		62			330			(52	)		256			3			59			(1	)		(88	)		569
Credit/(charge) to income statement associated with US tax reform		5			116			(218	)		(235	)		(210	)		(20	)		(27	)		(216	)		(805	)
Credit to income statement associated with Swiss tax reform		—			483			—			—			—			—			—			—			483
(Charge)/credit to statement of comprehensive income and equity		—			—			—			—			(247	)		—			(4	)		29			(222	)
At 31 December 2017		(317	)		(1,320	)		868			1,017			760			261			74			1,057			2,400

The net deferred tax credit of £247 million to the income statement included a £483 million credit associated with Swiss tax reform and a £569 million credit in relation to the origination and reversal of temporary differences. These credits were partly offset by a £805 million charge in relation to US tax reform. The net credit to the income statement of £247 million included a £16 million charge related to R&D incentives recognised within Operating profit (and not the taxation charge) in the income statement.

Deferred tax liabilities provided in relation to intangible assets predominately relate to temporary differences arising on assets and liabilities acquired as part of historic business combinations. The Group continues to recognise deferred tax assets on future obligations in respect of contingent consideration amounts payable to minority shareholders. These payments are tax deductible at the point in time at which payment is made.

A deferred tax asset is recognised on intra-Group profits arising on inter-company inventory which are eliminated within the consolidated financial statements. As intra-Group profits are not eliminated from the individual entities’ tax returns a temporary difference arises that will reverse at the point in time inventory is sold externally. The deferred tax asset recognised on tax losses of £261 million related to trading losses. In 2016, £173 million related to trading losses and £54 million related to capital losses. Other net temporary differences included accrued expenses for which a tax deduction is only available on a paid basis, such as rebates.

Deferred tax assets and liabilities are recognised on the balance sheet as follows:

	2017			2016
	£m			£m
Deferred tax assets		3,796			4,374
Deferred tax liabilities		(1,396	)		(1,934	)
		2,400			2,440

Deferred tax assets are recognised on US foreign tax credits only where it is possible that future taxable profits will be available. The gross amount of foreign tax credits on which deferred tax has not been recognised was £721 million at 31 December 2017.

Deferred tax assets are recognised where it is probable that future taxable profit will be available to utilise losses. Unrecognised tax losses are as follows:

	2017				2016
			Unrecognised				Unrecognised
			deferred tax				deferred tax
	Tax losses		asset		Tax losses		asset
Unrecognised tax losses	£m		£m		£m		£m
Trading losses expiring:
Within 10 years		802		187		786		255
More than 10 years		872		99		842		131
Available indefinitely		86		14		95		15
At 31 December		1,760		300		1,723		401
Capital losses		1,924		372		2,320		396
At 31 December		1,924		372		2,320		396

XML

Earnings per share

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Earnings per share

15. Earnings per share

	2017		2016		2015
	pence		pence		pence
Basic earnings per share		31.4		18.8		174.3
Diluted earnings per share		31.0		18.6		172.3

Basic earnings per share has been calculated by dividing the profit attributable to shareholders by the weighted average number of shares in issue during the period after deducting shares held by the ESOP Trusts and Treasury shares. The trustees have waived their rights to dividends on the shares held by the ESOP Trusts.

Diluted earnings per share has been calculated after adjusting the weighted average number of shares used in the basic calculation to assume the conversion of all potentially dilutive shares. A potentially dilutive share forms part of the employee share schemes where its exercise price is below the average market price of GSK shares during the period and any performance conditions attaching to the scheme have been met at the balance sheet date.

The numbers of shares used in calculating basic and diluted earnings per share are reconciled below.

	2017		2016		2015
Weighted average number of shares in issue	millions		millions		millions
Basic		4,886		4,860		4,831
Dilution for share options and awards		55		49		57
Diluted		4,941		4,909		4,888

XML

Dividends

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Dividends

16. Dividends

	2017						2016						2015
			Dividend		Total				Dividend		Total				Dividend		Total
			per share		dividend				per share		dividend				per share		dividend
	Paid/payable		(pence)		£m		Paid		(pence)		£m		Paid		(pence)		£m
First interim		13 July 2017		19		928		14 July 2016		19		923		9 July 2015		19		920
Second interim		12 October 2017		19		929		13 October 2016		19		925		1 October 2015		19		919
Third interim		11 January 2018		19		929		12 January 2017		19		925		14 January 2016		19		919
Fourth interim		12 April 2018		23		1,125		13 April 2017		23		1,124		14 April 2016		23		1,114
Total				80		3,911				80		3,897				80		3,872
Special dividend														14 April 2016		20		969

Under IFRS interim dividends are only recognised in the financial statements when paid and not when declared. GSK normally pays a dividend two quarters after the quarter to which it relates and one quarter after it is declared. The 2017 financial statements recognise those dividends paid in 2017, namely the third and fourth interim dividends for 2016, and the first and second interim dividends for 2017.

The amounts recognised in each year were as follows:

	2017		2016		2015
	£m		£m		£m
Dividends to shareholders		3,906		4,850		3,874

XML

Property, plant and equipment

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Property, plant and equipment

17. Property, plant and equipment

				Plant,
	Land and			equipment			Assets in
	buildings			and vehicles			construction			Total
	£m			£m			£m			£m
Cost at 1 January 2016		7,305			10,775			2,670			20,750
Exchange adjustments		956			1,100			271			2,327
Other additions		117			384			1,043			1,544
Capitalised borrowing costs		—			—			30			30
Disposals and write-offs		(349	)		(1,422	)		(53	)		(1,824	)
Reclassifications		110			512			(761	)		(139	)
Transfer to assets held for sale		(378	)		(114	)		(32	)		(524	)
Cost at 31 December 2016		7,761			11,235			3,168			22,164
Exchange adjustments		(127	)		(62	)		(45	)		(234	)
Other additions		69			296			1,219			1,584
Capitalised borrowing costs		—			—			30			30
Disposals and write-offs		(376	)		(685	)		(31	)		(1,092	)
Reclassifications		602			1,186			(1,826	)		(38	)
Transfer to assets held for sale		(462	)		(219	)		(14	)		(695	)
Cost at 31 December 2017		7,467			11,751			2,501			21,719
Depreciation at 1 January 2016		(2,914	)		(7,415	)		—			(10,329	)
Exchange adjustments		(377	)		(717	)		—			(1,094	)
Charge for the year		(338	)		(640	)		—			(978	)
Disposals and write-offs		205			1,270			—			1,475
Transfer to assets held for sale		165			92			—			257
Depreciation at 31 December 2016		(3,259	)		(7,410	)		—			(10,669	)
Exchange adjustments		50			110			—			160
Charge for the year		(299	)		(689	)		—			(988	)
Disposals and write-offs		158			539			—			697
Transfer to assets held for sale		314			190			—			504
Depreciation at 31 December 2017		(3,036	)		(7,260	)		—			(10,296	)
Impairment at 1 January 2016		(274	)		(373	)		(106	)		(753	)
Exchange adjustments		(45	)		(37	)		(11	)		(93	)
Disposals and write-offs		91			135			35			261
Impairment losses		(135	)		(117	)		(6	)		(258	)
Reversal of impairments		38			38			2			78
Transfer to assets held for sale		46			10			22			78
Impairment at 31 December 2016		(279	)		(344	)		(64	)		(687	)
Exchange adjustments		8			2			(2	)		8
Disposals and write-offs		210			104			28			342
Impairment losses		(194	)		(138	)		(17	)		(349	)
Reversal of impairments		7			9			1			17
Transfer to assets held for sale		87			8			11			106
Impairment at 31 December 2017		(161	)		(359	)		(43	)		(563	)
Total depreciation and impairment at 31 December 2016		(3,538	)		(7,754	)		(64	)		(11,356	)
Total depreciation and impairment at 31 December 2017		(3,197	)		(7,619	)		(43	)		(10,859	)
Net book value at 1 January 2016		4,117			2,987			2,564			9,668
Net book value at 31 December 2016		4,223			3,481			3,104			10,808
Net book value at 31 December 2017		4,270			4,132			2,458			10,860

The weighted average interest rate for capitalised borrowing costs in the year was 4% (2016 – 3.8%). Disposals and write-offs in the year include a number of assets with nil net book value that are no longer in use in the business.

The net book value at 31 December 2017 of the Group’s land and buildings comprised freehold properties £3,896 million (2016 – £3,887 million), properties with leases of 50 years or more £338 million (2016 – £294 million) and properties with leases of less than 50 years £36 million (2016 – £42 million).

Included in land and buildings at 31 December 2017 were leased assets with a cost of £630 million (2016 – £590 million), accumulated depreciation of £255 million (2016 – £253 million), impairment of £nil (2016 – £1 million) and a net book value of £375 million (2016 – £336 million). Included in plant, equipment and vehicles at 31 December 2017 were leased assets with a cost of £18 million (2016 – £44 million), accumulated depreciation of £4 million (2016 – £15 million), impairment of £1 million (2016 – £nil) and a net book value of £13 million (2016 – £29 million). Some lease agreements include renewal or purchase options or escalation clauses.

The impairment losses principally arose from decisions to rationalise facilities and are calculated based on either fair value less costs of disposal or value in use. The fair value less costs of disposal valuation methodology uses significant inputs which are not based on observable market data, and therefore this valuation technique is classified as level 3 of the fair value hierarchy. These calculations determine the net present value of the projected risk-adjusted, post-tax cash flows of the relevant asset or cash generating unit, applying a discount rate of the Group post-tax weighted average cost of capital (WACC) of 7%, adjusted where appropriate for relevant specific risks. For value in use calculations, where an impairment is indicated and a pre-tax cash flow calculation is expected to give a materially different result, the test would be reperformed using pre-tax cash flows and a pre-tax discount rate. The Group WACC is equivalent to a pre-tax discount rate of approximately 9%. The net impairment losses have been charged to cost of sales £198 million (2016 – £45 million), R&D £93 million (2016 – £15 million) and SG&A £36 million (2016 – £120 million), and included £278 million (2016 – £151 million) arising from the major restructuring programmes.

Reversals of impairment arose from subsequent reviews of the impaired assets where the conditions which gave rise to the original impairments were deemed no longer to apply. All of the reversals have been credited to cost of sales.

The carrying value at 31 December 2017 of assets for which impairments have been charged or reversed in the year was £33 million (2016 – £171 million).

During 2017, £38 million (2016 – £139 million) of computer software was reclassified from assets in construction to intangible assets on becoming ready for use.

XML

Goodwill

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Goodwill

18. Goodwill

	2017			2016
	£m			£m
Cost at 1 January		5,965			5,162
Exchange adjustments		(228	)		814
Additions through business combinations (Note 38)		—			7
Transfer to assets held for sale		(3	)		(18	)
Cost at 31 December		5,734			5,965
Net book value at 1 January		5,965			5,162
Net book value at 31 December		5,734			5,965
Goodwill is allocated to the Group’s segments as follows:
	2017			2016
	£m			£m
Pharmaceuticals		3,172			3,288
Vaccines		1,302			1,353
Consumer Healthcare		1,260			1,324
Net book value at 31 December		5,734			5,965

The recoverable amounts of the cash generating units are assessed using a fair value less costs of disposal model. Fair value less costs of disposal is calculated using a discounted cash flow approach, with a post-tax discount rate applied to the projected risk-adjusted post-tax cash flows and terminal value.

The discount rate used is based on the Group WACC of 7%, as most cash generating units have integrated operations across large parts of the Group. The discount rate is adjusted where appropriate for specific country or currency risks. The valuation methodology uses significant inputs which are not based on observable market data, therefore this valuation technique is classified as level 3 in the fair value hierarchy.

Details relating to the discounted cash flow models used in the impairment tests of the Pharmaceuticals, Vaccines and Consumer Healthcare cash generating units are as follows:

Valuation basis	Fair value less costs of disposal
Key assumptions	Sales growth rates
	Profit margins
	Terminal growth rate
	Discount rate
	Taxation rate
Determination of assumptions	Growth rates are internal forecasts based on both internal and external market information.
	Margins reflect past experience, adjusted for expected changes.
	Terminal growth rates based on management’s estimate of future long-term average growth rates.
	Discount rates based on Group WACC, adjusted where appropriate.
	Taxation rates based on appropriate rates for each region.
Period of specific projected cash flows	Five years
Terminal growth rate and discount rate		Terminal growth rate		Discount rate
	Pharmaceuticals		1% p.a.		7%
	Vaccines		2% p.a.		7%
	Consumer Healthcare		2% p.a.		7%

The terminal growth rates do not exceed the long-term projected growth rates for the relevant markets, reflect the impact of future generic competition and take account of new product launches.

In each case the valuations indicated sufficient headroom such that a reasonably possible change to key assumptions is unlikely to result in an impairment of the related goodwill. Goodwill is monitored at the segmental level.

The Pharmaceuticals cash generating unit comprises a collection of smaller cash generating units including assets with indefinite lives with a carrying value of £228 million (2016 – £211 million). The Consumer Healthcare cash generating unit also comprises a collection of smaller cash generating units including brands with indefinite lives with a carrying value of £8.51 billion (2016 – £9.03 billion).

Details of indefinite life brands are given in Note 19, ‘Other intangible assets’.

XML

Other intangible assets

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Other intangible assets

19. Other intangible assets

	Computer			Licences,			Amortised			Indefinite life
	software			patents, etc.			brands			brands			Total
	£m			£m			£m			£m			£m
Cost at 1 January 2016		2,028			13,394			387			8,074			23,883
Exchange adjustments		137			1,139			20			1,320			2,616
Capitalised development costs		—			219			21			—			240
Capitalised borrowing costs		4			—			—			—			4
Additions through business combinations		—			102			—			—			102
Other additions		238			349			—			—			587
Disposals and asset write-offs		(389	)		(21	)		(1	)		(7	)		(418	)
Transfer to assets held for sale		(1	)		(39	)		—			(12	)		(52	)
Reclassifications		139			—			—			—			139
Cost at 31 December 2016		2,156			15,143			427			9,375			27,101
Exchange adjustments		(37	)		(215	)		(4	)		(272	)		(528	)
Capitalised development costs		—			251			—			—			251
Capitalised borrowing costs		2			3			—			—			5
Other additions		233			221			—			—			454
Disposals and asset write-offs		(217	)		(38	)		—			—			(255	)
Transfer to assets held for sale		(1	)		(90	)		—			(44	)		(135	)
Reclassifications		38			—			66			(66	)		38
Cost at 31 December 2017		2,174			15,275			489			8,993			26,931
Amortisation at 1 January 2016		(1,294	)		(4,030	)		(133	)		—			(5,457	)
Exchange adjustments		(92	)		(410	)		(5	)		—			(507	)
Charge for the year		(152	)		(553	)		(91	)		—			(796	)
Disposals and asset write-offs		353			—			5			—			358
Transfer to assets held for sale		1			10			—			—			11
Amortisation at 31 December 2016		(1,184	)		(4,983	)		(224	)		—			(6,391	)
Exchange adjustments		25			141			—			—			166
Charge for the year		(163	)		(761	)		(10	)		—			(934	)
Disposals and asset write-offs		210			25			—			—			235
Transfer to assets held for sale		1			25			—			—			26
Amortisation at 31 December 2017		(1,111	)		(5,553	)		(234	)		—			(6,898	)
Impairment at 1 January 2016		(39	)		(1,439	)		(154	)		(122	)		(1,754	)
Exchange adjustments		(3	)		(266	)		—			(3	)		(272	)
Impairment losses		(2	)		(15	)		—			(5	)		(22	)
Disposals and asset write-offs		35			40			11			—			86
Transfer to assets held for sale		—			28			—			—			28
Impairment at 31 December 2016		(9	)		(1,652	)		(143	)		(130	)		(1,934	)
Exchange adjustments		—			110			—			3			113
Impairment losses		(2	)		(546	)		—			(132	)		(680	)
Disposals and asset write-offs		2			5			—			—			7
Transfer to assets held for sale		—			19			—			4			23
Impairment at 31 December 2017		(9	)		(2,064	)		(143	)		(255	)		(2,471	)
Total amortisation and impairment at 31 December 2016		(1,193	)		(6,635	)		(367	)		(130	)		(8,325	)
Total amortisation and impairment at 31 December 2017		(1,120	)		(7,617	)		(377	)		(255	)		(9,369	)
Net book value at 1 January 2016		695			7,925			100			7,952			16,672
Net book value at 31 December 2016		963			8,508			60			9,245			18,776
Net book value at 31 December 2017		1,054			7,658			112			8,738			17,562

The weighted average interest rate for capitalised borrowing costs in the year was 4% (2016 – 3.8%).

The net book value of computer software included £669 million (2016 – £620 million) of internally generated costs.

The charge for impairments in the year included £229 million related to the progressive withdrawal of the pharmaceutical product, Tanzeum, which was fully impaired. The carrying value at 31 December 2017 of intangible assets, for which impairments have been charged or reversed in the year, following those impairments or reversals, was £300 million (2016 – £116 million).

The patent expiry dates of the Group’s most significant assets, where relevant, are set out on pages 254 and 255.

Amortisation and impairment losses, net of reversals, have been charged in the income statement as follows:

	Amortisation				Net impairment losses
	2017		2016		2017		2016
	£m		£m		£m		£m
Cost of sales		578		582		400		7
Selling, general and administration		116		95		2		2
Research and development		240		119		278		13
		934		796		680		22

Licences, patents, etc. includes a large number of acquired licences, patents, know-how agreements and marketing rights, which are either marketed or in use, or still in development. Note 38, ‘Acquisitions and disposals’ gives details of additions through business combinations in the year. The book values of the largest individual items are as follows:

	2017		2016
	£m		£m
Meningitis portfolio		2,450		2,511
dolutegravir		1,389		1,487
Benlysta		965		1,019
Fluarix/FluLaval		321		380
HIV assets acquired from BMS		277		277
Selzentry		162		188
Okairos technology platform		202		173
Others		1,892		2,473
		7,658		8,508

The Meningitis portfolio includes Menveo, Bexsero and Men ABCWY.

Indefinite life brands comprise a portfolio of Consumer Healthcare products primarily acquired with the acquisitions of Sterling Winthrop, Inc. in 1994, Block Drug Company, Inc. in 2001, CNS, Inc. in 2006 and the Novartis Consumer Healthcare business in 2015, together with a number of pharmaceutical brands from the acquisition of Stiefel Laboratories, Inc. in 2009. The book values of the major brands are as follows:

	2017		2016
	£m		£m
Voltaren		2,716		2,847
Otrivin		1,380		1,447
Fenistil		648		680
Theraflu		441		462
Panadol		386		354
Sensodyne		265		243
Lamisil		289		304
Breathe Right		236		199
Stiefel trade name		228		211
Excedrin		185		194
Physiogel		166		166
Polident		112		103
Others		1,686		2,035
		8,738		9,245

Each of these brands is considered to have an indefinite life, given the strength and durability of the brand and the level of marketing support. The brands are in relatively similar stable and profitable market sectors, with similar risk profiles, and their size, diversification and market shares mean that the risk of market-related factors causing a reduction in the lives of the brands is considered to be relatively low. The Group is not aware of any material legal, regulatory, contractual, competitive, economic or other factors which could limit their useful lives. Accordingly, they are not amortised.

Each brand is tested annually for impairment and other amortised intangible assets are tested when indicators of impairment arise. This testing applies a fair value less costs of disposal methodology, generally using post-tax cash flow forecasts with a terminal value calculation and a discount rate equal to the Group post-tax WACC of 7%, adjusted where appropriate for specific country and currency risks. This valuation methodology uses significant inputs which are not based on observable market data, and therefore this valuation technique is classified as level 3 of the fair value hierarchy. The main assumptions include future sales price and volume growth, product contribution, the future expenditure required to maintain the product’s marketability and registration in the relevant jurisdictions and exchange rates. These assumptions are based on past experience and are reviewed as part of management’s budgeting and strategic planning cycle for changes in market conditions and sales erosion through competition. The terminal growth rates applied of between nil% and 5% are management’s estimates of future long-term average growth rates of the relevant markets. In each case the valuations indicate sufficient headroom such that a reasonably possible change to key assumptions is unlikely to result in an impairment of these intangible assets.

XML

Investments in associates and joint ventures

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Investments in associates and joint ventures

20. Investments in associates and joint ventures

	Joint						2017			Joint						2016
	ventures			Associates			Total			ventures			Associates			Total
	£m			£m			£m			£m			£m			£m
At 1 January		19			244			263			20			187			207
Exchange adjustments		(2	)		(10	)		(12	)		4			41			45
Additions		—			15			15			3			8			11
Disposals		—			(92	)		(92	)		—			—			—
Distributions received		(1	)		(1	)		(2	)		(2	)		(1	)		(3	)
Other movements		—			(2	)		(2	)		(2	)		—			(2	)
(Loss)/profit after tax recognised in the consolidated income statement		(3	)		16			13			(4	)		9			5
At 31 December		13			170			183			19			244			263

The Group held one significant associate at 31 December 2017, Innoviva, Inc. At 31 December 2017, the Group owned 32 million shares or 31.4% of Innoviva, which is a biopharmaceutical company listed on NASDAQ. Innoviva partnered with GSK in the development of the long acting beta agonist vilanterol and currently receives royalty income from sales of products that contain this component, namely Relvar/Breo Ellipta, Anoro Ellipta and Trelegy Ellipta. The remaining 85% of the economic interest in these royalties will be due to Theravance Biopharma Inc., a company spun out of Innoviva in 2014, in which the Group holds 17.8% of the common stock. The investment in Innoviva had a market value of £336 million at 31 December 2017 (2016 – £278 million).

In 2017, the Group divested its shareholdings in two associates, see Note 38, ‘Acquisitions and disposals’.

Summarised balance sheet information, based on results information, in respect of Innoviva is set out below:

	At 31 December			At 31 December
	2017			2016
	£m			£m
Non-current assets		124			146
Current assets		148			160
Current liabilities		(26	)		(16	)
Non-current liabilities		(426	)		(575	)
Net liabilities		(180	)		(285	)
	2017			2016
	£m			£m
Interest in associated undertaking		(57	)		(84	)
Goodwill		86			84
Fair value and other adjustments		118			138
Carrying value at 31 December		147			138

XML

Other investments

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Other investments

21. Other investments

	2017			2016
	£m			£m
At 1 January		985			1,255
Exchange adjustments		(64	)		211
Additions		80			96
Net fair value movements		11			130
Impairment losses		(30	)		(24	)
Disposals		(64	)		(683	)
At 31 December		918			985

Other investments comprise non-current equity investments which are available-for-sale investments recorded at fair value at each balance sheet date. For investments traded in an active market, the fair value is determined by reference to the relevant stock exchange quoted bid price. For other investments, the fair value is estimated by management with reference to relevant available information, including the current market value of similar instruments and discounted cash flows of the underlying net assets. Other investments include listed investments of £535 million (2016 – £580 million). The most significant of the investments held at 31 December 2017 was in Theravance Biopharma, Inc. in which the Group holds 17.8% of the common stock. This investment had a fair value at 31 December 2017 of £199 million (2016 – £248 million). The other investments include equity stakes in companies with which GSK has research collaborations and in companies which provide access to biotechnology developments of potential interest.

On disposal of investments, fair value movements are reclassified from equity to the income statement based on average cost for shares acquired at different times.

The impairment losses recorded above have been recognised in the income statement for the year within Other operating income, together with amounts reclassified from the fair value reserve on recognition of the impairments. These impairments initially result from prolonged or significant declines in the fair value of the equity investments below acquisition cost, subsequent to which any further declines in fair value are immediately taken to the income statement.

The carrying value at 31 December of Other investments which have been impaired is as follows:

	2017			2016
	£m			£m
Original cost		475			515
Cumulative impairments recognised in the income statement		(283	)		(314	)
Subsequent fair value increases		210			282
Carrying value at 31 December		402			483

XML

Other non-current assets

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Other non-current assets

22. Other non-current assets

	2017		2016
	£m		£m
Amounts receivable under insurance contracts		648		602
Pension schemes in surplus		538		313
Other receivables		227		284
		1,413		1,199

XML

Inventories

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Inventories

23. Inventories

	2017		2016
	£m		£m
Raw materials and consumables		1,193		1,068
Work in progress		2,381		2,299
Finished goods		1,983		1,735
		5,557		5,102

XML

Trade and other receivables

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Trade and other receivables

24. Trade and other receivables

	2017		2016
	£m		£m
Trade receivables, net of provision for bad and doubtful debts		4,672		4,615
Accrued income		21		64
Other prepayments		308		335
Interest receivable		10		11
Employee loans and advances		19		17
Other receivables		970		984
		6,000		6,026

Trade receivables included £11 million (2016 – £9 million) due from associates and joint ventures. Other receivables included £7 million (2016 – £7 million) due from associates and joint ventures.

	2017			2016
Bad and doubtful debt provision	£m			£m
At 1 January		207			167
Exchange adjustments		(4	)		23
Charge for the year		31			77
Subsequent recoveries of amounts provided for		(79	)		(59	)
Utilised		(15	)		(1	)
At 31 December		140			207

XML

Cash and cash equivalents

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Cash and cash equivalents

25. Cash and cash equivalents

	2017		2016
	£m		£m
Cash at bank and in hand		826		1,462
Short-term deposits		3,007		3,435
		3,833		4,897

XML

Assets held for sale

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Assets held for sale

26. Assets held for sale

	2017		2016
	£m		£m
Property, plant and equipment		57		184
Goodwill		—		13
Other intangibles		49		12
Inventory		7		7
Other		—		(1	)
		113		215

Included within Assets held for sale is £31 million of intangible impairments, £10 million PP&E impairments, £21 million intangible impairment reversals and £15 million PP&E impairment reversals.

Non-current assets and disposal groups are transferred to assets held for sale when it is expected that their carrying amounts will be recovered principally through disposal and a sale is considered highly probable. They are held at the lower of carrying amount and fair value less costs to sell.

Included within Assets held for sale are assets which were written down to fair value less costs to sell of £63 million (2016 – £79 million). The valuation methodology uses significant inputs which are not based on observable market data, therefore, this valuation is classified as level 3 in the fair value hierarchy.

XML

Trade and other payables

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Trade and other payables

27. Trade and other payables

	2017		2016
	£m		£m
Trade payables		3,528		3,596
Wages and salaries		1,228		1,236
Social security		166		120
Consumer Healthcare put option		8,606		—
ViiV Healthcare put option		1,304		1,319
Other payables		363		447
Deferred income		240		158
Customer return and rebate accruals		3,463		2,778
Other accruals		2,072		2,310
		20,970		11,964

Trade and other payables included £53 million (2016 – £36 million) due to associates and joint ventures.

Customer return and rebate accruals are provided for by the Group at the point of sale in respect of the estimated rebates, discounts or allowances payable to customers, and included £2,837 million (2016 – £2,218 million) in respect of US Pharmaceuticals and Vaccines, as more fully described in the Group financial review on page 76. Accruals are made at the time of sale but the actual amounts paid are based on claims made some time after the initial recognition of the sale. As the amounts are estimated, they may not fully reflect the final outcome and are subject to change dependent upon, amongst other things, the types of buying group and product sales mix. The level of accrual is reviewed and adjusted quarterly in light of historical experience of actual rebates, discounts or allowances given and returns made and any changes in arrangements. Future events could cause the assumptions on which the accruals are based to change, which could affect the future results of the Group.

The Consumer Healthcare put option liability relates to the ability of Novartis to put its shares in the Consumer Healthcare Joint Venture to GSK at certain points in the future. As this option became exercisable from 2 March 2018, with payment likely to be due several months after exercise, it has been classified within current liabilities. The liability is recorded at the present value of the estimated redemption value, applying a discount rate of 7%, calculated by applying an average of relevant public company multiples approach with no premium or discount, based on the forecast profits and earnings of the Consumer Healthcare Joint Venture, which forms part of GSK’s Consumer Healthcare segment. The remeasurement charge in the year was £1,186 million, including the impact of US tax reform (2016 – £1,133 million), see Note 7, ‘Other operating income/(expense)’. The table below shows on an indicative basis the income statement and balance sheet sensitivity to reasonably possible changes in key assumptions.

	2017
Increase/(decrease) in financial liability and loss/(gain) in Income statement	£m
10% increase in sales forecasts or sales multiple applied		850
10% decrease in sales forecasts or sales multiple applied		(850	)
10 cent appreciation of US Dollar		88
10 cent depreciation of US Dollar		(76	)
10 cent appreciation of Euro		303
10 cent depreciation of Euro		(254	)

Pfizer’s put option over its shareholding in ViiV Healthcare was recognised during 2016 and is currently exercisable. The table below shows on an indicative basis the income statement and balance sheet sensitivity of the Pfizer put option to reasonably possible changes in key assumptions.

	2017
Increase/(decrease) in financial liability and loss/(gain) in Income statement	£m
10% increase in sales forecasts		150
10% decrease in sales forecasts		(149	)
10 cent appreciation of US Dollar		76
10 cent depreciation of US Dollar		(66	)
10 cent appreciation of Euro		44
10 cent depreciation of Euro		(37	)

An explanation of the accounting for ViiV Healthcare is set out on page 59.

XML

Pensions and other post-employment benefits

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Pensions and other post-employment benefits

28. Pensions and other post-employment benefits

	2017		2016		2015
Pension and other post-employment costs	£m		£m		£m
UK pension schemes		198		205		177
US pension schemes		113		106		96
Other overseas pension schemes		218		140		135
Unfunded post-retirement healthcare schemes		87		90		59
		616		541		467
Analysed as:
Funded defined benefit/hybrid pension schemes		335		304		291
Unfunded defined benefit pension schemes		55		43		36
Unfunded post-retirement healthcare schemes		87		90		59
Defined benefit schemes		477		437		386
Defined contribution pension schemes		139		104		81
		616		541		467

The costs of the defined benefit pension and post-retirement healthcare schemes are charged in the income statement as follows:

	2017		2016		2015
	£m		£m		£m
Cost of sales		162		135		127
Selling, general and administration		238		221		194
Research and development		77		81		65
		477		437		386

GSK entities operate pension arrangements which cover the Group’s material obligations to provide pensions to retired employees. These arrangements have been developed in accordance with local practices in the countries concerned. Pension benefits can be provided by state schemes; by defined contribution schemes, whereby retirement benefits are determined by the value of funds arising from contributions paid in respect of each employee; or by defined benefit schemes, whereby retirement benefits are based on employee pensionable remuneration and length of service.

Pension costs of defined benefit schemes for accounting purposes have been calculated using the projected unit method. In certain countries pension benefits are provided on an unfunded basis, some administered by trustee companies. Formal, independent, actuarial valuations of the Group’s main plans are undertaken regularly, normally at least every three years.

Actuarial movements in the year are recognised through the statement of comprehensive income. Discount rates are derived from AA rated corporate bond yields except in countries where there is no deep market in corporate bonds where government bond yields are used. Discount rates are selected to reflect the term of the expected benefit payments. Projected inflation rate and pension increases are long-term predictions based on the yield gap between long-term index-linked and fixed interest Gilts. In the UK, mortality rates are determined by adjusting the SAPS S2 standard mortality tables to reflect recent scheme experience. These rates are then projected to reflect improvements in life expectancy in line with the CMI 2016 projections with a long-term rate of improvement of 1.25% per year for both males and females. In the US, mortality rates are calculated using the RP2014 white collar table adjusted to reflect recent experience. These rates are projected using MP-2017 to allow for future improvements in life expectancy.

The average life expectancy assumed now for an individual at the age of 60 and projected to apply in 2037 for an individual then at the age of 60 is as follows:

	UK				US
	Male Years		Female Years		Male Years		Female Years
Current		27.5		29.5		26.9		28.6
Projected for 2037		29.1		31.1		28.6		30.3

The assets of funded schemes are generally held in separately administered trusts, either as specific assets or as a proportion of a general fund, or are insurance contracts. Assets are invested in different classes in order to maintain a balance between risk and return. Investments are diversified to limit the financial effect of the failure of any individual investment. The Group reviewed the investment strategy of the UK plans in 2011 and the asset allocation for the UK plans has been adjusted to approximately 55% return seeking assets and 45% liability matching assets. In 2013, the target asset allocation of the US plans was also updated to 55% return seeking assets and 45% liability matching assets.

The Pension Plans are exposed to risk that arises because the estimated market value of the Plans’ assets might decline, the investment returns might reduce, or the estimated value of the Plans’ liabilities might increase.

In line with the agreed mix of return seeking assets to generate future returns and liability matching assets to better match future pension obligations, the Group has defined an overall long-term investment strategy for the Plans, with investments across a broad range of assets. The main market risks within the asset and hedging portfolio are against credit risk, interest rates, long-term inflation, equities, property, and bank counterparty risk.

The Plan liabilities are a series of future cash flows with relatively long duration. On an IAS 19R basis, these cash flows are sensitive to changes in the expected long-term inflation rate and the discount rate (AA corporate bond yield curve) where an increase in long-term inflation corresponds with an increase in the liabilities, and an increase in the discount rate corresponds with a decrease in the liabilities.

In the UK the defined benefit pension schemes operated for the benefit of former Glaxo Wellcome employees and former SmithKline Beecham employees remain separate. These schemes were closed to new entrants in 2001 and subsequent UK employees are entitled to join a defined contribution scheme. In the US the former Glaxo Wellcome and SmithKline Beecham defined benefit schemes were merged during 2001. In addition, the Group operates a number of post-retirement healthcare schemes, the principal one of which is in the US.

The Group has applied the following financial assumptions in assessing the defined benefit liabilities:

	UK						US						Rest of World
	2017 % pa		2016 % pa		2015 % pa		2017 % pa		2016 % pa		2015 % pa		2017 % pa		2016 % pa		2015 % pa
Rate of increase of future earnings		2.00		2.00		2.00		4.00		4.00		4.00		2.80		2.70		2.70
Discount rate		2.50		2.70		3.80		3.60		3.90		4.20		1.60		1.60		2.20
Expected pension increases		3.20		3.20		3.10		n/a		n/a		n/a		2.20		2.10		2.00
Cash balance credit/conversion rate		n/a		n/a		n/a		2.90		3.20		3.20		0.30		0.30		0.60
Inflation rate		3.20		3.20		3.10		2.25		2.25		2.25		1.70		1.50		1.40

The amounts recorded in the income statement and statement of comprehensive income for the three years ended 31 December 2017 in relation to the defined benefit pension and post-retirement healthcare schemes were as follows:

	Pensions												Post-retirement benefits
2017	UK £m			US £m			Rest of World £m			Group £m			Group £m
Amounts charged to operating profit
Current service cost		79			70			131			280			30
Past service cost		37			—			—			37			(2	)
Net interest cost		7			31			16			54			59
Expenses		7			12			—			19			—
		130			113			147			390			87
Remeasurement gains/(losses) recorded in the statement of comprehensive income		259			240			(14	)		485			64
	Pensions												Post-retirement benefits
2016	UK £m			US £m			Rest of World £m			Group £m			Group £m
Amounts charged to operating profit
Current service cost		70			66			110			246			31
Past service cost		52			1			1			54			3
Net interest cost		9			27			20			56			56
Gains from settlements		—			—			(28	)		(28	)		—
Expenses		7			12			—			19			—
		138			106			103			347			90
Remeasurement losses recorded in the statement of comprehensive income		(165	)		(27	)		(224	)		(416	)		(59	)
	Pensions												Post-retirement benefits
2015	UK £m			US £m			Rest of World £m			Group £m			Group £m
Amounts charged to operating profit
Current service cost		77			67			110			254			22
Past service cost/(credit)		25			2			(10	)		17			(8	)
Net interest cost		14			22			13			49			52
Losses/(gains) from settlements		—			1			(9	)		(8	)		(7	)
Expenses		7			4			4			15			—
		123			96			108			327			59
Remeasurement gains/(losses) recorded in the statement of comprehensive income		82			(30	)		147			199			62

The amounts included within past service costs include £37 million (2016 – £52 million; 2015 – £25 million) of augmentation costs of which £18 million is arising from major restructuring programmes (see Note 29, ‘Other provisions’).

A summarised balance sheet presentation of the Group defined benefit pension schemes and other post-retirement benefits is set out in the table below:

	2017			2016			2015
	£m			£m			£m
Recognised in Other non-current assets:
Pension schemes in surplus		538			313			258
Recognised in Pensions and other post-employment benefits:
Pension schemes in deficit		(2,043	)		(2,397	)		(1,842	)
Post-retirement benefits		(1,496	)		(1,693	)		(1,387	)
		(3,539	)		(4,090	)		(3,229	)

The fair values of the assets and liabilities of the UK and US defined benefit pension schemes, together with aggregated data for other defined benefit pension schemes in the Group are as follows:

		UK			US			Rest of World			Group
At 31 December 2017		£m			£m			£m			£m
Equities:	– listed		4,902			1,448			544			6,894
	– unlisted		—			—			13			13
Multi-asset funds			2,517			—			—			2,517
Property:	– unlisted		352			209			32			593
Corporate bonds:	– listed		297			820			103			1,220
	– unlisted		326			—			20			346
Government bonds:	– listed		5,127			239			762			6,128
Insurance contracts			849			—			707			1,556
Other assets			(1,216	)		158			71			(987	)
Fair value of assets			13,154			2,874			2,252			18,280
Present value of scheme obligations			(13,101	)		(3,445	)		(3,239	)		(19,785	)
Net surplus/(obligation)			53			(571	)		(987	)		(1,505	)
Included in Other non-current assets			470			—			68			538
Included in Pensions and other post-employment benefits			(417	)		(571	)		(1,055	)		(2,043	)
			53			(571	)		(987	)		(1,505	)
Actual return on plan assets			893			394			82			1,369

The multi-asset funds comprise investments in pooled investment vehicles that are invested across a range of asset classes, increasing diversification within the growth portfolio.

The index-linked gilts held as part of the UK repo programme are included in government bonds. The related loan is included within ‘Other assets’ at a value of £(773) million (2016 – £(1,698) million; 2015 – £(2,215) million).

		UK			US			Rest of World			Group
At 31 December 2016		£m			£m			£m			£m
Equities:	– listed		5,357			1,358			486			7,201
	– unlisted		—			—			14			14
Multi-asset funds			1,545			—			—			1,545
Property:	– unlisted		314			216			28			558
Corporate bonds:	– listed		292			213			96			601
	– unlisted		321			—			24			345
Government bonds:	– listed		6,165			815			739			7,719
Insurance contracts			856			—			637			1,493
Other assets			(2,267	)		288			73			(1,906	)
Fair value of assets			12,583			2,890			2,097			17,570
Present value of scheme obligations			(12,884	)		(3,752	)		(3,018	)		(19,654	)
Net obligation			(301	)		(862	)		(921	)		(2,084	)
Included in Other non-current assets			276			—			37			313
Included in Pensions and other post-employment benefits			(577	)		(862	)		(958	)		(2,397	)
			(301	)		(862	)		(921	)		(2,084	)
Actual return on plan assets			2,473			153			99			2,725

At 31 December 2015		UK £m			US £m			Rest of World £m			Group £m
Equities:	– listed		5,187			1,235			355			6,777
	– unlisted		—			—			1			1
Multi-asset funds			481			—			—			481
Property:	– unlisted		302			175			8			485
Corporate bonds:	– listed		251			727			76			1,054
	– unlisted		232			—			2			234
Government bonds:	– listed		5,687			184			664			6,535
Insurance contracts			755			—			439			1,194
Other assets			(2,611	)		180			205			(2,226	)
Fair value of assets			10,284			2,501			1,750			14,535
Present value of scheme obligations			(10,601	)		(3,134	)		(2,384	)		(16,119	)
Net obligation			(317	)		(633	)		(634	)		(1,584	)
Included in Other non-current assets			232			—			26			258
Included in Pensions and other post-employment benefits			(549	)		(633	)		(660	)		(1,842	)
			(317	)		(633	)		(634	)		(1,584	)
Actual return on plan assets			(17	)		(30	)		23			(24	)

													Post-retirement
	Pensions												benefits
	UK			US			Rest of World			Group			Group
Movements in fair values of assets	£m			£m			£m			£m			£m
Assets at 1 January 2015		10,551			2,531			1,529			14,611			—
Exchange adjustments		—			147			(52	)		95			—
Additions through business combinations		—			—			233			233			—
Interest income		374			95			33			502			—
Expenses		(7	)		(4	)		(4	)		(15	)		—
Settlements and curtailments		—			—			(16	)		(16	)		—
Remeasurement		(391	)		(125	)		(10	)		(526	)		—
Employer contributions		164			132			112			408			82
Scheme participants’ contributions		4			—			14			18			14
Benefits paid		(411	)		(275	)		(89	)		(775	)		(96	)
Assets at 31 December 2015		10,284			2,501			1,750			14,535			—
Exchange adjustments		—			459			305			764			—
Interest income		385			108			37			530			—
Expenses		(7	)		(12	)		—			(19	)		—
Settlements and curtailments		—			—			(110	)		(110	)		—
Remeasurement		2,088			45			62			2,195			—
Employer contributions		319			31			131			481			91
Scheme participants’ contributions		4			—			14			18			17
Benefits paid		(490	)		(242	)		(92	)		(824	)		(108	)
Assets at 31 December 2016		12,583			2,890			2,097			17,570			—
Exchange adjustments		—			(244	)		24			(220	)		—
Interest income		333			104			33			470			—
Expenses		(7	)		(12	)		—			(19	)		—
Settlements and curtailments		—			—			(4	)		(4	)		—
Remeasurement		560			290			49			899			—
Employer contributions		225			103			116			444			101
Scheme participants’ contributions		4			—			17			21			17
Benefits paid		(544	)		(257	)		(80	)		(881	)		(118	)
Assets at 31 December 2017		13,154			2,874			2,252			18,280			—

During 2017, the Group made special funding contributions to the UK pension schemes totalling £136 million (2016 – £191 million; 2015 – £85 million) and £78 million (2016 – £nil; 2015 – £111 million) to the US scheme. In 2016, GSK reached an agreement with the trustees of the UK pension schemes to make additional contributions to eliminate the pension deficit identified at the 31 December 2014 actuarial funding valuation. Based on the funding agreements following the 2014 valuation, the additional contributions to eliminate the pension deficit are expected to be £123 million in 2018. The contributions were based on a government bond yield curve approach to selecting the discount rate; the rate chosen included an allowance for expected investment returns which reflected the asset mix of the schemes.

Employer contributions for 2018, including special funding contributions, are estimated to be approximately £360 million in respect of defined benefit pension schemes and £90 million in respect of post-retirement benefits.

													Post-retirement
	Pensions												benefits
	UK			US			Rest of World			Group			Group
Movements in defined benefit obligations	£m			£m			£m			£m			£m
Obligations at 1 January 2015		(10,991	)		(3,133	)		(2,176	)		(16,300	)		(1,397	)
Exchange adjustments		—			(184	)		78			(106	)		(64	)
Additions through business combinations		—			—			(397	)		(397	)		(11	)
Service cost		(77	)		(67	)		(110	)		(254	)		(22	)
Past service cost		(25	)		(2	)		10			(17	)		8
Interest cost		(388	)		(117	)		(46	)		(551	)		(52	)
Settlements and curtailments		—			(1	)		25			24			7
Remeasurement		473			95			157			725			62
Scheme participants’ contributions		(4	)		—			(14	)		(18	)		(14	)
Benefits paid		411			275			89			775			96
Obligations at 31 December 2015		(10,601	)		(3,134	)		(2,384	)		(16,119	)		(1,387	)
Exchange adjustments		—			(586	)		(396	)		(982	)		(248	)
Service cost		(70	)		(66	)		(110	)		(246	)		(31	)
Past service cost		(52	)		(1	)		(1	)		(54	)		(3	)
Interest cost		(394	)		(135	)		(57	)		(586	)		(56	)
Settlements and curtailments		—			—			138			138			—
Remeasurement		(2,253	)		(72	)		(286	)		(2,611	)		(59	)
Scheme participants’ contributions		(4	)		—			(14	)		(18	)		(17	)
Benefits paid		490			242			92			824			108
Obligations at 31 December 2016		(12,884	)		(3,752	)		(3,018	)		(19,654	)		(1,693	)
Exchange adjustments		—			305			(45	)		260			119
Service cost		(79	)		(70	)		(131	)		(280	)		(30	)
Past service cost		(37	)		—			—			(37	)		2
Interest cost		(340	)		(135	)		(49	)		(524	)		(59	)
Settlements and curtailments		—			—			4			4			—
Remeasurement		(301	)		(50	)		(63	)		(414	)		64
Scheme participants’ contributions		(4	)		—			(17	)		(21	)		(17	)
Benefits paid		544			257			80			881			118
Obligations at 31 December 2017		(13,101	)		(3,445	)		(3,239	)		(19,785	)		(1,496	)

The defined benefit pension obligation is analysed as follows:

	2017			2016			2015
	£m			£m			£m
Funded		(19,052	)		(18,974	)		(15,552	)
Unfunded		(733	)		(680	)		(567	)
		(19,785	)		(19,654	)		(16,119	)

The liability for the US post-retirement healthcare scheme has been assessed using the same assumptions as for the US pension scheme, together with the assumption for future medical inflation of 6.75% (2016 – 7%), grading down to 5.0% in 2025 and thereafter. At 31 December 2017, the US post-retirement healthcare scheme obligation was £1,254 million (2016 – £1,463 million; 2015 – £1,208 million). Post-retirement benefits are unfunded.

The movement in the net defined benefit liability is as follows:

	2017			2016			2015
	£m			£m			£m
At 1 January		(2,084	)		(1,584	)		(1,689	)
Exchange adjustments		40			(218	)		(11	)
Additions through business combinations		—			—			(164	)
Service cost		(280	)		(246	)		(254	)
Past service cost		(37	)		(54	)		(17	)
Interest cost		(54	)		(56	)		(49	)
Settlements and curtailments		—			28			8
Remeasurements:
Return on plan assets, excluding amounts included in interest		899			2,195			(526	)
Gain from change in demographic assumptions		209			85			120
(Loss)/gain from change in financial assumptions		(555	)		(2,770	)		362
Experience (losses)/gains		(68	)		74			243
Employer contributions		444			481			408
Expenses/other movements		(19	)		(19	)		(15	)
At 31 December		(1,505	)		(2,084	)		(1,584	)
The remeasurements included within post-retirement benefits are detailed below:
	2017			2016			2015
	£m			£m			£m
Gain from change in demographic assumptions		47			—			15
(Loss)/gain from change in financial assumptions		(1	)		(81	)		59
Experience gains/(losses)		18			22			(12	)
		64			(59	)		62

The defined benefit pension obligation analysed by membership category is as follows:

	2017 £m		2016 £m		2015 £m
Active		4,611		4,576		5,510
Retired		9,805		9,574		7,969
Deferred		5,369		5,504		4,231
		19,785		19,654		17,710
The post-retirement benefit obligation analysed by membership category is as follows:
	2017 £m		2016 £m		2015 £m
Active		514		594		499
Retired		981		1,099		887
Deferred		1		—		1
		1,496		1,693		1,387
The weighted average duration of the defined benefit obligation is as follows:
	2017 years		2016 years		2015 years
Pension benefits		16		16		16
Post-retirement benefits		11		12		12

Sensitivity analysis

Effect of changes in assumptions used on the benefit obligations and on the 2018 annual defined benefit pension and post retirement costs.

	£m
A 0.25% decrease in discount rate would have the following approximate effect:
Increase in annual pension cost		29
Decrease in annual post-retirement benefits cost		(1	)
Increase in pension obligation		800
Increase in post-retirement benefits obligation		41
A one year increase in life expectancy would have the following approximate effect:
Increase in annual pension cost		20
Increase in annual post-retirement benefits cost		2
Increase in pension obligation		608
Increase in post-retirement benefits obligation		39
A 1% increase in the rate of future healthcare inflation would have the following approximate effect:
Increase in annual post-retirement benefits cost		2
Increase in post-retirement benefits obligation		68
A 0.25% increase in inflation would have the following approximate effect:
Increase in annual pension cost		19
Increase in pension obligation		502

XML

Other provisions

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Other provisions

29. Other provisions

	Legal			Major			Employee
	and other			restructuring			related			Other
	disputes			programmes			provisions			provisions			Total
	£m			£m			£m			£m			£m
At 1 January 2017		344			554			306			296			1,500
Exchange adjustments		(29	)		(16	)		(8	)		(6	)		(59	)
Charge for the year		173			259			50			69			551
Reversed unused		(7	)		(43	)		(3	)		(36	)		(89	)
Unwinding of discount		2			4			—			10			16
Utilised		(288	)		(233	)		(41	)		(67	)		(629	)
Reclassifications and other movements		(9	)		(3	)		—			5			(7	)
Transfer to Pension obligations		—			(18	)		—			—			(18	)
At 31 December 2017		186			504			304			271			1,265
To be settled within one year		138			292			90			109			629
To be settled after one year		48			212			214			162			636
At 31 December 2017		186			504			304			271			1,265

Legal and other disputes

The Group is involved in a substantial number of legal and other disputes, including notification of possible claims, as set out in Note 45 ‘Legal proceedings’. Provisions for legal and other disputes include amounts relating to product liability, anti-trust, government investigations, contract terminations, self insurance and environmental clean-up.

The charge for the year of £166 million (net of reversals and estimated insurance recoveries) primarily related to provisions for product liability cases regarding Paxil and other products, commercial disputes and various other government investigations.

The discount on the provisions increased by £2 million in 2017 (2016 – increased by £1 million). The discount was calculated using risk-adjusted projected cash flows and risk-free rates of return.

In respect of product liability claims related to certain products, there is sufficient history of claims made and settlements to enable management to make a reliable estimate of the provision required to cover unasserted claims. The ultimate liability for such matters may vary from the amounts provided and is dependent upon the outcome of litigation proceedings, investigations and possible settlement negotiations.

It is in the nature of the Group’s business that a number of these matters may be the subject of negotiation and litigation over many years. Litigation proceedings, including the various appeal procedures, often take many years to reach resolution, and out-of-court settlement discussions can also often be protracted.

The Group is in potential settlement discussions in a number of the disputes for which amounts have been provided and, based on its current assessment of the progress of these disputes, estimates that £138 million of the amount provided at 31 December 2017 will be settled within one year. At 31 December 2017, it was expected that £nil million (2016 – £nil) of the provision made for legal and other disputes will be reimbursed by third party insurers. For a discussion of legal issues, see Note 45, ‘Legal proceedings’.

Major restructuring programmes

In 2013, the Group initiated the Major Change restructuring programme focused on opportunities to simplify supply chain processes, build the Group’s capabilities in manufacturing and R&D and restructure the European Pharmaceuticals business.

The Pharmaceuticals restructuring programme, announced in October 2014, has been focused on rescaling commercial operations, global support functions and certain R&D/manufacturing operations across Pharmaceuticals. In addition, an integration restructuring programme was initiated in 2015, following the completion of the Novartis transaction, and the CEO Strategic Initiatives Programme was announced in July 2017. All of these restructuring and integration programmes are now reported together as one combined major restructuring programme.

Provisions for staff severance payments are made when management has made a formal decision to eliminate certain positions and this has been communicated to the groups of employees affected and appropriate consultation procedures completed, where appropriate. No provision is made for staff severance payments that are made immediately.

Pension augmentations arising from staff redundancies of £18 million (2016 – £23 million) have been charged during the year and then transferred to the pension obligations provision as shown in Note 28, ‘Pensions and other post-employment benefits’. Asset write-downs have been recognised as impairments of property, plant and equipment in Note 17, ‘Property, plant and equipment’. The majority of the amounts provided are expected to be utilised in the next two years.

Employee related provisions

Employee related provisions include obligations for certain medical benefits to disabled employees and their spouses in the US. At 31 December 2017, the provision for these benefits amounted to £108 million (2016 – £135 million). Other employee benefits reflect a variety of provisions for severance costs, jubilee awards and other long-service benefits.

Other provisions

Included in other provisions are insurance provisions of £6 million (2016 – £40 million), onerous property lease provisions of £38 million (2016 – £39 million) and a number of other provisions including vehicle insurance and regulatory matters.

XML

Other non-current liabilities

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Other non-current liabilities

30. Other non-current liabilities

	2017		2016
	£m		£m
Accruals and deferred income		104		66
Consumer Healthcare put option liability		—		7,420
Other payables		877		959
		981		8,445

XML

Net debt

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Net debt

31. Net debt

		2017			2016
	Listing exchange	£m			£m
Current assets:
Liquid investments			78			89
Cash and cash equivalents			3,833			4,897
			3,911			4,986
Short-term borrowings:
Commercial paper			(529	)		(1,094	)
Bank loans and overdrafts			(236	)		(332	)
Obligations under finance leases			(23	)		(23	)
1.50% US$ US Medium Term Note 2017	New York Stock Exchange		—			(1,612	)
5.625% € European Medium Term Note 2017	London Stock Exchange		—			(1,068	)
5.65% US$ US Medium Term Note 2018	New York Stock Exchange		(2,037	)		—
			(2,825	)		(4,129	)
Long-term borrowings:
5.65% US$ US Medium Term Note 2018	New York Stock Exchange		—			(2,216	)
0.625% € European Medium Term Note 2019	London Stock Exchange		(1,324	)		(1,276	)
0% € European Medium Term Note 2020	London Stock Exchange		(1,060	)		—
2.85% US$ US Medium Term Note 2022	New York Stock Exchange		(1,474	)		(1,603	)
2.8% US$ US Medium Term Note 2023	New York Stock Exchange		(919	)		(999	)
1.375% € European Medium Term Note 2024	London Stock Exchange		(876	)		(845	)
4.00% € European Medium Term Note 2025	London Stock Exchange		(659	)		(635	)
1% € European Medium Term Note 2026	London Stock Exchange		(617	)		—
3.375% £ European Medium Term Note 2027	London Stock Exchange		(593	)		(593	)
1.375% € European Medium Term Note 2029	London Stock Exchange		(439	)		—
5.25% £ European Medium Term Note 2033	London Stock Exchange		(986	)		(986	)
5.375% US$ US Medium Term Note 2034	London Stock Exchange		(368	)		(401	)
6.375% US$ US Medium Term Note 2038	New York Stock Exchange		(2,021	)		(2,199	)
6.375% £ European Medium Term Note 2039	London Stock Exchange		(695	)		(695	)
5.25% £ European Medium Term Note 2042	London Stock Exchange		(989	)		(988	)
4.2% US$ US Medium Term Note 2043	New York Stock Exchange		(363	)		(395	)
4.25% £ European Medium Term Note 2045	London Stock Exchange		(789	)		(789	)
Obligations under finance leases			(43	)		(41	)
Other long term borrowings			(49	)		—
			(14,264	)		(14,661	)
Net debt			(13,178	)		(13,804	)

Current assets

Liquid investments are classified as available-for-sale investments. At 31 December 2017, they included US Treasury Notes and other government bonds. The effective interest rate on liquid investments at 31 December 2017 was approximately 1.0% (2016 – approximately 0.7%). Liquid investment balances at 31 December 2017 earning interest at floating rates amount to £78 million (2016 – £89 million). Liquid investment balances at 31 December 2017 earning interest at fixed rates amount to £nil million (2016 – £nil).

The effective interest rate on cash and cash equivalents at 31 December 2017 was approximately 1.3% (2016 – approximately 1.3%). Cash and cash equivalents at 31 December 2017 earning interest at floating and fixed rates amount to £3,832 million and £1 million respectively (2016 – £4,584 million and £3 million).

GSK’s policy regarding the credit quality of cash and cash equivalents is referred to in Note 42, ‘Financial instruments and related disclosures’.

Short-term borrowings

GSK has a $10 billion (£7.4 billion) US commercial paper programme, of which $0.7 billion (£0.5 billion) was in issue at 31 December 2017 (2016 – $1.4 billion (£1.1 billion)). GSK also has £1.9 billion five year committed facilities and $2.5 billion (£1.9 billion) of 364 day committed facilities. The five-year committed facilities were agreed in September 2015 and were extended by one year to 2021 in September 2016. The 364 day committed facilities were agreed in August 2017. Liquid investments, cash and cash equivalents were as shown in the table on page 199.

The weighted average interest rate on commercial paper borrowings at 31 December 2017 was 1.53% (2016 – 0.88%).

The weighted average interest rate on current bank loans and overdrafts at 31 December 2017 was 4.65% (2016 – 3.47%).

The average effective pre-swap interest rate of notes classified as short term at 31 December 2017 was 5.92% (2016 – 3.18%).

Long-term borrowings

At the year-end, GSK had long-term borrowings of £14.3 billion (2016 – £14.7 billion) of which £10.3 billion (2016 – £11.1 billion) falls due in more than five years. The average effective pre-swap interest rate of all notes in issue at 31 December 2017 was approximately 3.6% (2016 – approximately 4.1%).

Long-term borrowings repayable after five years carry interest at effective rates between 1.07% and 6.66%, with repayment dates ranging from 2023 to 2045.

Pledged assets

The Group held pledged investments in US Treasury Notes with a par value of $105 million (£78 million), (2016 – $105 million (£85 million)) as security against irrevocable letters of credit issued on the Group’s behalf in respect of the Group’s self-insurance activity. Provisions in respect of self-insurance are included within the provisions for legal and other disputes discussed in Note 29, ‘Other provisions’. In addition, £20 million (2016 – £23 million) of assets included in Note 22, ‘Other non-current assets’, which do not form part of Net debt, were pledged as collateral against future rental payments under operating lease arrangements entered into by Human Genome Sciences, Inc. prior to its acquisition by the Group.

Finance lease obligations

	2017			2016
	£m			£m
Rental payments due within one year		25			25
Rental payments due between one and two years		29			23
Rental payments due between two and three years		9			12
Rental payments due between three and four years		3			7
Rental payments due between four and five years		2			—
Rental payments due after five years		10			—
Total future rental payments		78			67
Future finance charges		(12	)		(3	)
Total finance lease obligations		66			64

XML

Contingent liabilities

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Contingent liabilities

32. Contingent liabilities

At 31 December 2017, contingent liabilities, comprising guarantees, discounted bills and other items arising in the normal course of business, amounted to £434 million (2016 – £281 million). At 31 December 2017, £2 million (2016 – £1 million) of financial assets were pledged as collateral for contingent liabilities. Provision is made for the outcome of tax, legal and other disputes where it is both probable that the Group will suffer an outflow of funds and it is possible to make a reliable estimate of that outflow. At 31 December 2017, other than for those disputes where provision has been made, it was not possible to make a reliable estimate of the potential outflow of funds that might be required to settle disputes where the possibility of there being an outflow was more than remote. Descriptions of the significant tax, legal and other disputes to which the Group is a party are set out in Note 14, ‘Taxation’ and Note 45, ‘Legal proceedings’.

XML

Share capital and share premium account

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Share capital and share premium account

33. Share capital and share premium account

	Ordinary Shares of 25p each				Share premium
	Number		£m		£m
Share capital authorised
At 31 December 2015		10,000,000,000		2,500
At 31 December 2016		10,000,000,000		2,500
At 31 December 2017		10,000,000,000		2,500
Share capital issued and fully paid
At 1 January 2015		5,355,297,232		1,339		2,759
Issued under employee share schemes		6,010,415		1		72
At 31 December 2015		5,361,307,647		1,340		2,831
Issued under employee share schemes		7,008,415		2		87
Ordinary shares acquired by ESOP Trusts		—		—		36
At 31 December 2016		5,368,316,062		1,342		2,954
Issued under employee share schemes		4,237,758		1		55
Ordinary shares acquired by ESOP Trusts		—		—		10
At 31 December 2017		5,372,553,820		1,343		3,019

	31 December 2017		31 December 2016
	000		000
Number of shares issuable under employee share schemes		38,647		71,382
Number of unissued shares not under option		4,588,799		4,560,302

At 31 December 2017, of the issued share capital, 66,696,677 shares were held in the ESOP Trusts, 414,605,950 shares were held as Treasury shares and 4,891,251,193 shares were in free issue. All issued shares are fully paid. The nominal, carrying and market values of the shares held in the ESOP Trusts are disclosed in Note 43, ‘Employee share schemes’.

XML

Movements in equity

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Movements in equity

34. Movements in equity

Retained earnings and other reserves amounted to £(4,430) million at 31 December 2017 (2016 – £(3,172) million; 2015 – £943 million) of which £334 million (2016 – £329 million; 2015 – £283 million) relates to joint ventures and associated undertakings. The cumulative translation exchange in equity is as follows:

	Net translation exchange included in:
						Non-			Total
	Retained			Fair value		controlling			translation
	earnings			reserve		interests			exchange
	£m			£m		£m			£m
At 1 January 2015		(137	)		4		(117	)		(250	)
Exchange movements on overseas net assets		(624	)		6		8			(610	)
At 31 December 2015		(761	)		10		(109	)		(860	)
Exchange movements on overseas net assets		633			13		603			1,249
At 31 December 2016		(128	)		23		494			389
Exchange movements on overseas net assets		462			—		(149	)		313
Reclassification of exchange on liquidation or disposal of overseas subsidiaries		109			—		—			109
At 31 December 2017		443			23		345			811

The analysis of other comprehensive income by equity category is as follows:

							Non-
	Retained			Other			controlling
	earnings			reserves			interests			Total
2017	£m			£m			£m			£m
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges		462			—			—			462
Reclassification of exchange on liquidation or disposal of overseas subsidiaries		109			—			—			109
Fair value movements on available-for-sale investments		—			(14	)		—			(14	)
Reclassification of fair value movements on available-for-sale investments		—			(42	)		—			(42	)
Deferred tax on fair value movements on available-for-sale investments		—			47			—			47
Deferred tax reversed on reclassification of available for sale investments		—			(18	)		—			(18	)
Fair value movements on cash flow hedges		—			(10	)		—			(10	)
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests		—			—			(149	)		(149	)
Remeasurement gains on defined benefit plans		549			—			—			549
Tax on remeasurement gains in defined benefit plans		(221	)		—			—			(221	)
Other comprehensive income/(expense) for the year		899			(37	)		(149	)		713
							Non-
	Retained			Other			controlling
	earnings			reserves			interests			Total
2016	£m			£m			£m			£m
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges		633			13			—			646
Fair value movements on available-for-sale investments		—			251			—			251
Reclassification of fair value movements on available-for-sale investments		—			(245	)		—			(245	)
Deferred tax reversed on reclassification of available-for-sale investments		—			51			—			51
Reclassification of cash flow hedges to income statement		—			1			—			1
Fair value movements on cash flow hedges		—			2			—			2
Deferred tax on fair value movements on cash flow hedges		—			2			—			2
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests		—			—			603			603
Remeasurement losses on defined benefit plans		(475	)		—			—			(475	)
Tax on remeasurement losses in defined benefit plans		126			—			—			126
Other comprehensive income for the year		284			75			603			962

							Non-
	Retained			Other			controlling
	earnings			reserves			interests		Total
2015	£m			£m			£m		£m
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges		(624	)		6			—		(618	)
Fair value movements on available-for-sale investments		—			416			—		416
Deferred tax on fair value movements on available-for-sale investments		—			(91	)		—		(91	)
Reclassification of fair value movements on available-for-sale investments		—			(346	)		—		(346	)
Deferred tax reversed on reclassification of available-for-sale investments		—			36			—		36
Reclassification of cash flow hedges to income statement		—			2			—		2
Fair value movements on cash flow hedges		—			2			—		2
Share of other comprehensive expense of associates and joint ventures		(77	)		—			—		(77	)
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests		—			—			8		8
Remeasurement gains on defined benefit plans		261			—			—		261
Tax on remeasurement gains in defined benefit plans		(80	)		—			—		(80	)
Other comprehensive (expense)/income for the year		(520	)		25			8		(487	)

The analysis of other reserves is as follows:

	ESOP Trust			Fair value			Cash flow			Other
	shares			reserve			hedge reserve			reserves		Total
	£m			£m			£m			£m		£m
At 1 January 2015		(151	)		274			(13	)		2,129		2,239
Transferred to income and expense in the year on disposals		—			(356	)		2			—		(354	)
Transferred to income and expense in the year on impairments		—			10			—			—		10
Net fair value movement in the year		—			367			2			—		369
Ordinary shares acquired by ESOP Trusts		(99	)		—			—			—		(99	)
Write-down of shares held by ESOP Trusts		175			—			—			—		175
At 31 December 2015		(75	)		295			(9	)		2,129		2,340
Transferred to income and expense in the year on disposals		(16	)		(268	)		—			—		(284	)
Transferred to income and expense in the year on impairments		—			23			—			—		23
Net fair value movement in the year		—			330			6			—		336
Ordinary shares acquired by ESOP Trusts		(576	)		—			—			—		(576	)
Write-down of shares held by ESOP Trusts		381			—			—			—		381
At 31 December 2016		(286	)		380			(3	)		2,129		2,220
Transferred to income and expense in the year on disposals		22			(42	)		—			—		(20	)
Transferred to income and expense in the year on impairments		—			—			—			—		—
Net fair value movement in the year		—			(9	)		(8	)		—		(17	)
Ordinary shares acquired by ESOP Trusts		(656	)		—			—			—		(656	)
Write-down of shares held by ESOP Trusts		520			—			—			—		520
At 31 December 2017		(400	)		329			(11	)		2,129		2,047

Other reserves include various non-distributable merger and pre-merger reserves amounting to £1,849 million at 31 December 2017 (2016 – £1,849 million; 2015 – £1,849 million). Other reserves also include the capital redemption reserve created as a result of the share buy-back programme amounting to £280 million at 31 December 2017 (2016 – £280 million; 2015 – £280 million).

XML

Related party transactions

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Related party transactions

35. Related party transactions

At 31 December 2017, GSK owned 32 million shares or 31.4% of Innoviva Inc. which is a biopharmaceutical company listed on NASDAQ. GSK began recognising Innoviva as an associate on 1 September 2015. The royalties due from GSK to Innoviva in the year were £173 million (2016 – £108 million). At 31 December 2017, the balance payable by GSK to Innoviva was £53 million (2016 – £36 million).

At 31 December 2017, GSK held a 50% interest in Japan Vaccine Co. Ltd (JVC) through its subsidiary GlaxoSmithKline K.K. This joint venture with Daiichi Sankyo Co., Ltd is primarily responsible for the development and marketing of certain prophylactic vaccines in Japan. During 2017, GSK sold £41 million (2016 – £43 million) of its vaccine products into the joint venture. At 31 December 2017, the trading balance due to GSK from JVC was £11 million (2016 – £9 million) and the balance payable by GSK to JVC was £nil million (2016 – £nil). Loans of £7 million to JVC, £7 million to Medicxi Ventures I LP and £8 million to Index Ventures Life VI (Jersey) LP remained due to GSK at 31 December 2017.

The aggregate compensation of the Directors and CET is given in Note 9, ‘Employee costs’.

XML

Adjustments reconciling profit after tax to operating cash flows

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Adjustments reconciling profit after tax to operating cash flows

36. Adjustments reconciling profit after tax to operating cash flows

	2017			2016			2015
	£m			£m			£m
Profit after tax		2,169			1,062			8,372
Tax on profits		1,356			877			2,154
Share of after tax profits of associates and joint ventures		(13	)		(5	)		(14	)
Finance expense net of finance income		669			664			653
Depreciation		988			978			892
Amortisation of intangible assets		934			796			738
Impairment and assets written off		1,061			226			822
Profit on sale of businesses		(157	)		(5	)		(9,308	)
Profit on sale of intangible assets		(46	)		(178	)		(349	)
Profit on sale of investments in associates		(94	)		—			(843	)
Profit on sale of equity investments		(37	)		(254	)		(342	)
Changes in working capital:
(Increase)/decrease in inventories		(461	)		70			(111	)
(Increase)/decrease in trade receivables		(287	)		(188	)		98
Increase in trade payables		11			96			40
Decrease/(increase) in other receivables		74			381			(593	)
Contingent consideration paid (see Note 39)		(594	)		(358	)		(121	)
Other non-cash increase in contingent consideration liabilities		961			2,281			1,986
Increase in other payables		1,741			1,989			276
(Decrease)/increase in pension and other provisions		(255	)		(621	)		100
Share-based incentive plans		333			319			368
Fair value adjustments		—			(3	)		—
Other		(95	)		(21	)		(187	)
		6,089			7,044			(3,741	)
Cash generated from operations		8,258			8,106			4,631

XML

Reconciliation of net cash flow to movement in net debt

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Reconciliation of net cash flow to movement in net debt

37. Reconciliation of net cash flow to movement in net debt

	2017			2016			2015
	£m			£m			£m
Net debt at beginning of year		(13,804	)		(10,727	)		(14,377	)
(Decrease)/increase in cash and bank overdrafts		(905	)		(1,164	)		1,503
(Decrease)/increase in liquid investments		(4	)		—			2
Net increase in long-term loans		(2,233	)		—			—
Net repayment of/(increase in) short-term loans		3,200			(148	)		2,412
Net repayment of obligations under finance leases		23			18			25
Exchange adjustments		585			(1,781	)		(268	)
Other non-cash movements		(40	)		(2	)		(24	)
Movement in net debt		626			(3,077	)		3,650
Net debt at end of year		(13,178	)		(13,804	)		(10,727	)

	At 1 January									Profit			Reclass-									At 31 December
	2017			Exchange			Other			and loss			ifications			Disposals			Cash flow			2017
Analysis of changes in net debt	£m			£m			£m			£m			£m			£m			£m			£m
Liquid investments		89			(7	)		—			—			—			—			(4	)		78
Cash and cash equivalents		4,897			(106	)		—			—			—			(6	)		(952	)		3,833
Overdrafts		(292	)		6			—			—			—			—			53			(233	)
		4,605			(100	)		—			—			—			(6	)		(899	)		3,600
Debt due within one year:
Commercial paper		(1,094	)		37			—			—			—			—			528			(529	)
European and US Medium Term Notes		(2,680	)		121			—			—			(2,114	)		—			2,636			(2,037	)
Other		(63	)		2			(5	)		—			(19	)		—			59			(26	)
		(3,837	)		160			(5	)		—			(2,133	)		—			3,223			(2,592	)
Debt due after one year:
European and US Medium Term Notes		(14,620	)		530			4			(16	)		2,114			—			(2,233	)		(14,221	)
Other		(41	)		2			(23	)		—			19			—			—			(43	)
		(14,661	)		532			(19	)		(16	)		2,133			—			(2,233	)		(14,264	)
Net debt		(13,804	)		585			(24	)		(16	)		—			(6	)		87			(13,178	)
Analysis of changes in liabilities from financing activities
Debt due within one year		(3,837	)		160			(5	)		—			(2,133	)		—			3,223			(2,592	)
Debt due after one year		(14,661	)		532			(19	)		(16	)		2,133			—			(2,233	)		(14,264	)
Hedge of borrowings:
Derivative financial instruments		(38	)		—			37			5			—			—			(2	)		2
Other financing items		—			91			—			—			—			—			(91	)		—
Interest payable		(158	)		4			1			(731	)		(100	)		—			781			(203	)
Total liabilities from financing activities		(18,694	)		787			14			(742	)		(100	)		—			1,678			(17,057	)

For further information on significant changes in net debt see Note 31, ‘Net debt’.

XML

Acquisitions and disposals

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Acquisitions and disposals

38. Acquisitions and disposals

Details of the acquisition and disposal of significant subsidiaries and associates, joint ventures and other businesses are given below:

2017

Business acquisitions

There were no business acquisitions during 2017.

Business disposals

GSK made a number of small business disposals during the year for a net cash consideration of £342 million, including contingent consideration receivable of £86 million. The profit on disposal was determined as follows:

	Total
	£m
Consideration including currency forwards and purchase adjustments		342
Net assets sold:
Goodwill		(16	)
Intangible assets		(21	)
Property, plant and equipment		(18	)
Inventory		(11	)
Cash and cash equivalents		(6	)
Other net assets		(5	)
		(77	)
Transaction costs		(8	)
Reclassification of exchange from other comprehensive income		(100	)
Profit on disposal		157

Investment in associates and joint ventures

During the year, GSK made cash investments of £15 million into associates and joint ventures. In addition, GSK sold its holdings in two associates for £198 million in cash.

	Total
	£m
Cash consideration		198
Net book value of shares		(92	)
Reclassification of exchange from other comprehensive income		(7	)
Transaction costs		(5	)
Profit on disposal		94

Cash flows

				Associates			Associates
	Business			and JV			and JV
	disposals			investments			disposals
	£m			£m			£m
Cash consideration		256			(15	)		198
Net deferred consideration received		39			—			—
Cash and cash equivalents divested		(6	)		—			—
Transaction costs paid		(7	)		—			(2	)
Cash inflow		282			(15	)		196

2016

Business acquisitions

GSK completed two small business acquisitions during 2016.

Cash consideration of £24 million was paid in the year to acquire the HIV R&D preclinical and discovery stage portfolio from Bristol Myers Squibb. Further consideration, contingent on commercial milestones and future sales performance, may be due, and an initial estimate of £40 million was recognised for this contingent consideration. Intangible assets acquired were valued at £57 million and goodwill of £7 million was recognised.

GSK formed Galvani Bioelectronics Limited during the year and acquired intangible assets of £45 million and cash and cash equivalents of £41 million from Verily Life Sciences LLC in return for a 45% shareholding in Galvani Bioelectronics. The fair value of this shareholding was £47 million, and GSK also recognised a credit of £39 million in non-controlling interests representing Verily’s share of the net assets it contributed.

Business disposals

GSK also made a number of small business disposals in the year for net cash consideration of £72 million. In addition, deferred consideration receivable of £43 million was recognised.

Cash flows

	Business			Business
	acquisitions			disposals
	£m			£m
Cash consideration (paid)/received after purchase adjustments		(24	)		72
Cash and cash equivalents acquired		41			—
Cash inflow		17			72

In addition, GSK made cash investments of £11 million into associates and joint ventures.

2015

Business acquisitions

Novartis Consumer Healthcare and Vaccines businesses

The three-part inter-conditional transaction with Novartis AG involving the Consumer Healthcare, Vaccines and Oncology businesses completed on 2 March 2015.

GSK and Novartis have contributed their respective Consumer Healthcare businesses into a Consumer Healthcare Joint Venture in a non-cash transaction. GSK has an equity interest of 63.5% and majority control of the Joint Venture. In addition, GSK has acquired Novartis’ global Vaccines business (excluding influenza vaccines) for an initial cash consideration of $5.25 billion (£3.417 billion) with contingent consideration representing subsequent potential milestone payments of up to $1.8 billion (£1.2 billion) arising on the achievement of specified development targets and ongoing royalties based on the future sales performance of certain products, and so the total amount payable is unlimited. The first milestone of $450 million (£300 million) was paid on 26 March 2015.

Other business acquisitions

In addition, GSK completed one smaller Vaccines business acquisition for cash consideration of £120 million, net of cash acquired, and the fair value of existing investments of £15 million. This represented goodwill of £22 million and intangible assets of £124 million less other net liabilities of £11 million.

The fair values of the assets acquired in business combinations, including goodwill, are set out in the table below.

	Novartis
	Consumer			Novartis
	Healthcare			Vaccines
	business			business			Other
	£m			£m			£m
Net assets acquired:
Intangible assets		6,003			2,680			124
Property, plant and equipment		249			434			1
Inventory		257			347			—
Trade and other receivables		400			162			2
Other assets including cash and cash equivalents		304			283			19
Trade and other payables		(402	)		(107	)		(3	)
Deferred tax liabilities		(1,154	)		(78	)		(26	)
Other liabilities		(165	)		(299	)		—
		5,492			3,422			117
Non-controlling interest		(2,150	)		(19	)		—
Goodwill		774			576			22
		4,116			3,979			139
Consideration settled by shares in GSK Consumer Healthcare Holdings		4,116			—			—
Cash consideration paid after purchase adjustments		—			3,461			124
Fair value of equity investment disposal		—			—			15
Contingent consideration		—			594			—
Deferred tax on contingent consideration		—			(52	)		—
Loss on settlement of pre-existing relationships		—			(24	)		—
Total consideration		4,116			3,979			139

The non-controlling interest in the Consumer Healthcare Joint Venture, calculated applying the full goodwill method, represents Novartis’ share of the net assets it contributed to the Joint Venture together with attributable goodwill.

The goodwill in the businesses acquired represents the potential for further synergies arising from combining the acquired businesses with GSK’s existing businesses together with the value of the workforce acquired. The majority of the goodwill recognised is not expected to be deductible for tax purposes.

Total transaction costs recognised in 2014 and 2015 for the acquisitions from Novartis amounted to £102 million.

Between 2 March 2015 and 31 December 2015, turnover of £1,941 million arising from the Novartis Consumer Healthcare and Vaccines businesses was included in Group turnover. If the businesses had been acquired at the beginning of the year, it is estimated that Group turnover in 2015 would have been approximately £320 million higher. These businesses have been integrated into the Group’s existing activities and it is not practical to identify the impact on the Group profit in the period.

Business disposals

Oncology

GSK has divested its marketed Oncology business, related R&D activities and rights to its AKT inhibitor and also granted commercialisation partner rights for future oncology products to Novartis for consideration of $16 billion (£10,395 million) before purchase adjustments.

Other business disposals

GSK also made a number of small business disposals in the period for net cash consideration of £309 million. Profit on disposal of the businesses has been determined as follows:

	Oncology			Other
	£m			£m
Cash consideration including currency forwards and purchase adjustments		10,060			309
Net assets sold:
Goodwill		(497	)		(14	)
Intangible assets		(516	)		(107	)
Property, plant and equipment		—			(25	)
Inventory		—			(51	)
Cash		—			(5	)
Other net assets		—			(6	)
		(1,013	)		(208	)
Loss on currency forwards booked in 2014		299			—
Disposal costs		(118	)		(21	)
Profit on disposal		9,228			80

Associates and joint ventures

During the year, GSK made cash investments of £16 million into associates and joint ventures. In addition, in March 2015, GSK sold half of its shareholding in Aspen, representing 6.2% of the issued share capital of the company, for £571 million in cash. As a result of the sale, the Group was no longer considered to have the ability to exert significant influence over Aspen and the Group’s remaining investment was transferred from Investments in associates to Other investments.

	£m
Cash consideration		571
Net book value of shares		(143	)
Reclassification of exchange from other comprehensive income		(30	)
Transaction fees		(7	)
Other items		(5	)
Profit on disposal		386

Cash flows	Business acquisitions £m			Business disposals £m			Associates and JV disposals £m			Total £m
Cash consideration (paid)/received after purchase adjustments		(3,585	)		10,369			571			7,355
Cash and cash equivalents acquired/(divested)		404			(5	)		—			399
Deferred cash proceeds		—			(38	)		—			(38	)
Contingent consideration paid		(338	)		—			—			(338	)
Transaction costs and other		(22	)		(80	)		(7	)		(109	)
Cash (outflow)/inflow		(3,541	)		10,246			564			7,269

XML

Contingent consideration liabilities

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Contingent consideration liabilities

39. Contingent consideration liabilities

The consideration for certain acquisitions includes amounts contingent on future events such as development milestones or sales performance. The Group has provided for the fair value of this contingent consideration as follows:

	Shionogi- ViiV Healthcare £m			Novartis Vaccines £m			Other £m			Total £m
At 1 January 2015		1,684			—			40			1,724
Additions through business combinations		—			594			—			594
Remeasurement through income statement		1,874			111			1			1,986
Cash payments: operating cash flows		(121	)		—			—			(121	)
Cash payments: investing activities		(38	)		(300	)		—			(338	)
Other movements		10			—			—			10
At 31 December 2015		3,409			405			41			3,855
Additions through business combinations		154			—			40			194
Remeasurement through income statement		2,162			152			(33	)		2,281
Cash payments: operating cash flows		(351	)		(5	)		(2	)		(358	)
Cash payments: investing activities		(66	)		(7	)		—			(73	)
Other movements		(4	)		—			1			(3	)
At 31 December 2016		5,304			545			47			5,896
Remeasurement through income statement		909			53			(1	)		961
Cash payments: operating cash flows		(587	)		(7	)		—			(594	)
Cash payments: investing activities		(84	)		(7	)		—			(91	)
At 31 December 2017		5,542			584			46			6,172

Of the contingent consideration payable at 31 December 2017, £1,076 million (2016 – £561 million) is expected to be paid within one year. The contingent consideration payable in respect of the Novartis Vaccines business included a sales milestone of $450 million which was settled in January 2018.

The consideration payable for the acquisition of the Shionogi-ViiV Healthcare joint venture and the Novartis Vaccines business is expected to be paid over a number of years. As a result, the total estimated liabilities are discounted to their present values, shown above. The Shionogi-ViiV Healthcare contingent consideration liability is discounted at 8.5% and the Novartis Vaccines contingent consideration liability is discounted partly at 8% and partly at 9%.

The Shionogi-ViiV Healthcare contingent consideration liability is calculated based on the forecast sales performance of specified products, principally dolutegravir, over the life of those products.

The table below shows on an indicative basis the income statement and balance sheet sensitivity to reasonably possible changes in key inputs to the valuations of the contingent consideration liabilities.

Increase/(decrease) in financial liability and loss/(gain) in Income statement	Shionogi- ViiV Healthcare £m			Novartis Vaccines £m
10% increase in sales forecasts		535			56
10% decrease in sales forecasts		(535	)		(55	)
1% increase in discount rate		(228	)		(18	)
1% decrease in discount rate		245			20
5% increase in probability of milestone success					6
5% decrease in probability of milestone success					(6	)
10 cent appreciation of US Dollar		329			17
10 cent depreciation of US Dollar		(284	)		(15	)
10 cent appreciation of Euro		95			25
10 cent depreciation of Euro		(80	)		(21	)

An explanation of the accounting for ViiV Healthcare is set out on page 59.

XML

Non-controlling interests

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Non-controlling interests

40. Non-controlling interests

The Group has two subgroups that have material non-controlling interests, ViiV Healthcare Limited and its subsidiaries and GSK Consumer Healthcare Holdings Limited and its subsidiaries. Summarised financial information in respect of the ViiV Healthcare group and GSK Consumer Healthcare Joint Venture is set out below:

ViiV Healthcare

	2017 £m		2016 £m			2015 £m
Turnover		4,269		3,527			2,330
Profit/(loss) after taxation		825		(1,249	)		(1,426	)
Other comprehensive income		20		36			7
Total comprehensive income/(expense)		845		(1,213	)		(1,419	)

	2017 £m			2016 £m
Non-current assets		2,736			3,064
Current assets		2,533			2,357
Total assets		5,269			5,421
Current liabilities		(2,409	)		(1,977	)
Non-current liabilities		(8,011	)		(7,983	)
Total liabilities		(10,420	)		(9,960	)
Net liabilities		(5,151	)		(4,539	)

	2017 £m			2016 £m			2015 £m
Net cash inflow from operating activities		2,132			1,750			1,097
Net cash outflow from investing activities		(207	)		(326	)		(63	)
Net cash outflow from financing activities		(1,820	)		(1,023	)		(814	)
Increase in cash and bank overdrafts in the year		105			401			220

The above financial information relates to the ViiV Healthcare group on a stand-alone basis, before the impact of Group-related adjustments, primarily related to the recognition of preferential dividends. The profit after taxation of £825 million (2016 – loss after taxation of £1,249 million; 2015 – loss after taxation of £1,426 million) is stated after charging preferential dividends payable to GSK, Shionogi and Pfizer and after a charge of £909 million (2016 – £2,186 million; 2015 – £1,874 million) for remeasurement of the contingent consideration payable for the acquisition of the former Shionogi-ViiV Healthcare joint venture. This consideration is expected to be paid over a number of years.

The following amounts attributable to the ViiV Healthcare group are included in GSK’s Consolidated statement of comprehensive income, Consolidated statement of changes in equity and Consolidated balance sheet:

	2017 £m			2016 £m			2015 £m
Total comprehensive income/(expense) for the year attributable to non-controlling interests		187			(83	)		(143	)
Dividends paid to non-controlling interests		316			152			163
Non-controlling interests in the Consolidated balance sheet		(476	)		(353	)

Consumer Healthcare Joint Venture

	2017 £m			2016 £m		2015 £m
Turnover		7,003			6,530		4,627
Profit/(loss) after taxation		1,211			660		(39	)
Other comprehensive income		(387	)		1,640		72
Total comprehensive income		824			2,300		33

	2017 £m			2016 £m
Non-current assets		12,771			13,315
Current assets		3,282			3,996
Total assets		16,053			17,311
Current liabilities		(2,675	)		(3,060	)
Non-current liabilities		(1,537	)		(2,062	)
Total liabilities		(4,212	)		(5,122	)
Net assets		11,841			12,189

	2017 £m			2016 £m			2015 £m
Net cash inflow from operating activities		883			1,496			277
Net cash inflow/(outflow) from investing activities		270			(537	)		(691	)
Net cash outflow from financing activities		(1,194	)		(980	)		(42	)
Decrease in cash and bank overdrafts in the year		(41	)		(21	)		(456	)

The above financial information relates to the Consumer Healthcare Joint Venture on a stand-alone basis, before the impact of Group-related adjustments but after major restructuring charges.

The following amounts attributable to the Consumer Healthcare Joint Venture are included in GSK’s Consolidated statement of comprehensive income, Consolidated statement of changes in equity and Consolidated balance sheet:

	2017		2016		2015
	£m		£m		£m
Total comprehensive income for the year attributable to non-controlling interests		296		730		14
Dividends paid to non-controlling interests		420		346		—
Non-controlling interests in the Consolidated balance sheet		3,631		3,755

XML

Commitments

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Commitments

41. Commitments

	2017		2016
Contractual obligations and commitments	£m		£m
Contracted for but not provided in the financial statements:
Intangible assets		5,254		7,199
Property, plant and equipment		584		496
Investments		107		166
Purchase commitments		346		52
Pensions		738		874
Other commitments		38		143
Interest on loans		8,510		9,410
Finance lease charges		12		3
		15,589		18,343

The commitments related to intangible assets include milestone payments, which are dependent on successful clinical development or on meeting specified sales targets, and which represent the maximum that would be paid if all milestones, however unlikely, are achieved. The amounts are not risk-adjusted or discounted. The decrease in intangible commitments in 2017 is attributable to amendments made to the agreement with Adaptimmune Therapeutics plc and reduction in commitments to third parties such as Ionis Pharmaceuticals, Inc.

In 2016, GSK reached an agreement with the trustees of the UK pension schemes to make additional contributions to eliminate the pension deficit identified at the 31 December 2014 actuarial funding valuation. A payment of £123 million is due in 2018 and each subsequent year up to, and including 2023. The table above includes this commitment, but excludes the normal ongoing annual funding requirement in the UK of approximately £130 million.

The Group also has other commitments which principally relate to revenue payments to be made under licences and other alliances.

Commitments in respect of future interest payable on loans are disclosed before taking into account the effect of interest rate swaps.

Commitments under non-cancellable operating leases are disclosed below. £117 million (2016 – £186 million) is provided against these commitments on the Group’s balance sheet.

	2017		2016
Commitments under non-cancellable operating leases	£m		£m
Rental payments due within one year		186		153
Rental payments due between one and two years		149		129
Rental payments due between two and three years		122		94
Rental payments due between three and four years		107		74
Rental payments due between four and five years		94		66
Rental payments due after five years		387		324
Total commitments under non-cancellable operating leases		1,045		840

XML

Financial instruments and related disclosures

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Financial instruments and related disclosures

42. Financial instruments and related disclosures

GSK uses a variety of financial instruments to finance its operations and derivative financial instruments to manage market risks from these operations. These derivatives, principally comprising interest rate swaps, foreign exchange forward contracts and swaps, are used to swap borrowings and liquid assets into currencies required for Group purposes and to manage exposure to financial risks from changes in foreign exchange rates and interest rates.

GSK does not hold or issue derivatives for speculative purposes and GSK’s Treasury policies specifically prohibit such activity. All transactions in financial instruments are undertaken to manage the risks arising from underlying business activities.

Capital management

GSK’s financial strategy supports the Group’s strategic priorities and is regularly reviewed by the Board. GSK manages the capital structure of the Group through an appropriate mix of debt and equity.

The capital structure of the Group consists of net debt of £13.2 billion (see Note 31, ‘Net debt’) and total equity, including that provided by non-controlling interests, of £3.5 billion (see ‘Consolidated statement of changes in equity’ on page 160). Total capital, including that provided by non-controlling interests, is £16.7 billion.

Our long-term credit rating with Standard and Poor’s is A+ (stable outlook) and with Moody’s Investor Services (‘Moody’s’) it is A2 (stable outlook). The Group’s short-term credit ratings are A-1 and P-1 with Standard and Poor’s and Moody’s respectively.

Liquidity risk management

GSK’s policy is to borrow centrally in order to meet anticipated funding requirements. The strategy is to diversify liquidity sources using a range of facilities and to maintain broad access to financial markets.

At 31 December 2017, GSK had £2.8 billion of borrowings repayable within one year and held £3.9 billion of cash and cash equivalents and liquid investments of which £2.5 billion was held centrally. GSK has access to short-term finance under a $10 billion (£7.4 billion) US commercial paper programme; $0.7 billion (£0.5 billion) was in issue at 31 December 2017 (2016 – $1.4 billion). GSK also has £1.9 billion five year committed facilities and $2.5 billion (£1.9 billion) of 364 day committed facilities. The five-year committed facilities were agreed in September 2015 and were extended by one year to 2021 in September 2016. The 364 day committed facilities were agreed in August 2017. These facilities were undrawn at 31 December 2017. GSK considers this level of committed facilities to be adequate, given current liquidity requirements.

GSK has a £15 billion European Medium Term Note programme and at 31 December 2017, £9.0 billion of notes were in issue under this programme. The Group also had $9.7 billion (£7.2 billion) of notes in issue at 31 December 2017 under a US shelf registration. GSK’s borrowings mature at dates between 2018 and 2045.

The put options owned by minority interest partners in ViiV Healthcare and the Consumer Healthcare JV business are both now exercisable. In reviewing liquidity requirements GSK considers that sufficient financing options are available should the put options be exercised.

Market risk

Interest rate risk management

GSK’s objective is to minimise the effective net interest cost and to balance the mix of debt at fixed and floating interest rates over time. The policy on interest rate risk management limits the amount of floating interest payments to a prescribed percentage of operating profit.

Foreign exchange risk management

Foreign currency transaction exposures arising on external trade flows are not normally hedged. Foreign currency transaction exposures arising on internal trade flows are selectively hedged. The Group’s objective is to minimise the exposure of overseas operating subsidiaries to transaction risk by matching local currency income with local currency costs where possible. GSK’s internal trading transactions are matched centrally and inter-company payment terms are managed to reduce foreign currency risk. Foreign currency cash flows can be hedged selectively including hedges of the foreign exchange risk arising from acquisitions and disposals of assets. Where possible, GSK manages the cash surpluses or borrowing requirements of subsidiary companies centrally using forward contracts to hedge future repayments back into the originating currency.

In order to reduce foreign currency translation exposure, the Group seeks to denominate borrowings in the currencies of our principal assets and cash flows. These are primarily denominated in US Dollars, Euros and Sterling. Borrowings can be swapped into other currencies as required.

Borrowings denominated in, or swapped into, foreign currencies that match investments in overseas Group assets may be treated as a hedge against the relevant assets. Forward contracts in major currencies are also used to reduce exposure to the Group’s investment in overseas assets (see ‘Net investment hedges’ section of this note for further details).

Credit risk

The Group considers its maximum credit risk at 31 December 2017 to be £9,988 million (31 December 2016 – £11,002 million) which is the total of the Group’s financial assets with the exception of ’Other investments’ (comprising equity investments) which bear equity risk rather than credit risk. See page 216 for details on the Group’s total financial assets. At 31 December 2017, GSK’s greatest concentrations of credit risk were £0.5 billion with Citibank (A/A1) and £0.5 billion with one US wholesaler (BBB+/Baa2) (2016 – £0.9 billion with Citibank (A/A1)).

Treasury-related credit risk

GSK sets global counterparty limits for each of GSK’s banking and investment counterparties based on long-term credit ratings from Moody’s and Standard and Poor’s. Usage of these limits is monitored daily.

GSK actively manages its exposure to credit risk, reducing surplus cash balances wherever possible. This is part of GSK’s strategy to regionalise cash management and to concentrate cash centrally as much as possible. The table below sets out the credit exposure to counterparties by rating for liquid investments, cash and cash equivalents and derivatives. The gross asset position on each derivative contract is considered for the purpose of this table, although, under ISDA agreements, the amount at risk is the net position with each counterparty. Table (e) on page 220 sets out the Group’s financial assets and liabilities on an offset basis.

At 31 December 2017, £45 million of cash is categorised as held with unrated or sub-investment grade rated counterparties (lower then BBB-/Baa3) of which £32 million is cash in transit. The remaining exposure is concentrated in overseas banks used for local cash management or investment purposes, including £7 million in Nigeria held with United Bank for Africa, Zenith Bank and Stanbic IBTC Bank and First Bank of Nigeria and £2 million with BTV in Austria. Of the £80 million of bank balances and deposits held with BBB/Baa rated counterparties, £27 million was held with BBB-/ Baa3 rated counterparties, including balances or deposits of £17 million with HDFC Bank in India and £10 million with State Bank of India. These banks are used for local investment purposes.

2017	AAA/Aaa £m		AA/Aa £m		A/A £m		BBB/Baa £m		BB+/Ba1 and below /unrated £m		Total £m
Bank balances and deposits		—		423		1,167		80		45		1,715
US Treasury and Treasury repo only money market funds		1,715		—		—		—		—		1,715
Liquidity funds		403		—		—		—		—		403
Government securities		—		77		—		1		—		78
3rd party financial derivatives		—		26		42		—		—		68
Total		2,118		526		1,209		81		45		3,979
2016	AAA/Aaa £m		AA/Aa £m		A/A £m		BBB/Baa £m		BB+/Ba1 and below /unrated £m		Total £m
Bank balances and deposits		—		542		1,560		388		93		2,583
US Treasury and Treasury repo only money market funds		2,248		—		—		—		—		2,248
Liquidity funds		66		—		—		—		—		66
Government securities		—		85		—		4		—		89
3rd party financial derivatives		—		70		86		—		—		156
Total		2,314		697		1,646		392		93		5,142

Credit ratings are assigned by Standard and Poor’s and Moody’s respectively. Where the opinions of the two rating agencies differ, GSK assigns the lower rating of the two to the counterparty. Where local rating agency or Fitch data is the only source available, the ratings are converted to global ratings equivalent to those of Standard and Poor’s or Moody’s using published conversion tables.

GSK’s centrally managed cash reserves amounted to £2.5 billion at 31 December 2017, all available within three months. This includes £1.7 billion centrally managed cash held by ViiV Healthcare, a 78.3% owned subsidiary. The Group has invested centrally managed liquid assets in bank deposits, Aaa/AAA rated US Treasury and Treasury repo only money market funds and Aaa/AAA rated liquidity funds.

Wholesale and retail credit risk

Outside the US, no customer accounts for more than 5% of the Group’s trade receivables balance.

In the US, in line with other pharmaceutical companies, the Group sells its products through a small number of wholesalers in addition to hospitals, pharmacies, physicians and other groups. Sales to the three largest wholesalers amounted to approximately 83% of the sales of the US Pharmaceuticals and Vaccines businesses in 2017. At 31 December 2017, the Group had trade receivables due from these three wholesalers totalling £1,265 million (2016 – £1,323 million). The Group is exposed to a concentration of credit risk in respect of these wholesalers such that, if one or more of them encounters financial difficulty, it could materially and adversely affect the Group’s financial results.

The Group’s credit risk monitoring activities relating to these wholesalers include a review of their quarterly financial information and Standard & Poor’s credit ratings, development of GSK internal risk ratings, and establishment and periodic review of credit limits. However, the Group believes there is no further credit risk provision required in excess of the normal provision for bad and doubtful debts (see Note 24, ‘Trade and other receivables’).

Fair value of financial assets and liabilities

The table on page 216 presents the carrying amounts and the fair values of the Group’s financial assets and liabilities at 31 December 2017 and 31 December 2016.

The fair values of the financial assets and liabilities are included at the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

The following methods and assumptions were used to estimate the fair values:

• Cash and cash equivalents – approximates to the carrying amount

• Liquid investments – based on quoted market prices or calculated based on observable inputs in the case of marketable securities; based on principal amounts in the case of non-marketable securities because of their short repricing periods

• Other investments – equity investments traded in an active market determined by reference to the relevant stock exchange quoted bid price; other equity investments determined by reference to the current market value of similar instruments or by reference to the discounted cash flows of the underlying net assets

• Short-term loans, overdrafts and commercial paper – approximates to the carrying amount because of the short maturity of these instruments

• Long-term loans – based on quoted market prices in the case of European and US Medium term notes and other fixed rate borrowings (a Level 1 fair value measurement); approximates to the carrying amount in the case of floating rate bank loans and other loans

• Contingent consideration for business acquisitions – based on present values of expected future cash flows

• Interest rate swaps, foreign exchange forward contracts, swaps and options – based on the present value of contractual cash flows or option valuation models using market sourced data (exchange rates or interest rates) at the balance sheet date

• Receivables and payables, including put options – approximates to the carrying amount

• Company-owned life insurance policies – based on cash surrender value

• Lease obligations – approximates to the carrying amount.

Fair value of investments in GSK shares

At 31 December 2017, the Employee Share Ownership Plan (ESOP) Trusts held GSK shares with a carrying value of £400 million (2016 – £286 million) and a fair value of £882 million (2016 – £667 million) based on quoted market price. The shares are held by the ESOP Trusts to satisfy future exercises of options and awards under employee incentive schemes. In 2017, the carrying value, which is the lower of cost or expected proceeds, of these shares has been recognised as a deduction from other reserves. At 31 December 2017, GSK held Treasury shares at a cost of £5,800 million (2016 – £6,451 million) which has been deducted from retained earnings.

	2017								2016
	Notes		Carrying value £m			Fair value £m			Carrying value £m			Fair value £m
Available-for-sale investments:
Liquid investments (Government bonds)		a		78			78			89			89
Other investments		a		918			918			985			985
Loans and receivables:
Cash and cash equivalents				3,833			3,833			4,897			4,897
Trade and other receivables and Other non-current assets in scope of IAS 39		b		5,495			5,495			5,499			5,499
Financial assets at fair value through profit or loss:
Trade and other receivables and Other non-current assets in scope of IAS 39		a,b		506			506			361			361
Derivatives designated as at fair value through profit or loss		a,d,e		5			5			23			23
Derivatives classified as held for trading under IAS 39		a,d,e		71			71			133			133
Total financial assets				10,906			10,906			11,987			11,987
Financial liabilities measured at amortised cost:
Borrowings excluding obligations under finance leases:
– bonds in a designated hedging relationship		d		(4,315	)		(4,405	)		(3,189	)		(3,335	)
– other bonds				(11,894	)		(14,743	)		(14,111	)		(16,996	)
– bank loans and overdrafts				(236	)		(236	)		(332	)		(332	)
– commercial paper				(529	)		(529	)		(1,094	)		(1,094	)
– other borrowings				(49	)		(49	)		—			—
Total borrowings excluding obligations under finance leases		f		(17,023	)		(19,962	)		(18,726	)		(21,757	)
Obligations under finance leases				(66	)		(66	)		(64	)		(64	)
Total borrowings				(17,089	)		(20,028	)		(18,790	)		(21,821	)
Trade and other payables, Other provisions and certain
Other non-current liabilities in scope of IAS 39		c		(20,325	)		(20,325	)		(18,713	)		(18,713	)
Financial liabilities at fair value through profit or loss:
Contingent consideration liabilities		a,c		(6,172	)		(6,172	)		(5,896	)		(5,896	)
Derivatives designated as at fair value through profit or loss		a,d,e		(26	)		(26	)		(92	)		(92	)
Derivatives classified as held for trading under IAS 39		a,d,e		(48	)		(48	)		(102	)		(102	)
Total financial liabilities				(43,660	)		(46,599	)		(43,593	)		(46,624	)
Net financial assets and financial liabilities				(32,754	)		(35,693	)		(31,606	)		(34,637	)

The valuation methodology used to measure fair value in the above table is described and categorised on page 215. Trade and other receivables, Other non-current assets, Trade and other payables, Other provisions, Other non-current liabilities and Contingent consideration liabilities are reconciled to the relevant Notes on page 218.

(a) Financial instruments held at fair value

The following tables categorise the Group’s financial assets and liabilities held at fair value by the valuation methodology applied in determining their fair value. Where possible, quoted prices in active markets are used (Level 1). Where such prices are not available, the asset or liability is classified as Level 2, provided all significant inputs to the valuation model used are based on observable market data. If one or more of the significant inputs to the valuation model is not based on observable market data, the instrument is classified as Level 3. Other investments classified as Level 3 in the tables below comprise equity investments in unlisted entities with which the Group has entered into research collaborations and also investments in emerging life science companies.

	Level 1		Level 2			Level 3			Total
At 31 December 2017	£m		£m			£m			£m
Financial assets at fair value
Available–for–sale financial assets:
Liquid investments		77		1			—			78
Other investments		535		—			383			918
Other non-current assets		—		—			38			38
Financial assets at fair value through profit or loss:
Other non-current assets		—		382			44			426
Trade and other receivables		—		—			42			42
Derivatives designated as at fair value through profit or loss		—		5			—			5
Derivatives classified as held for trading under IAS 39		—		62			9			71
		612		450			516			1,578
Financial liabilities at fair value
Financial liabilities at fair value through profit or loss:
Contingent consideration liabilities		—		—			(6,172	)		(6,172	)
Derivatives designated as at fair value through profit or loss		—		(26	)		—			(26	)
Derivatives classified as held for trading under IAS 39		—		(47	)		(1	)		(48	)
		—		(73	)		(6,173	)		(6,246	)
	Level 1		Level 2			Level 3			Total
At 31 December 2016	£m		£m			£m			£m
Financial assets at fair value
Available–for–sale financial assets:
Liquid investments		84		5			—			89
Other investments		580		—			405			985
Other non-current assets		—		—			6			6
Financial assets at fair value through profit or loss:
Other non-current assets		—		355			—			355
Derivatives designated as at fair value through profit or loss		—		23			—			23
Derivatives classified as held for trading under IAS 39		—		133			—			133
		664		516			411			1,591
Financial liabilities at fair value
Financial liabilities at fair value through profit or loss:
Contingent consideration liabilities		—		—			(5,896	)		(5,896	)
Derivatives designated as at fair value through profit or loss		—		(92	)		—			(92	)
Derivatives classified as held for trading under IAS 39		—		(101	)		(1	)		(102	)
		—		(193	)		(5,897	)		(6,090	)

Movements in the year for financial instruments measured using Level 3 valuation methods are presented below:

	2017			2016
	£m			£m
At 1 January		(5,486	)		(3,582	)
Net losses recognised in the income statement		(970	)		(2,283	)
Net gains recognised in other comprehensive income		22			29
Contingent consideration for businesses divested/acquired during the year		80			(194	)
Payment of contingent consideration liabilities		685			431
Additions		117			81
Disposals		(52	)		(15	)
Transfers from Level 3		(24	)		(11	)
Exchange		(29	)		58
At 31 December		(5,657	)		(5,486	)

The net losses of £970 million (2016 – £2,283 million) attributable to Level 3 financial instruments which were recognised in the income statement were all attributable to financial instruments which were held at the end of the year. Losses of £971 million (2016 – £2,283 million) were reported in Other operating income and income of £1 million (2016 – £nil) was recorded in Finance income. £909 million (2016 – £2,162 million) arose from remeasurement of the contingent consideration payable for the acquisition of the former Shionogi-ViiV Healthcare joint venture and £53 million (2016 – £152 million) arose from remeasurement of the contingent consideration payable on the acquisition in 2015 of the Novartis Vaccines business. Net gains of £22 million (2016 – £29 million) attributable to Level 3 financial instruments reported in Other comprehensive income as Fair value movements on available-for-sale investments included net losses of £6 million (2016 – net gains of £21 million) in respect of financial instruments held at the end of the year.

Financial liabilities measured using Level 3 valuation methods at 31 December included £5,542 million (2016 – £5,304 million) in respect of contingent consideration payable for the acquisition in 2012 of the former Shionogi-ViiV Healthcare joint venture. This consideration is expected to be paid over a number of years and will vary in line with the future performance of specified products and movements in certain foreign currencies. They also included £584 million (2016 – £545 million) in respect of contingent consideration for the acquisition in 2015 of the Novartis Vaccines business. This consideration is expected to be paid over a number of years and will vary in line with the future performance of specified products, the achievement of certain milestone targets and movements in certain foreign currencies. Sensitivity analysis on these balances is provided in Note 39, ‘Contingent consideration liabilities’.

(b) Trade and other receivables and Other non-current assets in scope of IAS 39

The following table reconciles financial instruments within Trade and other receivables and Other non-current assets which fall within the scope of IAS 39 to the relevant balance sheet amounts. The financial assets are predominantly non-interest earning. Financial instruments within the Other non-current assets balance include company-owned life insurance policies. Non-financial instruments include tax receivables, pension surplus balances and prepayments, which are outside the scope of IAS 39.

	2017										2016
	At fair value through profit or loss £m		Loans and receivables £m		Financial instruments £m		Non- financial instruments £m		Total £m		At fair value through profit or loss £m		Loans and receivables £m		Financial instruments £m		Non- financial instruments £m		Total £m
Trade and other receivables (Note 24)		42		5,148		5,190		810		6,000		—		5,135		5,135		891		6,026
Other non-current assets (Note 22)		464		347		811		602		1,413		361		364		725		474		1,199
		506		5,495		6,001		1,412		7,413		361		5,499		5,860		1,365		7,225

The following table shows the ageing of such financial assets which are past due and for which no provision for bad or doubtful debts has been made:

	2017 £m		2016 £m
Past due by 1–30 days		142		137
Past due by 31–90 days		70		178
Past due by 91–180 days		64		55
Past due by 181–365 days		27		53
Past due by more than 365 days		108		98
		411		521

(c) Trade and other payables, Other provisions, Other non-current liabilities and Contingent consideration liabilities in scope of IAS 39

The following table reconciles financial instruments within Trade and other payables, Other provisions, Other non-current liabilities and Contingent consideration liabilities which fall within the scope of IAS 39 to the relevant balance sheet amounts. The financial liabilities are predominantly non-interest bearing. Accrued wages and salaries are included within financial liabilities. Non-financial instruments includes payments on account, tax and social security payables and provisions which do not arise from contractual obligations to deliver cash or another financial asset, which are outside the scope of IAS 39.

	2017															2016
	At fair value															At fair value
	through			Other			Financial			Non-financial						through			Other			Financial			Non-financial
	profit or loss			liabilities			instruments			instruments			Total			profit or loss			liabilities			instruments			instruments			Total
	£m			£m			£m			£m			£m			£m			£m			£m			£m			£m
Trade and other payables (Note 27)		—			(20,129	)		(20,129	)		(841	)		(20,970	)		—			(11,041	)		(11,041	)		(923	)		(11,964	)
Other provisions (Note 29)		—			(117	)		(117	)		(1,148	)		(1,265	)		—			(113	)		(113	)		(1,387	)		(1,500	)
Other non-current liabilities (Note 30)		—			(79	)		(79	)		(902	)		(981	)		—			(7,559	)		(7,559	)		(886	)		(8,445	)
Contingent consideration liabilities (Note 39)		(6,172	)		—			(6,172	)		—			(6,172	)		(5,896	)		—			(5,896	)		—			(5,896	)
		(6,172	)		(20,325	)		(26,497	)		(2,891	)		(29,388	)		(5,896	)		(18,713	)		(24,609	)		(3,196	)		(27,805	)

(d) Derivative financial instruments and hedging programmes

The following table sets out the fair values of derivatives held by GSK. All the derivative liabilities and £68 million (2016 – £156 million) of the derivative assets have a maturity of less than one year.

	2017 Fair value					2016 Fair value
	Assets £m		Liabilities £m			Assets £m		Liabilities £m
Net investment hedges – Foreign exchange contracts (principal amount – £6,333 million (2016 – £5,362 million))		5		(25	)		18		(92	)
Cash flow hedges – Foreign exchange contracts (principal amount – £38 million (2016 – £170 million))		—		(1	)		5		—
Derivatives designated as at fair value through profit or loss		5		(26	)		23		(92	)
Foreign exchange contracts (principal amount – £14,449 million (2016 – £14,943 million))		62		(47	)		133		(99	)
Embedded and other derivatives		9		(1	)		—		(3	)
Derivatives classified as held for trading under IAS 39		71		(48	)		133		(102	)
Total derivative instruments		76		(74	)		156		(194	)

Foreign exchange contracts classified as held for trading under IAS 39

The principal amount on foreign exchange contracts is the absolute total of outstanding positions at the balance sheet date. The Group’s foreign exchange contracts are for periods of 12 months or less. At 31 December 2017, the Group held outstanding foreign exchange contracts with a net asset fair value of £15 million (£62 million asset less £47 million liability). At 31 December 2016, the fair value was £34 million net asset (£133 million asset less £99 million liability).

The overall decrease in the net asset fair value has been due to the weakening of Sterling against the Euro in 2017 and the strengthening of Sterling against the US Dollar which has impacted on the portion of the hedging portfolio that is not in a designated accounting hedge. Fair value movements are taken to the income statement in the period to offset the exchange gains and losses on the related underlying balances.

Fair value hedges

At 31 December 2017, the Group had no designated fair value hedges.

Net investment hedges

During the year, certain foreign exchange contracts were designated as net investment hedges in respect of the foreign currency translation risk arising on consolidation of the Group’s net investment in its European (Euro) foreign operations as shown in the table above.

The carrying value of bonds on page 216 includes £4,315 million (2016 – £3,189 million) that are designated as hedging instruments in net investment hedges.

Cash flow hedges

During 2017, the Group entered into forward foreign exchange contracts which have been designated as cash flow hedges. These are hedging the foreign exchange exposure arising on Euro denominated coupon payments relating to notes issued under the Group’s European Medium Term Note programme and a number of highly probable forecast transactions denominated in US Dollars.

In addition, the Group carries a balance in reserves that arose from pre-hedging fluctuations in long-term interest rates when pricing bonds issued in prior years. The balance is reclassified to finance costs over the life of these bonds.

(e) Offsetting of financial assets and liabilities

Financial assets and liabilities are offset and the net amount reported in the balance sheet where there is a legally enforceable right to offset the recognised amounts, and there is an intention to settle on a net basis or realise the asset and settle the liability simultaneously. There are also arrangements that do not meet the criteria for offsetting but still allow for the related amounts to be offset in certain circumstances, such as bankruptcy or the termination of a contract.

The following tables set out the financial assets and liabilities that are offset, or subject to enforceable master netting arrangements and other similar agreements but not offset, as at 31 December 2017 and 31 December 2016. The column ‘Net amount’ shows the impact on the Group’s balance sheet if all offset rights were exercised.

At 31 December 2017	Gross financial assets/ (liabilities) £m			Financial (liabilities)/ assets offset £m			Net financial assets/ (liabilities) £m			Related amounts not offset £m			Net amount £m
Financial assets
Trade and other receivables		5,191			(1	)		5,190			(31	)		5,159
Derivative financial instruments		76			—			76			(64	)		12
Financial liabilities
Trade and other payables		(20,130	)		1			(20,129	)		31			(20,098	)
Derivative financial instruments		(74	)		—			(74	)		64			(10	)
At 31 December 2016	Gross financial assets/ (liabilities) £m			Financial (liabilities)/ assets offset £m			Net financial assets/ (liabilities) £m			Related amounts not offset £m			Net balance £m
Financial assets
Trade and other receivables		5,136			(1	)		5,135			(29	)		5,106
Derivative financial instruments		156			—			156			(117	)		39
Financial liabilities
Trade and other payables		(11,042	)		1			(11,041	)		29			(11,012	)
Derivative financial instruments		(194	)		—			(194	)		117			(77	)

Amounts which do not meet the criteria for offsetting on the balance sheet but could be settled net in certain circumstances principally relate to derivative transactions under ISDA (International Swaps and Derivatives Association) agreements where each party has the option to settle amounts on a net basis in the event of default of the other party. As there is presently not a legally enforceable right of offset, these amounts have not been offset in the balance sheet, but have been presented separately in the table above.

(f) Debt interest rate repricing table

The following table sets out the exposure of the Group to interest rates on debt, including commercial paper. The maturity analysis of fixed rate debt is stated by contractual maturity and of floating rate debt by interest rate repricing dates. For the purpose of this table, debt is defined as all classes of borrowings other than obligations under finance leases.

	2017			2016
	Total debt £m			Total £m
Floating and fixed rate debt less than one year		(2,802	)		(4,106	)
Between one and two years		(1,340	)		(2,216	)
Between two and three years		(1,076	)		(1,277	)
Between three and four years		(16	)		—
Between four and five years		(1,475	)		—
Between five and ten years		(3,664	)		(4,082	)
Greater than ten years		(6,650	)		(7,045	)
Total		(17,023	)		(18,726	)
Original issuance profile:
Fixed rate interest		(16,209	)		(17,342	)
Floating rate interest		(765	)		(1,381	)
Total interest bearing		(16,974	)		(18,723	)
Non-interest bearing		(49	)		(3	)
		(17,023	)		(18,726	)

(g) Sensitivity analysis

The tables below illustrate the estimated impact on the income statement and equity as a result of hypothetical market movements in foreign exchange and interest rates in relation to the Group’s financial instruments. The range of variables chosen for the sensitivity analysis reflects management’s view of changes which are reasonably possible over aone-year period.

Foreign exchange sensitivity

The Group operates internationally and is primarily exposed to foreign exchange risk in relation to Sterling against movements in US Dollar, Euro and Japanese Yen. Foreign exchange risk arises from the translation of financial assets and liabilities which are not in the functional currency of the entity that holds them. Based on the Group’s net financial assets and liabilities as at 31 December, a weakening and strengthening of Sterling against these currencies, with all other variables held constant, is illustrated in the tables below. The tables exclude financial instruments that expose the Group to foreign exchange risk where this risk is fully hedged with another financial instrument.

	2017			2016
Income statement impact of non-functional currency foreign exchange exposures	Increase/(decrease) in income £m			Increase/(decrease) in income £m
10 cent appreciation of the US Dollar		76			77
10 cent appreciation of the Euro		(5	)		18
10 yen appreciation of the Yen		9			1
	2017			2016
Income statement impact of non-functional currency foreign exchange exposures	Increase/(decrease) in income £m			Increase/(decrease) in income £m
10 cent depreciation of the US Dollar		(66	)		(66	)
10 cent depreciation of the Euro		4			(16	)
10 yen depreciation of the Yen		(8	)		(1	)

The equity impact, shown below, for foreign exchange sensitivity relates to derivative and non-derivative financial instruments hedging the Group’s net investments in its European (Euro) foreign operations and cash flow hedges of its foreign exchange exposure arising on Euro denominated coupon payments relating to notes issued under the Group’s European Medium Term Note programme and a number of highly probable forecast transactions denominated in US Dollar.

	2017			2016
Equity impact of non-functional currency foreign exchange exposures	Increase/(decrease) in equity £m			Increase/(decrease) in equity £m
10 cent appreciation of the US Dollar		1			11
10 cent appreciation of the Euro		(1,028	)		(795	)
	2017			2016
Equity impact of non-functional currency foreign exchange exposures	Increase/(decrease) in equity £m			Increase/(decrease) in equity £m
10 cent depreciation of the US Dollar		(1	)		(10	)
10 cent depreciation of the Euro		861			670

The tables below present the Group’s sensitivity to a weakening and strengthening of Sterling against the relevant currency based on the composition of net debt as shown in Note 31 adjusted for the effects of foreign exchange derivatives that are not part of net debt but affect future foreign currency cash flows.

	2017			2016
Impact of foreign exchange movements on net debt	(Increase)/decrease in net debt £m			(Increase)/decrease in net debt £m
10 cent appreciation of the US Dollar		(637	)		(746	)
10 cent appreciation of the Euro		197			190
10 yen appreciation of the Yen		(4	)		(11	)
	2017			2016
Impact of foreign exchange movements on net debt	(Increase)/decrease in net debt £m			(Increase)/decrease in net debt £m
10 cent depreciation of the US Dollar		549			634
10 cent depreciation of the Euro		(165	)		(160	)
10 yen depreciation of the Yen		4			10

Interest rate sensitivity

The Group is exposed to interest rate risk on its outstanding borrowings and investments where any changes in interest rates will affect future cash flows or the fair values of financial instruments.

The majority of debt is issued at fixed interest rates and changes in the floating rates of interest do not significantly affect the Group’s net interest charge, although the majority of cash and liquid investments earn floating rates of interest.

The table below hypothetically shows the Group’s sensitivity to changes in interest rates in relation to Sterling, US Dollar and Euro floating rate financial assets and liabilities. If the interest rates applicable to floating rate financial assets and liabilities were to have increased by 1% (100 basis points), and assuming other variables had remained constant, it is estimated that the Group’s finance income for 2017 would have increased by approximately £5 million (2016 – £3 million increase). A 1% (100 basis points) movement in interest rates is not deemed to have a material effect on equity.

	2017			2016
Income statement impact of interest rate movements	Increase/(decrease) in income £m			Increase/(decrease) in income £m
1% (100 basis points) increase in Sterling interest rates		24			3
1% (100 basis points) increase in US Dollar interest rates		(24	)		(3	)
1% (100 basis points) increase in Euro interest rates		5			3

(h) Contractual cash flows for non-derivative financial liabilities and derivative instruments

The following tables provides an analysis of the anticipated contractual cash flows including interest payable for the Group’s non-derivative financial liabilities on an undiscounted basis. The Group did not use interest rate swaps to manage its interest rate risk. For the purpose of this table, debt is defined as all classes of borrowings except for obligations under finance leases. Interest is calculated based on debt held at 31 December without taking account of future issuance. Floating rate interest is estimated using the prevailing interest rate at the balance sheet date. Cash flows in foreign currencies are translated using spot rates at 31 December. Contractual cash flows in respect of operating lease vacant space provisions are excluded from the table below as they are included in the Commitments under non-cancellable operating leases table in Note 41, ‘Commitments’.

							Obligations			Finance charge on			Trade payables and
				Interest on			under finance			obligations under			other liabilities not
	Debt			debt			leases			finance leases			in net debt			Total
At 31 December 2017	£m			£m			£m			£m			£m			£m
Due in less than one year		(2,802	)		(555	)		(23	)		(2	)		(21,521	)		(24,903	)
Between one and two years		(1,344	)		(497	)		(27	)		(2	)		(853	)		(2,723	)
Between two and three years		(1,078	)		(488	)		(8	)		(1	)		(813	)		(2,388	)
Between three and four years		(16	)		(488	)		(2	)		(1	)		(784	)		(1,291	)
Between four and five years		(1,483	)		(468	)		(1	)		(1	)		(752	)		(2,705	)
Between five and ten years		(3,694	)		(2,018	)		(5	)		(5	)		(3,609	)		(9,331	)
Greater than ten years		(6,720	)		(3,996	)		—			—			(1,471	)		(12,187	)
Gross contractual cash flows		(17,137	)		(8,510	)		(66	)		(12	)		(29,803	)		(55,528	)
										Finance charge on			Trade payables and
							Obligations			obligations			other
				Interest on			under finance			under finance			liabilities not
	Debt			debt			leases			leases			in net debt			Total
At 31 December 2016	£m			£m			£m			£m			£m			£m
Due in less than one year		(4,108	)		(705	)		(23	)		(2	)		(11,621	)		(16,459	)
Between one and two years		(2,218	)		(566	)		(22	)		(1	)		(8,784	)		(11,591	)
Between two and three years		(1,282	)		(503	)		(12	)		—			(961	)		(2,758	)
Between three and four years		—			(496	)		(7	)		—			(786	)		(1,289	)
Between four and five years		—			(496	)		—			—			(705	)		(1,201	)
Between five and ten years		(4,117	)		(2,122	)		—			—			(3,474	)		(9,713	)
Greater than ten years		(7,124	)		(4,522	)		—			—			(3,135	)		(14,781	)
Gross contractual cash flows		(18,849	)		(9,410	)		(64	)		(3	)		(29,466	)		(57,792	)

The increase in contractual cash flows for non-derivative financial liabilities due in less than one year of £8.4 billion and the decrease in cash flows due between one and two years of £8.9 billion principally reflect the move of the Consumer Healthcare put option into amounts due in less than one year. This option relates to the ability of Novartis to put its shares in the Consumer Healthcare Joint Venture to GSK at certain points commencing on 2 March 2018 with payment likely to be due several months after exercise. See Note 27 ‘Trade and other payables’ for further information on the Consumer Healthcare put option.

Anticipated contractual cash flows for the repayment of debt and debt interest have decreased by £2.6 billion over the year due to a reduction in the issuance of commercial paper and favourable exchange rate movements on US Dollar denominated debt.

The table below provides an analysis of the anticipated contractual cash flows for the Group’s derivative instruments excluding embedded derivatives and equity options, which are not material, using undiscounted cash flows. Cash flows in foreign currencies are translated using spot rates at 31 December. The gross cash flows of foreign exchange contracts are presented for the purpose of this table although, in practice, the Group uses standard settlement arrangements to reduce its liquidity requirements on these instruments.

The amounts receivable and payable in less than one year have decreased compared with 31 December 2016 as a result of reduced hedging of the US commercial paper programme.

	2017					2016
	Receivables		Payables			Receivables		Payables
	£m		£m			£m		£m
Due in less than one year		20,319		(20,326	)		21,266		(21,303	)
Between one and two years		—		—			20		(20	)
Gross contractual cash flows		20,319		(20,326	)		21,286		(21,323	)

XML

Employee share schemes

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Employee share schemes

43. Employee share schemes

GSK operates several employee share schemes, including the Share Value Plan, whereby awards are granted to employees to acquire shares or ADS in GlaxoSmithKline plc at no cost after a three year vesting period and the Performance Share Plan, whereby awards are granted to employees to acquire shares or ADS in GlaxoSmithKline plc at no cost, subject to the achievement by the Group of specified performance targets. The granting of these restricted share awards has replaced the granting of options to employees as the cost of the schemes more readily equates to the potential gain to be made by the employee. The Group also operates savings related share option schemes, whereby options are granted to employees to acquire shares in GlaxoSmithKline plc at a discounted price.

Grants of restricted share awards are normally exercisable at the end of the three year vesting or performance period. Awards are normally granted to employees to acquire shares or ADS in GlaxoSmithKline plc but in some circumstances may be settled in cash. Grants under savings-related share option schemes are normally exercisable after three years’ saving. In accordance with UK practice, the majority of options under the savings-related share option schemes are granted at a price 20% below the market price ruling at the date of grant. Options under historical share option schemes were granted at the market price ruling at the date of grant.

The total charge for share-based incentive plans in 2017 was £347 million (2016 – £338 million; 2015 – £349 million). Of this amount, £276 million (2016 – £271 million; 2015 – £307 million) arose from the Share Value Plan. See Note 9, ‘Employee Costs’ for further details.

GlaxoSmithKline share award schemes

Share Value Plan

Under the Share Value Plan, share awards are granted to certain employees at no cost. The awards vest after two and a half to three years and there are no performance criteria attached. The fair value of these awards is determined based on the closing share price on the day of grant, after deducting the expected future dividend yield of 4.8% (2016 – 4.5%; 2015 – 5.7%) over the duration of the award.

	Shares			Weighted		ADS			Weighted
Number of shares and ADS issuable	Number (000)			fair value		Number (000)			fair value
At 1 January 2015		32,912					21,227
Awards granted		13,019		£	11.57		7,198		$	35.66
Awards exercised		(11,476	)				(8,878	)
Awards cancelled		(1,878	)				(2,027	)
At 31 December 2015		32,577					17,520
Awards granted		12,983		£	14.97		6,589		$	39.18
Awards exercised		(11,198	)				(6,214	)
Awards cancelled		(1,507	)				(812	)
At 31 December 2016		32,855					17,083
Awards granted		13,018		£	13.68		6,610		$	35.63
Awards exercised		(10,596	)				(5,674	)
Awards cancelled		(1,352	)				(627	)
At 31 December 2017		33,925					17,392

Performance Share Plan

Under the Performance Share Plan, share awards are granted to Directors and senior executives at no cost. The percentage of each award that vests is based upon the performance of the Group over a defined measurement period with dividends reinvested during the same period. For awards granted from 2015, the performance conditions are based on three equally weighted measures over a three year performance period. These are adjusted free cash flow, TSR and R&D new product performance.

The fair value of the awards is determined based on the closing share price on the day of grant. For TSR performance elements, this is adjusted by the likelihood of that condition being met, as assessed at the time of grant.

During 2017, awards were made of 3.9 million shares at a weighted fair value of £11.09 and 1.0 million ADS at a weighted fair value of $32.85. At 31 December 2017, there were outstanding awards over 12.9 million shares and 3.2 million ADS.

Share options and savings-related options

For the purposes of valuing savings-related options to arrive at the share based payment charge, a Black-Scholes option pricing model has been used. The assumptions used in the model are as follows:

	2017 Grant			2016 Grant			2015 Grant
Risk-free interest rate		0.54	%		0.32	%		0.88	%
Dividend yield		5.9	%		4.9	%		6.5	%
Volatility		23	%		23	%		21	%
Expected life		3 years			3 years			3 years
Savings-related options grant price (including 20% discount)	£	10.86		£	12.95		£	10.14

	Share option					Share option					Savings-related
Options outstanding	schemes – shares					schemes –  ADS					share option schemes
				Weighted					Weighted					Weighted
	Number			exercise		Number			exercise		Number			exercise
	000			price		000			price		000			price
At 31 December 2017		3,600		£	11.86		3,277		$	39.62		6,852		£	10.77
Range of exercise prices on options outstanding at year end	£	11.47	–	£	12.21	$	33.42	–	$	48.66	£	10.13	–	£	12.95
Weighted average market price on exercise during year				£	16.07				$	41.50				£	14.28
Weighted average remaining contractual life					1.4 years					1.0 years					2.1 years

Options over 2.0 million shares were granted during the year under the savings-related share option scheme at a weighted average fair value of £2.08. At 31 December 2017, 6.7 million of the savings-related share options were not exercisable. All of the other share options and ADS options are currently exercisable and all will expire if not exercised on or before 22 July 2020.

There has been no change in the effective exercise price of any outstanding options during the year.

Employee Share Ownership Plan Trusts

The Group sponsors Employee Share Ownership Plan (ESOP) Trusts to acquire and hold shares in GlaxoSmithKline plc to satisfy awards made under employee incentive plans and options granted under employee share option schemes. The trustees of the ESOP Trusts purchase shares with finance provided by the Group by way of loans or contributions. In 2017, Treasury shares with a carrying value of £610 million were purchased by the US ESOP Trust to satisfy future awards. The costs of running the ESOP Trusts are charged to the income statement. Shares held by the ESOP Trusts are deducted from other reserves and amortised down to the value of proceeds, if any, receivable from employees on exercise by a transfer to retained earnings. The trustees have waived their rights to dividends on the shares held by the ESOP Trusts.

Shares held for share award schemes	2017		2016
Number of shares (000)		66,558		42,571
	£m		£m
Nominal value		17		11
Carrying value		399		285
Market value		880		665
Shares held for share option schemes	2017		2016
Number of shares (000)		139		139
	£m		£m
Nominal value		—		—
Carrying value		1		1
Market value		2		2

XML

Principal Group companies

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Principal Group companies

44. Principal Group companies

The following represent the principal subsidiaries and their countries of incorporation of the Group at 31 December 2017. The equity share capital of these entities is wholly owned by the Group except where its percentage interest is shown otherwise. All companies are incorporated in their principal country of operation except where stated.

England	US
Glaxo Group Limited	Block Drug Company, Inc. (63.5%)
Glaxo Operations UK Limited	Corixa Corporation
GlaxoSmithKline Capital plc	GlaxoSmithKline Capital Inc.
GlaxoSmithKline Consumer Healthcare Holdings Limited (63.5%)	GlaxoSmithKline Consumer Healthcare, L.P. (55.9%)
GlaxoSmithKline Consumer Healthcare (UK) Trading Limited (63.5%)	GlaxoSmithKline Holdings (Americas) Inc.
GlaxoSmithKline Export Limited	GlaxoSmithKline LLC
GlaxoSmithKline Finance plc	Human Genome Sciences, Inc.
GlaxoSmithKline Holdings Limited *	GSK Consumer Health, Inc. (formerly Novartis Consumer Health, Inc.) (63.5%)
GlaxoSmithKline Research & Development Limited	S.R. One, Limited
GlaxoSmithKline Services Unlimited *	Stiefel Laboratories, Inc.
GlaxoSmithKline UK Limited	ViiV Healthcare Company (78.3%)
Setfirst Limited
SmithKline Beecham Limited
ViiV Healthcare Limited (78.3%)
ViiV Healthcare UK Limited (78.3%)
Europe	Others
GlaxoSmithKline Biologicals SA (Belgium)	GlaxoSmithKline Argentina S.A. (Argentina)
GlaxoSmithKline Pharmaceuticals SA (Belgium)	GlaxoSmithKline Australia Pty Ltd (Australia)
GlaxoSmithKline Biologicals S.A.S. (France)	GlaxoSmithKline Consumer Healthcare Australia Pty Ltd (Australia) (63.5%)
GlaxoSmithKline Sante Grand Public SAS (France) (63.5%)	GlaxoSmithKline Brasil Limitada (Brazil)
Laboratoire GlaxoSmithKline (France)	GlaxoSmithKline Consumer Healthcare Inc. (Canada) (63.5%)
ViiV Healthcare SAS (France) (78.3%)	GlaxoSmithKline Inc. (Canada)
GlaxoSmithKline Consumer Healthcare GmbH & Co. KG	ID Biomedical Corporation of Quebec (Canada)
(Germany) (63.5%)	GlaxoSmithKline Limited (China (Hong Kong))
GlaxoSmithKline GmbH & Co. KG (Germany)	Sino-American Tianjin Smith Kline & French Laboratories Ltd (China) (34.9%)
GSK Vaccines GmbH (Germany)	GlaxoSmithKline Consumer Healthcare Limited (India) (72.5%)
GlaxoSmithKline Consumer Healthcare S.p.A. (Italy) (63.5%)	GlaxoSmithKline Pharmaceuticals Limited (India) (75%)
GlaxoSmithKline S.p.A. (Italy)	GlaxoSmithKline Consumer Healthcare Japan K.K. (Japan) (63.5%)
GSK Vaccines S.r.l. (Italy)	GlaxoSmithKline K.K. (Japan)
GlaxoSmithKline B.V. (Netherlands)	ViiV Healthcare Kabushiki Kaisha (Japan) (78.3%)
GlaxoSmithKline Consumer Healthcare Sp.z.o.o. (Poland) (63.5%)	GlaxoSmithKline Pakistan Limited (Pakistan) (82.6%)
GlaxoSmithKline Pharmaceuticals S.A. (Poland)	Glaxo Wellcome Manufacturing Pte Ltd. (Singapore)
GSK Services Sp z o.o. (Poland)	GlaxoSmithKline Korea Limited (Republic of Korea)
GlaxoSmithKline Trading Services Limited (Republic of Ireland) (i)	GlaxoSmithKline llaclari Sanayi ve Ticaret A.S. (Turkey)
GlaxoSmithKline Healthcare AO (Russia) (63.5%)
GlaxoSmithKline S.A. (Spain)
Laboratorios ViiV Healthcare, S.L. (Spain) (78.3%)
Novartis Consumer Health S.A. (Switzerland) (63.5%)

(i) Exempt from the provisions of section 347 and 348 of the Companies Act 2014 (Ireland), in accordance with the exemptions noted in Section 357 of that Act. Further subsidiaries, as disclosed on pages 276 to 286, are exempt from these provisions as they are also consolidated in the group financial statements.

* Directly held wholly owned subsidiary of GlaxoSmithKline plc.

The subsidiaries and associates listed above principally affect the figures in the Group’s financial statements. Each of GlaxoSmithKline Capital Inc., GlaxoSmithKline Capital plc and GlaxoSmithKline LLC, is a wholly-owned finance subsidiary of the company, and the company has fully and unconditionally guaranteed the securities issued by each of GlaxoSmithKline Capital Inc., GlaxoSmithKline Capital plc and GlaxoSmithKline LLC.

See pages 276 to 286 for a complete list of subsidiary undertakings, associates and joint ventures, which form part of these financial statements.

XML

Legal proceedings

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Legal proceedings

45. Legal proceedings

The Group is involved in significant legal and administrative proceedings, principally product liability, intellectual property, tax, anti-trust and governmental investigations, as well as related private litigation. The most significant of these matters, other than tax matters, are described below. The Group makes provision for these proceedings on a regular basis as summarised in Note 2, ‘Accounting principles and policies’ and Note 29, ‘Other provisions’.

The Group may become involved in significant legal proceedings in respect of which it is not possible to make a reliable estimate of the expected financial effect, if any, that could result from ultimate resolution of the proceedings. In these cases, appropriate disclosures about such cases would be included in this note, but no provision would be made for the cases.

With respect to each of the legal proceedings described below, other than those for which a provision has been made, the Group is unable to make a reliable estimate of the expected financial effect at this stage. The Group does not believe that information about the amount sought by the plaintiffs, if that is known, would be meaningful with respect to those legal proceedings. This is due to a number of factors, including, but not limited to, the stage of proceedings, the entitlement of parties to appeal a decision and clarity as to theories of liability, damages and governing law.

Legal expenses incurred and provisions related to legal claims are charged to selling, general and administration costs. Provisions are made, after taking appropriate legal and other specialist advice, where an outflow of resources is considered probable and a reliable estimate can be made of the likely outcome of the dispute. For certain product liability claims, the Group will make a provision where there is sufficient history of claims made and settlements to enable management to make a reliable estimate of the provision required to cover unasserted claims. At 31 December 2017, the Group’s aggregate provision for legal and other disputes (not including tax matters described in Note 14, ‘Taxation’) was £186 million. The ultimate liability for legal claims may vary from the amounts provided and is dependent upon the outcome of litigation proceedings, investigations and possible settlement negotiations.

The Group’s position could change over time, and, therefore, there can be no assurance that any losses that result from the outcome of any legal proceedings will not exceed by a material amount the amount of the provisions reported in the Group’s financial statements. If this were to happen, it could have a material adverse impact on the results of operations of the Group in the reporting period in which the judgements are incurred or the settlements entered into.

Intellectual property

Intellectual property claims include challenges to the validity and enforceability of the Group’s patents on various products or processes as well as assertions of non-infringement of those patents. A loss in any of these cases could result in loss of patent protection for the product at issue. The consequences of any such loss could be a significant decrease in sales of that product and could materially affect future results of operations for the Group.

Flovent HFA

On 15 February 2017, the Group received a Paragraph IV certification from Teva for Flovent HFA. This was the first Paragraph IV certification the Group had received from a generic pharmaceutical company seeking to make an AB rated version of Flovent HFA. Three patents are at issue. Teva alleged that its generic version of Flovent did not infringe two patents directed to actuation indicators (metered dose) listed in the Orange Book. Teva also alleged that U.S. Patent No. 6,743, 413 (‘413 patent’) which claims a method of treatment with a formulation containing an active medication and a propellant known as 134a, substantially free of surfactant, and its use in the hydrofluoroalkane (HFA) metered dose inhalers for Flovent is not valid. After reviewing the Teva complaint, the Group did not sue Teva under the ‘413 patent and asked the FDA to remove the ‘413 patent from the Orange Book. Teva produced evidence showing that it did not infringe the dose counter patents. On 20 June 2017, the Group withdrew the case against Teva.

Bexsero/Men B vaccines

Following its acquisition of the Novartis Vaccines business, the Group took over patent litigation originally filed by Novartis against Pfizer, Inc. (Pfizer) in the UK, Italy and the United States related to meningococcal B (Men B) vaccines. In various cases, Novartis had alleged that European patents owned by Pfizer were not infringed by the Group’s vaccine, Bexsero and were invalid. Novartis had also filed suit against Pfizer for patent infringement, alleging that Pfizer’s sale of its vaccine, Trumenba, infringes Novartis’ patents related to Men B vaccines. Pfizer had filed suit against the Group in the UK seeking to invalidate six UK patents owned by the Group that have relevance to Trumenba and in Canada for infringement of a patent covering Trumenba. On 24 April 2017, the Group and Pfizer entered into a confidential global settlement resolving all matters that permits each company to manufacture and sell their respective Men B vaccines.

Dolutegravir/Tivicay/Triumeq

In September and October, 2017, ViiV Healthcare received patent challenge letters under the Hatch-Waxman Act from Lupin, Mylan, Cipla and Dr. Reddy’s Labs for Triumeq, and from Cipla, Dr. Reddy’s, Apotex and Sandoz for Tivicay and Triumeq. ViiV Healthcare lists two patents for dolutegravir, the active ingredient in Tivicay and one of the active ingredients in Triumeq, in the FDA Orange Book. One patent, covering the molecule dolutegravir, expires on 5 October 2027. A second patent, claiming a certain crystal form of dolutegravir, expires on 8 December 2029. All the letters challenged only the patent for the crystal form. Some generic companies alleged that the crystal form patent is not valid. Others challenged validity and asserted that their proposed product would not infringe the crystal form patent. On 7 February 2017, ViiV Healthcare filed patent infringement suits against all the generic companies in the US District Court for the District of Delaware. Additionally, ViiV Healthcare also filed suit against certain of the generic companies in the US District Court for the District of New Jersey, and the US District Court for the District of West Virginia. No trial date has yet been set.

On 7 February 2018, ViiV Healthcare filed patent infringement litigation against Gilead Sciences Inc. (Gilead) over bictegravir in the US District Court for the District of Delaware (US Patent No. 8,129,385) and the Canadian Federal Court (Canadian Patent No. 2,606,282). ViiV Healthcare alleges that Gilead’s triple combination HIV drug containing the HIV integrase inhibitor bictegravir infringes ViiV Healthcare’s patent covering dolutegravir and other compounds that include dolutegravir’s unique chemical scaffold. In both the US and Canada, ViiV Healthcare seeks financial redress rather than injunctive relief. No trial date has yet been set.

Kivexa

Between Q1 2017 and Q1 2018, ViiV Healthcare reached confidential agreements with each of Vale Pharmaceuticals, Lupin, Sandoz, STADA and Zentiva to settle various challenges to the validity of the Supplementary Protection Certificate (‘SPC’) for the patent covering the combination of lamivudine and abacavir for Kivexa and certain counterclaims brought by ViiV Healthcare for infringement of that SPC. These settlements brought an end to litigation and arbitration proceedings between ViiV Healthcare and Lupin in Germany and Portugal, between ViiV Healthcare and STADA in Germany and Italy, between ViiV Healthcare and Sandoz in Austria, Germany, Portugal, Spain and Sweden, between ViiV Healthcare and Vale Pharmaceuticals in Portugal, and between ViiV Healthcare and Zentiva in Portugal.

DOC Generici filed an action in September 2016 in the Court of Rome seeking a declaration that the Italian SPC covering Kivexa was invalid because it is based upon the invalid lamivudine and abacavir combination patent. ViiV Healthcare has counterclaimed for infringement of the Italian SPC. The trial in this action is to be heard in Q3 2018.

In June 2017, Biogaran commenced proceedings in France seeking revocation of the French SPC covering Kivexa. No trial date has been set for this action.

In Portugal, ViiV Healthcare initiated arbitration proceedings against Farmoz under the SPC covering Kivexa. Farmoz had filed for marketing approval for a generic version of Kivexa. No arbitration date has yet been scheduled in this action.

In February 2017, Kyowa Pharmaceuticals filed a nullity action relating to Kivexa in Japan. Oral hearing of the trial was held at the Japan Patent Office on 30 January 2018. The decision of the Japan Patent Office is expected in 2018.

Lexiva

The US patent covering Lexiva expired on 24 December 2017 and the product has paediatric exclusivity until 24 June 2018. Pursuant to a settlement of a litigation and confidential licence agreement, Mylan is presently selling a generic version of Lexiva in the US.

Product liability

Pre-clinical and clinical trials are conducted during the development of potential products to determine the safety and efficacy of products for use by humans following approval by regulatory bodies.

Notwithstanding these efforts, when drugs and vaccines are introduced into the marketplace, unanticipated safety issues may become, or be claimed by some to be, evident. The Group is currently a defendant in a number of product liability lawsuits related to the Group’s Pharmaceutical, Vaccine and Consumer Healthcare products. The Group has been able to make a reliable estimate of the expected financial effect of the matters discussed in this category and has included a provision, as appropriate, for the matters below in the provision for legal and other disputes. Matters for which the Group has made a provision are also noted in Note 29, ‘Other provisions.

Avandia

The Group has been named in product liability lawsuits on behalf of individuals asserting personal injury claims arising out of the use of Avandia. Economic loss actions have also been filed seeking restitution and penalties under consumer protection and other laws. The federal cases filed against the Group are part of a multi-district litigation proceeding pending in the US District Court for the Eastern District of Pennsylvania (the ‘MDL Court’). Cases have also been filed in a number of state courts. In addition, the County of Santa Clara, California, has brought an action on behalf of California residents which is pending in the MDL Court, alleging violations of California’s False Advertising Act and seeking restitution, damages, and civil penalties.

As of February 2018, there are five remaining personal injury cases on appeal from summary judgement decisions in favour of the Group (one in federal court in Pennsylvania and four in California state court).

There were four purported class actions in the US seeking economic damages on behalf of third party payers asserting claims under the Racketeer Influenced and Corrupt Organizations Act (RICO) and consumer protection laws. Two plaintiffs voluntarily dismissed their actions. On 7 December 2017, the MDL Court granted the Group’s motion for summary judgement on the two remaining plaintiffs’ claims. Plaintiffs have filed an appeal of the decision in the US Court of Appeals for the Third Circuit, and a briefing schedule has been set.

In the Santa Clara County action, the Group filed a motion for summary judgement on the basis of pre-emption and also is seeking partial summary judgement on the County’s restitution claim. On 7 December 2017, the MDL Court granted the Group’s motion. The County’s claims for civil penalties remain pending before the MDL Court.

There are 13 purported class actions in Canada, two of which are active. In the two active cases, class certification hearings were held. In the Ontario action, the proceedings were adjourned. On 7 December 2017, the Nova Scotia court issued an Order certifying a nationwide class of all users of Avandia. The Group has filed an appeal of that class certification decision.

Seroxat/Paxil and Paxil CR

The Group has received numerous lawsuits and claims alleging that use of Paxil (paroxetine) has caused a variety of injuries. Most of these lawsuits contain one or more of the following allegations: (i) that use of Paxil during pregnancy caused congenital malformations, persistent pulmonary hypertension or autism; (ii) that Paxil treatment caused patients to commit suicidal or violent acts; and (iii) that the Group failed to warn that patients could experience certain symptoms on discontinuing Paxil treatment.

– Pregnancy

The Group has reached agreements to settle the majority of the US claims relating to the use of Paxil during pregnancy as of February 2018, but a number of claims related to use during pregnancy are still pending in various courts in the US. Of these remaining lawsuits, there are three cases still pending in state court in California and one in federal court in California. There is one case in state court in Kentucky, one in state court in Oklahoma, and one lawsuit joining the claims of eight plaintiffs in state court in Illinois. Other matters have been dismissed without payment.

The Singh action in Alberta, Canada, a proposed national class action, seeks to certify a class relating to birth defects generally. The Group is awaiting a hearing on the motion in Singh to certify the case as a class action. Another Canadian class action, Jensen, alleging claims of Paxil (and other SSRI) use and autism was filed in Saskatchewan in January 2017. On 27 March 2017, court approval was received for the settlement of Bartram, a third class action suit in British Columbia.

– Acts of violence

As of February 2018, there were six pending claims or cases concerning allegations that patients who took paroxetine or Paxil committed or attempted to commit suicide or acts of violence: five claims or cases are in the US and one case is in Canada. One of the US cases, Dolin, involving the suicide of a man who allegedly took generic paroxetine manufactured by Mylan, resulted in a $3 million verdict for the plaintiff. The Group has appealed the verdict to the US Court of Appeals for the Seventh Circuit.

– Discontinuation

In the UK, a long-pending group action alleges that Seroxat caused severe discontinuation symptoms. In 2010, the Legal Services Commission (“LSC”) withdrew public funding from hundreds of claimants, causing termination of most claims. In 2015, the Legal Aid Agency (formerly the LSC) discharged the public funding certificate following a 2013 recommendation of its Special Cases Review Panel that these cases have poor prospects of success. However, more recently, Fortitude Law was engaged with the purpose of resurrecting the Seroxat group action, and obtained third-party funding for the experts and the 103 remaining claimants. The Group asked the court to require the third-party funder to provide security for the litigation costs in the event plaintiffs lose. On 8 December 2017, the High Court ruled in favour of the Group on its application for an order that the claimants’ litigation funder give security for costs for a sum in excess of the total funding it had committed to the case. The trial of the action is scheduled to commence in May 2019.

Zofran

Plaintiffs allege that their children suffered birth defects as a result of the mothers’ ingestion of Zofran and/or generic ondansetron for pregnancy-related nausea and vomiting. Plaintiffs assert that the Group sold Zofran knowing it was unsafe for pregnant women, failed to warn of the risks, and illegally marketed Zofran “off-label” for use by pregnant women. As of February 2018, the Group is a defendant in 420 personal injury lawsuits in the US. 406 of the cases are part of a multi-district litigation proceeding (MDL) in the District of Massachusetts.

The MDL cases are in discovery. The MDL continues with monthly status conferences where issues such as the sufficiency of the pleadings and the scope of discovery will be addressed. The Group continues to seek the dismissal of individual cases as appropriate.

The Brown case pending in Oregon is in discovery and is scheduled for trial in October 2018. The remaining nine state court cases in the US, eight of which are in California, are still in their early days. The Group is also a defendant in four proposed class actions in Canada. There has been no significant activity in 2017 in the Canadian class actions.

Sales and marketing and regulation

The Group’s marketing and promotion of its Pharmaceutical and Vaccine products are the subject of certain governmental investigations and private lawsuits brought by litigants under various theories of law. The Group has been able to make a reliable estimate of the expected financial effect of the matters discussed in this category, and has included a provision for such matters in the provision for legal and other disputes, except as noted below.

Matters for which the Group has made a provision are also noted in Note 29, ‘Other provisions’.

SEC/DOJ and SFO Anti-corruption enquiries

On 27 May 2014, the UK Serious Fraud Office (SFO) began a formal criminal investigation into the Group’s commercial operations in a number of countries, including China. The Group is co-operating with and responding to these requests. The SFO inquiry followed investigations initiated by China’s Ministry of Public Security in June 2013 (the “China Investigations”) which resulted in a ruling in 2014 that, according to Chinese law, GSK China Investment Co. Ltd. (“GSKCI”) had offered money or property to non-government personnel in order to obtain improper commercial gains and GSKCI being found guilty of bribing non-government personnel.

On 30 September 2016, the Group reached a global resolution with the US Securities and Exchange Commission (SEC) regarding the SEC’s investigation under the US Foreign Corrupt Practices Act (FCPA) into the Group’s commercial practices in countries outside of the US, including China. As part of the resolution, the Group agreed to pay a civil penalty of $20 million to the US Government. The US Department of Justice (DOJ) confirmed that it had concluded its investigation into the Group’s commercial practices and would take no action against the Group. As part of the resolution with the SEC, the Group agreed to certain undertakings, including a period of self-monitoring and reporting. The Group’s obligations under that resolution continue through 30 September 2018.

In the course of its current inquiry, the SFO has requested additional information from the Group regarding third party advisers engaged by the company in the course of the China Investigations. The SEC and DOJ are also investigating these matters following the Group’s reporting of the SFO’s inquiries. The Group is co-operating and responding to these requests.

The Group is unable to make a reliable estimate of the expected financial effect of these investigations, and no provision has been made for them.

US Vaccines subpoena

On 25 February 2016, the Group received a subpoena from the US Attorney’s Office for the Southern District of New York requesting documents relating to the Group’s Vaccines business. The Group is responding to the subpoena. The Group is unable to make a reliable estimate of the expected financial effect of this matter, and no provision has been made for it.

US subpoena relating to Imitrex and Amerge

On 7 March 2016, the Group received a subpoena from the US Attorney’s Office for the Southern District of New York requesting documents relating to the Group’s US contracts for Imitrex and Amerge. The Group has completed its response to the subpoena. The Group is unable to make a reliable estimate of the expected financial effect of this matter, and no provision has been made for it.

Average wholesale price

The Attorney General in Illinois filed suit against the Group and a number of other pharmaceutical companies claiming damages and restitution due to average wholesale price (AWP) and/or wholesale acquisition cost (WAC) price reporting for pharmaceutical products covered by the state’s Medicaid programmes. The case alleges that the Group reported or caused to be reported false AWP and WAC prices, which, in turn, allegedly caused the state Medicaid agency to reimburse providers more money for covered medicines than the agency intended. The state has sought recovery on behalf of itself as payer and on behalf of in-state patients as consumers. The case is ongoing, and no trial date has yet been set as to the Group.

Cidra third-party payer litigation

On 25 July 2013, a number of major US healthcare insurers filed suit against the Group in the Philadelphia, Pennsylvania County Court of Common Pleas seeking compensation for reimbursements they made for medicines manufactured at the Group’s former Cidra plant in Puerto Rico. These insurers claim that the Group knowingly and illegally marketed and sold adulterated drugs manufactured under conditions non-compliant with cGMP (current good manufacturing practices) and that they, as third-party insurers, were unlawfully induced to pay for them. The suit alleges both US federal and various state law causes of action. The Court denied the Group’s motion to dismiss and discovery is scheduled to be completed in 2018, with the case to be scheduled for trial sometime in late 2018.

Anti-trust/competition

Certain governmental actions and private lawsuits have been brought against the Group alleging violation of competition or anti-trust laws. The Group has been able to make a reliable estimate of the expected financial effect of the matters discussed in this category and has included a provision for such matters in the provision for legal and other disputes, except as noted below. Matters for which the Group has made a provision are also noted in Note 29, ‘Other provisions’.

UK Competition and Markets Authority investigation On 12 February 2016, the UK Competition and Markets Authority (CMA) issued a decision fining the Group and two other pharmaceutical companies for infringement of the Competition Act. The CMA imposed a fine of £37.6 million on the Group, as well as fines totaling £7.4 million against the other companies. This relates to agreements to settle patent disputes between the Group and potential suppliers of generic paroxetine formulations, entered between 2001 and 2003. The Group terminated the agreements at issue in 2004. The Group believes it has strong grounds for its appeal of the CMA’s finding to the Competition Appeal Tribunal (CAT) in order to overturn the fine or substantially reduce it. The appeal concluded in April 2017. The CAT delivered its initial judgement on the appeal on 8 March 2018 referring all the principle points at issue to the Court of Justice of the EU for a preliminary ruling. The matter will then return to the CAT for final judgement. No provision has been made for this matter.

Lamictal

Purported classes of direct and indirect purchasers filed suit in the US District Court for the District of New Jersey alleging that the Group and Teva Pharmaceuticals unlawfully conspired to delay generic competition for Lamictal, resulting in overcharges to the purchasers, by entering into an allegedly anti-competitive reverse payment settlement to resolve patent infringement litigation. A separate count accuses the Group of monopolising the market.

On 26 June 2015, the Court of Appeals reversed the trial court’s decision to dismiss the case and remanded the action back to the trial court. On 18 May 2016, the trial court denied the indirect purchaser class plaintiffs’ motion for reconsideration. As a result, the indirect purchaser class representatives have agreed to a settlement to exit the case and resolve their remaining claims. Terms of the settlement are confidential. The case will continue to move forward with document production and witness depositions with regard to the claims of the direct purchasers.

Wellbutrin XL

Plaintiffs claimed anti-trust injury related to allegedly sham patent litigation filed by Biovail against generic companies pursuing ANDAs for generic Wellbutrin XL. Plaintiffs alleged that a conspiracy to delay generic approval existed between Biovail and the Group, but the US District Court granted summary judgement in favour of the Group on those claims. The sole remaining claims in the matter relate to plaintiffs’ allegations that the Group entered into an anti-competitive reverse payment settlement to resolve the patent infringement litigation. The District Court granted summary judgement in favour of the Group on all claims. On 9 August 2017, the US Court of Appeals for the Third Circuit Court affirmed the trial court’s dismissal of plaintiffs’ case on summary judgement. On 31 August 2017, plaintiffs filed a motion for a rehearing en banc before the Third Circuit which was denied on 20 September 2017. Plaintiffs did not file a petition for certiorari asking the United States Supreme Court to review the decision, so the dismissal of the action is now final.

Commercial and corporate

The Group is a defendant in certain cases which allege violation of US federal securities and ERISA laws. The Group has been able to make a reliable estimate of the expected financial effect of the matters discussed in this category and has included a provision for such matters in the provision for legal and other disputes. Matters for which the Group has made a provision are also noted in Note 29, ‘Other provisions’.

Securities/ERISA class actions – Stiefel

On 12 December 2011, the US Securities and Exchange Commission (SEC) filed a formal complaint against Stiefel Laboratories, Inc. and Charles Stiefel in the US District Court for the District of Florida alleging that Stiefel and its principals violated federal securities laws by inducing Stiefel employees to sell their shares in the employee stock plan back to the company at a greatly undervalued price and without disclosing to employees that the company was about to be sold to the Group. The case was stayed while several private actions brought by former Stiefel employees proceeded through the courts, but was returned to active status in early summer 2015. It is unclear when the case ultimately will be scheduled for trial.

In addition to the SEC case, one private matter (the “Martinolich” case) remains. It is also pending in federal district court in Florida, but has been stayed pending the trial of the SEC matter. The allegations in the Martinolich case largely track those in the SEC matter: plaintiff, a former Stiefel employee, alleges that Stiefel and its officers and directors violated the US Employee Retirement Income Security Act (ERISA) and federal and state securities laws by inducing Stiefel employees to sell their shares in the employee stock plan back to Stiefel at a greatly undervalued price and without disclosing to employees that Stiefel was about to be sold to the Group.

Environmental matters

The Group has been notified of its potential responsibility relating to past operations and its past waste disposal practices at certain sites, primarily in the US. Some of these matters are the subject of litigation, including proceedings initiated by the US federal or state governments for waste disposal, site remediation costs and tort actions brought by private parties.

The Group has been advised that it may be a responsible party at approximately 19 sites, of which 10 appear on the National Priority List created by the Comprehensive Environmental Response Compensation and Liability Act (Superfund). These proceedings seek to require the operators of hazardous waste facilities, transporters of waste to the sites and generators of hazardous waste disposed of at the sites to clean up the sites or to reimburse the US Government for cleanup costs. In most instances, the Group is involved as an alleged generator of hazardous waste.

Although Superfund provides that the defendants are jointly and severally liable for cleanup costs, these proceedings are frequently resolved on the basis of the nature and quantity of waste disposed of by the generator at the site. The Group’s proportionate liability for cleanup costs has been substantially determined for 18 of the sites referred to above.

The Group’s potential liability varies greatly from site to site. The the cost of investigation, study and remediation at such sites could, over time, be significant. The Group has made a provision for these matters, as noted in Note 29, ‘Other provisions’.

XML

Presentation of the financial statements (Policies)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Implementation of new accounting standards and interpretations

Implementation of new accounting standards and interpretations

An agenda decision by the IFRS Interpretations Committee in September 2017 clarified that charges for interest on tax should be reported within finance expense and certain penalties on tax settlements should be reported within administrative expenses. Previously GSK had reported these charges within the overall tax charge in the income statement or other comprehensive income, as appropriate.

GSK has adopted the revised basis of reporting in 2017 and, as a result of a number of settlements during the year, has recorded credits for interest on tax for 2017 of £24 million in finance expense. There were no material charges for penalties on settlements during 2017 that required adjustment.

Accrued interest payable on tax at 31 December 2017 was £52 million, and this is included within trade and other payables on the Group balance sheet. The impact on prior years was not material and so prior year amounts have not been restated.

Consolidation

Consolidation

The consolidated financial statements include:

• the assets and liabilities, and the results and cash flows, of the company and its subsidiaries, including ESOP Trusts

• the Group’s share of the results and net assets of associates and joint ventures

• the Group’s share of assets, liabilities, revenue and expenses of joint operations.

The financial statements of entities consolidated are made up to 31 December each year.

Entities over which the Group has the power to direct the relevant activities so as to affect the returns to the Group, generally through control over the financial and operating policies, are accounted for as subsidiaries.

Where the Group has the ability to exercise joint control over, and rights to the net assets of, entities, the entities are accounted for as joint ventures. Where the Group has the ability to exercise joint control over an arrangement, but has rights to specified assets and obligations for specified liabilities of the arrangement, the arrangement is accounted for as a joint operation. Where the Group has the ability to exercise significant influence over entities, they are accounted for as associates. The results and assets and liabilities of associates and joint ventures are incorporated into the consolidated financial statements using the equity method of accounting. The Group’s rights to assets, liabilities, revenue and expenses of joint operations are included in the consolidated financial statements in accordance with those rights and obligations.

Interests acquired in entities are consolidated from the date the Group acquires control and interests sold are de-consolidated from the date control ceases.

Transactions and balances between subsidiaries are eliminated and no profit before tax is taken on sales between subsidiaries until the products are sold to customers outside the Group. The relevant proportion of profits on transactions with joint ventures, joint operations and associates is also deferred until the products are sold to third parties. Transactions with non-controlling interests are recorded directly in equity. Deferred tax relief on unrealised intra-Group profit is accounted for only to the extent that it is considered recoverable.

Business combinations

Business combinations

Business combinations are accounted for using the acquisition accounting method. Identifiable assets, liabilities and contingent liabilities acquired are measured at fair value at acquisition date. The consideration transferred is measured at fair value and includes the fair value of any contingent consideration. Where the consideration transferred, together with the non-controlling interest, exceeds the fair value of the net assets, liabilities and contingent liabilities acquired, the excess is recorded as goodwill. The costs of acquisition are charged to the income statement in the period in which they are incurred.

Goodwill is capitalised as a separate item in the case of subsidiaries and as part of the cost of investment in the case of joint ventures and associates. Goodwill is denominated in the currency of the operation acquired.

Where the cost of acquisition is below the fair value of the net assets acquired, the difference is recognised directly in the income statement.

Where not all of the equity of a subsidiary is acquired the non-controlling interest is recognised either at fair value or at the non-controlling interest’s share of the net assets of the subsidiary, on a case-by-case basis. Changes in the Group’s ownership percentage of subsidiaries are accounted for within equity.

Foreign currency translation

Foreign currency translation

Foreign currency transactions are booked in the functional currency of the Group company at the exchange rate ruling on the date of transaction. Foreign currency monetary assets and liabilities are retranslated into the functional currency at rates of exchange ruling at the balance sheet date. Exchange differences are included in the income statement.

On consolidation, assets and liabilities, including related goodwill, of overseas subsidiaries, associates and joint ventures, are translated into Sterling at rates of exchange ruling at the balance sheet date. The results and cash flows of overseas subsidiaries, associates and joint ventures are translated into Sterling using average rates of exchange.

Exchange adjustments arising when the opening net assets and the profits for the year retained by overseas subsidiaries, associates and joint ventures are translated into Sterling, less exchange differences arising on related foreign currency borrowings which hedge the Group’s net investment in these operations, are taken to a separate component of equity.

When translating into Sterling the assets, liabilities, results and cash flows of overseas subsidiaries, associates and joint ventures which are reported in currencies of hyper-inflationary economies, adjustments are made where material to reflect current price levels. Any loss on net monetary assets is charged to the consolidated income statement.

Revenue

Revenue

Revenue is recognised in the income statement when goods or services are supplied or made available to external customers against orders received, title and risk of loss is passed to the customer, reliable estimates can be made of relevant deductions and all relevant obligations have been fulfilled, such that the earnings process is regarded as being complete.

Turnover represents net invoice value after the deduction of discounts and allowances given and accruals for estimated future rebates and returns. The methodology and assumptions used to estimate rebates and returns are monitored and adjusted regularly in the light of contractual and legal obligations, historical trends, past experience and projected market conditions. Market conditions are evaluated using wholesaler and other third-party analyses, market research data and internally generated information. Value added tax and other sales taxes are excluded from revenue.

Where the Group co-promotes a product and the counterparty records the sale, the Group records its share of revenue as co-promotion income within turnover. The nature of co-promotion activities is such that the Group records no costs of sales. Pharmaceutical turnover includes co-promotion revenue of £16 million (2016 – £9 million; 2015 – £14 million). In addition, initial or event-based milestone income (excluding royalty income) arising on development or marketing collaborations of the Group’s compounds or products with other parties is recognised in turnover. No such income is included in turnover for all the periods presented.

Royalty income is recognised on an accruals basis in accordance with the terms of the relevant licensing agreements.

Expenditure

Expenditure

Expenditure is recognised in respect of goods and services received when supplied in accordance with contractual terms. Provision is made when an obligation exists for a future liability in respect of a past event and where the amount of the obligation can be reliably estimated. Manufacturing start-up costs between validation and the achievement of normal production are expensed as incurred. Advertising and promotion expenditure is charged to the income statement as incurred. Shipment costs on inter-company transfers are charged to cost of sales; distribution costs on sales to customers are included in selling, general and administrative expenditure.

Restructuring costs are recognised and provided for, where appropriate, in respect of the direct expenditure of a business reorganisation where the plans are sufficiently detailed and well advanced, and where appropriate communication to those affected has been undertaken.

Research and development

Research and development

Research and development expenditure is charged to the income statement in the period in which it is incurred. Development expenditure is capitalised when the criteria for recognising an asset are met, usually when a regulatory filing has been made in a major market and approval is considered highly probable. Property, plant and equipment used for research and development is capitalised and depreciated in accordance with the Group’s policy.

Environmental expenditure

Environmental expenditure

Environmental expenditure related to existing conditions resulting from past or current operations and from which no current or future benefit is discernible is charged to the income statement. The Group recognises its liability on a site-by-site basis when it can be reliably estimated. This liability includes the Group’s portion of the total costs and also a portion of other potentially responsible parties’ costs when it is probable that they will not be able to satisfy their respective shares of the clean-up obligation. Recoveries of reimbursements are recorded as assets when virtually certain.

Legal and other disputes

Legal and other disputes

Provision is made for the anticipated settlement costs of legal or other disputes against the Group where an outflow of resources is considered probable and a reliable estimate can be made of the likely outcome. In addition, provision is made for legal or other expenses arising from claims received or other disputes. In respect of product liability claims related to certain products, there is sufficient history of claims made and settlements to enable management to make a reliable estimate of the provision required to cover unasserted claims. In certain cases, an incurred but not reported (IBNR) actuarial technique is used to determine this estimate.

The Group may become involved in legal proceedings, in respect of which it is not possible to make a reliable estimate of the expected financial effect, if any, that could result from ultimate resolution of the proceedings. In these cases, appropriate disclosure about such cases would be included but no provision would be made. Costs associated with claims made by the Group against third parties are charged to the income statement as they are incurred.

Pensions and other post-employment benefits

Pensions and other post-employment benefits

The costs of providing pensions under defined benefit schemes are calculated using the projected unit credit method and spread over the period during which benefit is expected to be derived from the employees’ services, consistent with the advice of qualified actuaries. Pension obligations are measured as the present value of estimated future cash flows discounted at rates reflecting the yields of high quality corporate bonds. Pension scheme assets are measured at fair value at the balance sheet date.

The costs of other post-employment liabilities are calculated in a similar way to defined benefit pension schemes and spread over the period during which benefit is expected to be derived from the employees’ services, in accordance with the advice of qualified actuaries.

Actuarial gains and losses and the effect of changes in actuarial assumptions, are recognised in the statement of comprehensive income in the year in which they arise.

The Group’s contributions to defined contribution plans are charged to the income statement as incurred.

Employee share plans

Employee share plans

Incentives in the form of shares are provided to employees under share option and share award schemes.

The fair values of these options and awards are calculated at their grant dates using a Black-Scholes option pricing model and charged to the income statement over the relevant vesting periods.

The Group provides finance to ESOP Trusts to purchase company shares to meet the obligation to provide shares when employees exercise their options or awards. Costs of running the ESOP Trusts are charged to the income statement. Shares held by the ESOP Trusts are deducted from other reserves. A transfer is made between other reserves and retained earnings over the vesting periods of the related share options or awards to reflect the ultimate proceeds receivable from employees on exercise.

Property, plant and equipment

Property, plant and equipment

Property, plant and equipment (PP&E) is stated at the cost of purchase or construction, less provisions for depreciation and impairment. Financing costs are capitalised within the cost of qualifying assets in construction.

Depreciation is calculated to write off the cost less residual value of PP&E, excluding freehold land, using the straight-line basis over the expected useful life. Residual values and lives are reviewed, and where appropriate adjusted annually. The normal expected useful lives of the major categories of PP&E are:

Freehold buildings	20 to 50 years
Leasehold land and buildings	Lease term or 20 to 50 years
Plant and machinery	10 to 20 years
Equipment and vehicles	3 to 10 years

On disposal of PP&E, the cost and related accumulated depreciation and impairments are removed from the financial statements and the net amount, less any proceeds, is taken to the income statement.

Leases

Leases

Leasing agreements which transfer to the Group substantially all the benefits and risks of ownership of an asset are treated as finance leases, as if the asset had been purchased outright. The assets are included in PP&E or computer software and the capital elements of the leasing commitments are shown as obligations under finance leases. Assets held under finance leases are depreciated on a basis consistent with similar owned assets or the lease term, if shorter. The interest element of the lease rental is included in the income statement. All other leases are operating leases and the rental costs are charged to the income statement on a straight-line basis over the lease term.

Goodwill

Goodwill

Goodwill is stated at cost less impairments. Goodwill is deemed to have an indefinite useful life and is tested for impairment at least annually.

Where the fair value of the interest acquired in an entity’s assets, liabilities and contingent liabilities exceeds the consideration paid, this excess is recognised immediately as a gain in the income statement.

Other intangible assets

Other intangible assets

Intangible assets are stated at cost less provisions for amortisation and impairments.

Licences, patents, know-how and marketing rights separately acquired or acquired as part of a business combination are amortised over their estimated useful lives, generally not exceeding 20 years, using the straight-line basis, from the time they are available for use. The estimated useful lives for determining the amortisation charge take into account patent lives, where applicable, as well as the value obtained from periods of non-exclusivity. Asset lives are reviewed, and where appropriate adjusted, annually. Contingent milestone payments are recognised at the point that the contingent event becomes probable. Any development costs incurred by the Group and associated with acquired licences, patents, know-how or marketing rights are written off to the income statement when incurred, unless the criteria for recognition of an internally generated intangible asset are met, usually when a regulatory filing has been made in a major market and approval is considered highly probable.

Acquired brands are valued independently as part of the fair value of businesses acquired from third parties where the brand has a value which is substantial and long term and where the brands either are contractual or legal in nature or can be sold separately from the rest of the businesses acquired. Brands are amortised over their estimated useful lives of up to 20 years, except where it is considered that the useful economic life is indefinite.

The costs of acquiring and developing computer software for internal use and internet sites for external use are capitalised as intangible fixed assets where the software or site supports a significant business system and the expenditure leads to the creation of a durable asset. ERP systems software is amortised over seven to ten years and other computer software over three to five years.

Impairment of non-current assets

Impairment of non-current assets

The carrying values of all non-current assets are reviewed for impairment, either on a stand-alone basis or as part of a larger cash generating unit, when there is an indication that the assets might be impaired. Additionally, goodwill, intangible assets with indefinite useful lives and intangible assets which are not yet available for use are tested for impairment annually. Any provision for impairment is charged to the income statement in the year concerned.

Impairments of goodwill are not reversed. Impairment losses on other non-current assets are only reversed if there has been a change in estimates used to determine recoverable amounts and only to the extent that the revised recoverable amounts do not exceed the carrying values that would have existed, net of depreciation or amortisation, had no impairments been recognised.

Investments in associates, joint ventures and joint operations

Investments in associates, joint ventures and joint operations

Investments in associates and joint ventures are carried in the consolidated balance sheet at the Group’s share of their net assets at date of acquisition and of their post-acquisition retained profits or losses together with any goodwill arising on the acquisition. The Group recognises its rights to assets, liabilities, revenue and expenses of joint operations.

Available-for-sale investments

Available-for-sale investments

Liquid investments and other investments are classified as available-for-sale investments and are initially recorded at fair value plus transaction costs and then remeasured at subsequent reporting dates to fair value. Unrealised gains and losses on available-for-sale investments are recognised directly in other comprehensive income. Impairments arising from the significant or prolonged decline in fair value of an equity investment reduce the carrying amount of the asset directly and are charged to the income statement.

On disposal or impairment of the investments, any gains and losses that have been deferred in other comprehensive income are reclassified to the income statement. Dividends on equity investments are recognised in the income statement when the Group’s right to receive payment is established. Equity investments are recorded in non-current assets unless they are expected to be sold within one year.

Purchases and sales of equity investments are accounted for on the trade date and purchases and sales of other available-for-sale investments are accounted for on settlement date.

Inventories

Inventories

Inventories are included in the financial statements at the lower of cost (including raw materials, direct labour, other direct costs and related production overheads) and net realisable value. Cost is generally determined on a first in, first out basis. Pre-launch inventory is held as an asset when there is a high probability of regulatory approval for the product. Before that point a provision is made against the carrying value to its recoverable amount; the provision is then reversed at the point when a high probability of regulatory approval is determined.

Trade receivables

Trade receivables

Trade receivables are carried at original invoice amount less any provisions for doubtful debts. Provisions are made where there is evidence of a risk of non-payment, taking into account ageing, previous experience and general economic conditions. When a trade receivable is determined to be uncollectable it is written off, firstly against any provision available and then to the income statement.

Subsequent recoveries of amounts previously provided for are credited to the income statement. Long-term receivables are discounted where the effect is material.

Borrowings

Borrowings

All borrowings are initially recorded at the amount of proceeds received, net of transaction costs. Borrowings are subsequently carried at amortised cost, with the difference between the proceeds, net of transaction costs, and the amount due on redemption being recognised as a charge to the income statement over the period of the relevant borrowing.

Taxation

Taxation

Current tax is provided at the amounts expected to be paid applying tax rates that have been enacted or substantively enacted by the balance sheet date.

Deferred tax is provided in full, on temporary differences arising between the tax bases of assets and liabilities and their carrying amounts in the financial statements. Deferred tax assets are recognised to the extent that it is probable that future taxable profits will be available against which the temporary differences can be utilised. Deferred tax is provided on temporary differences arising on investments in subsidiaries, associates and joint ventures, except where the timing of the reversal of the temporary difference can be controlled and it is probable that the temporary difference will not reverse in the foreseeable future. Deferred tax is provided using rates of tax that have been enacted or substantively enacted by the balance sheet date.

Derivative financial instruments and hedging

Derivative financial instruments and hedging

Derivative financial instruments are used to manage exposure to market risks. The principal derivative instruments used by GSK are foreign currency swaps, interest rate swaps, foreign exchange forward contracts and options. The Group does not hold or issue derivative financial instruments for trading or speculative purposes.

Derivative financial instruments are classified as held-for-trading and are carried in the balance sheet at fair value. Derivatives designated as hedging instruments are classified on inception as cash flow hedges, net investment hedges or fair value hedges.

Changes in the fair value of derivatives designated as cash flow hedges are recognised in other comprehensive income to the extent that the hedges are effective. Ineffective portions are recognised in profit or loss immediately. Amounts deferred in other comprehensive income are reclassified to the income statement when the hedged item affects profit or loss.

Net investment hedges are accounted for in a similar way to cash flow hedges.

Changes in the fair value of derivatives designated as fair value hedges are recorded in the income statement, together with the changes in the fair value of the hedged asset or liability.

Changes in the fair value of any derivative instruments that do not qualify for hedge accounting are recognised immediately in the income statement.

Discounting

Discounting

Where the time value of money is material, balances are discounted to current values using appropriate discount rates. The unwinding of the discounts is recorded in finance income and finance expense.

XML

Accounting principles and policies (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Expected Useful Lives of Property Plant and Equipment

The normal expected useful lives of the major categories of PP&E are:

Freehold buildings	20 to 50 years
Leasehold land and buildings	Lease term or 20 to 50 years
Plant and machinery	10 to 20 years
Equipment and vehicles	3 to 10 years

XML

Exchange rates (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Currencies Translations and Relevant Exchange Rates

The currencies which most influence these translations and the relevant exchange rates were as follows:

	2017		2016		2015
Average rates:
US$/£		1.30		1.36		1.53
Euro/£		1.15		1.23		1.37
Yen/£		145		149		185
Period end rates:
US$/£		1.35		1.24		1.47
Euro/£		1.13		1.17		1.36
Yen/£		152		144		177

XML

Segment information (Tables)

12 Months Ended

Dec. 31, 2017

Turnover by Segment

	2017		2016		2015
Turnover by segment	£m		£m		£m
Pharmaceuticals		17,276		16,104		14,157
Vaccines		5,160		4,592		3,656
Consumer Healthcare		7,750		7,193		6,038
Segment turnover		30,186		27,889		23,851
Corporate and other unallocated turnover		–		–		72
		30,186		27,889		23,923

Segment Profit and Operating Profit

	2017			2016 (revised)			2015 (revised)
Segment profit	£m			£m			£m
Pharmaceuticals		8,667			7,976			6,449
Pharmaceuticals R&D		(2,740	)		(2,488	)		(2,168	)
Pharmaceuticals, including R&D		5,927			5,488			4,281
Vaccines		1,644			1,429			958
Consumer Healthcare		1,373			1,116			684
Segment profit		8,944			8,033			5,923
Corporate and other unallocated costs		(376	)		(362	)		(264	)
Other reconciling items between segment profit and operating profit		(4,481	)		(5,073	)		4,663
Operating profit		4,087			2,598			10,322
Finance income		65			72			104
Finance costs		(734	)		(736	)		(757	)
Profit on disposal of interest in associates		94			–			843
Share of after tax profits of associates and joint ventures		13			5			14
Profit before taxation		3,525			1,939			10,526
Taxation		(1,356	)		(877	)		(2,154	)
Profit after taxation for the year		2,169			1,062			8,372

Depreciation and amortisation by segment	2017 £m		2016 £m		2015 £m
Pharmaceuticals		551		440		303
Pharmaceuticals R&D		96		211		238
Pharmaceuticals, including R&D		647		651		541
Vaccines		405		315		253
Consumer Healthcare		135		126		140
Segment depreciation and amortisation		1,187		1,092		934
Corporate and other unallocated depreciation and amortisation		144		94		145
Other reconciling items between segment depreciation and amortisation and total depreciation and amortisation		591		588		551
Total depreciation and amortisation		1,922		1,774		1,630

PP&E, intangible asset and goodwill impairment by segment	2017 £m		2016 £m		2015 £m
Pharmaceuticals		38		29		57
Pharmaceuticals R&D		10		88		105
Pharmaceuticals, including R&D		48		117		162
Vaccines		13		34		17
Consumer Healthcare		10		46		5
Segment impairment		71		197		184
Corporate and other unallocated impairment		3		24		18
Other reconciling items between segment impairment and total impairment		995		68		385
Total impairment		1,069		289		587

PP&E and intangible asset impairment reversals by segment	2017 £m			2016 £m			2015 £m
Pharmaceuticals		(13	)		(15	)		(8	)
Pharmaceuticals R&D		(2	)		(10	)		(10	)
Pharmaceuticals, including R&D		(15	)		(25	)		(18	)
Vaccines		–			(19	)		–
Consumer Healthcare		(1	)		(8	)		(4	)
Segment impairment reversals		(16	)		(52	)		(22	)
Corporate and other unallocated impairment reversals		–			(26	)		(2	)
Other reconciling items between segment impairment reversals and total impairment reversals		(36	)		(9	)		–
Total impairment reversals		(52	)		(87	)		(24	)

	2017			2016
Net assets by segment	£m			£m
Pharmaceuticals		2,017			3,225
Pharmaceuticals R&D		522			572
Pharmaceuticals, including R&D		2,539			3,797
Vaccines		9,707			9,676
Consumer Healthcare		2,003			3,721
Segment net operating assets		14,249			17,194
Corporate and other unallocated net operating assets		868			(228	)
Net operating assets		15,117			16,966
Net debt		(13,178	)		(13,804	)
Investments in associates and joint ventures		183			263
Derivative financial instruments		2			(38	)
Current and deferred taxation		1,252			1,361
Assets held for sale		113			215
Net assets		3,489			4,963

Summary of Geographical Information

Geographical information

The UK is regarded as being the Group’s country of domicile.

Turnover by location of customer	2017 £m		2016 £m		2015 £m
UK		940		1,056		1,102
US		11,263		10,197		8,222
International		17,983		16,636		14,599
External turnover		30,186		27,889		23,923
			2017		2016
Non-current assets by location of subsidiary			£m		£m
UK				6,824		7,060
US				6,841		7,802
International				20,901		21,234
Non-current assets				34,566		36,096

Pharmaceuticals [member]

Turnover by Product & Service

	2017		2016		2015
Pharmaceuticals turnover by therapeutic area	£m		£m		£m
Respiratory		6,991		6,510		5,741
HIV		4,350		3,556		2,322
Immuno-inflammation		377		340		263
Established Pharmaceuticals		5,558		5,698		5,831
		17,276		16,104		14,157

Consumer Healthcare [member]

Turnover by Product & Service

		2017		2016		2015
Consumer Healthcare turnover by category	£m		£m		£m
Wellness		4,001		3,726		2,970
Oral care		2,466		2,223		1,875
Nutrition		680		674		684
Skin health		603		570		509
		7,750		7,193		6,038

Vaccines [member]

Turnover by Product & Service

	2017		2016		2015
Vaccines turnover by category	£m		£m		£m
Meningitis		890		662		326
Influenza		488		414		268
Shingles		22		–		–
Established Vaccines		3,760		3,516		3,062
		5,160		4,592		3,656

XML

Other operating income/(expense) (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary Information about Other Operating Income Expense

	2017			2016			2015
	£m			£m			£m
Impairment of equity investments		(30	)		(47	)		(263	)
Disposal of equity investments		37			254			342
Disposal of businesses and assets		195			283			9,661
Fair value remeasurements on contingent consideration recognised in business combinations		(1,012	)		(2,205	)		(1,965	)
Remeasurement of ViiV Healthcare put option liabilities and preferential dividends		13			(577	)		–
Remeasurement of Consumer Healthcare put option liability		(1,186	)		(1,133	)		(83	)
Fair value adjustments on derivative financial instruments		9			(3	)		2
Other income/(expense)		9			23			21
		(1,965	)		(3,405	)		7,715

XML

Operating profit (Tables)

12 Months Ended

Dec. 31, 2017

Summary of Information About Profit Loss

	2017			2016			2015
The following items have been included in operating profit:	£m			£m			£m
Employee costs (Note 9)		9,122			8,212			8,030
Advertising		1,351			1,265			1,059
Distribution costs		405			395			376
Depreciation of property, plant and equipment		988			978			892
Impairment of property, plant and equipment, net of reversals		327			180			346
Amortisation of intangible assets		934			796			738
Impairment of intangible assets, net of reversals		690			22			217
Net foreign exchange losses		215			53			47
Inventories:
Cost of inventories included in cost of sales		8,526			8,093			7,602
Write-down of inventories		701			533			488
Reversal of prior year write-down of inventories		(352	)		(145	)		(65	)
Operating lease rentals:
Minimum lease payments		110			91			101
Contingent rents		4			4			8
Sub-lease payments		5			4			7
Fees payable to the company’s auditor and its associates in relation to the Group (see below)		29.2			29.7			33.1

Summary of Auditors Remuneration

Fees payable to the company’s auditor and its associates:	2017 £m		2016 £m		2015 £m
Audit of parent company and consolidated financial statements		7.0		5.8		7.5
Audit of the company’s subsidiaries		16.2		16.4		16.3
Attestation under s.404 of Sarbanes-Oxley Act 2002		4.5		4.4		4.3
Audit and audit-related services		27.7		26.6		28.1
Taxation compliance		0.2		0.2		0.3
Taxation advice		0.1		1.8		3.2
Other assurance services		1.0		0.3		1.1
All other services		0.2		0.8		0.4
		29.2		29.7		33.1

Pension schemes [member]

Summary of Auditors Remuneration

In addition to the above, fees paid in respect of the GSK pension schemes were:

	2017 £m		2016 £m		2015 £m
Audit		0.3		0.4		0.3
Other services		0.1		—		—

XML

Employee costs (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Employee Costs

	2017		2016		2015
	£m		£m		£m
Wages and salaries		7,116		6,391		6,132
Social security costs		802		733		633
Pension and other post-employment costs, including augmentations (Note 28)		616		541		467
Cost of share-based incentive plans		347		338		349
Severance and other costs from integration and restructuring activities		241		209		449
		9,122		8,212		8,030

Disclosure of Average Monthly Number of Persons Employed by the Group (Including Directors)

The average monthly number of persons employed by the Group (including Directors) during the year was:

	2017 Number		2016 Number		2015 Number
Manufacturing		38,632		38,611		37,025
Selling, general and administration		49,141		49,961		52,121
Research and development		11,576		11,255		12,046
		99,349		99,827		101,192

Summary of Compensation of the Directors and Senior Management

The compensation of the Directors and Senior Management (members of the CET) in aggregate, was as follows:

	2017 £m		2016 £m		2015 £m
Wages and salaries		26		25		23
Social security costs		4		4		2
Pension and other post-employment costs		3		2		3
Cost of share-based incentive plans		22		15		18
		55		46		46

XML

Pensions and other post-employment benefits (Tables)

12 Months Ended

Dec. 31, 2017

Summary of Analysis of Defined Benefit Pension Obligation

	2017		2016		2015
Pension and other post-employment costs	£m		£m		£m
UK pension schemes		198		205		177
US pension schemes		113		106		96
Other overseas pension schemes		218		140		135
Unfunded post-retirement healthcare schemes		87		90		59
		616		541		467
Analysed as:
Funded defined benefit/hybrid pension schemes		335		304		291
Unfunded defined benefit pension schemes		55		43		36
Unfunded post-retirement healthcare schemes		87		90		59
Defined benefit schemes		477		437		386
Defined contribution pension schemes		139		104		81
		616		541		467

Summary of Average Life Expectancy Assumed

The average life expectancy assumed now for an individual at the age of 60 and projected to apply in 2037 for an individual then at the age of 60 is as follows:

	UK				US
	Male Years		Female Years		Male Years		Female Years
Current		27.5		29.5		26.9		28.6
Projected for 2037		29.1		31.1		28.6		30.3

Summary of Financial Assumptions in Assessing Defined Benefit Liabilities

The Group has applied the following financial assumptions in assessing the defined benefit liabilities:

	UK						US						Rest of World
	2017 % pa		2016 % pa		2015 % pa		2017 % pa		2016 % pa		2015 % pa		2017 % pa		2016 % pa		2015 % pa
Rate of increase of future earnings		2.00		2.00		2.00		4.00		4.00		4.00		2.80		2.70		2.70
Discount rate		2.50		2.70		3.80		3.60		3.90		4.20		1.60		1.60		2.20
Expected pension increases		3.20		3.20		3.10		n/a		n/a		n/a		2.20		2.10		2.00
Cash balance credit/conversion rate		n/a		n/a		n/a		2.90		3.20		3.20		0.30		0.30		0.60
Inflation rate		3.20		3.20		3.10		2.25		2.25		2.25		1.70		1.50		1.40

Summary of Amounts Recorded in Income Statement and Statement of Comprehensive Income Related to Defined Benefit Pension and Post-retirement Healthcare Schemes

The amounts recorded in the income statement and statement of comprehensive income for the three years ended 31 December 2017 in relation to the defined benefit pension and post-retirement healthcare schemes were as follows:

	Pensions												Post-retirement benefits
2017	UK £m			US £m			Rest of World £m			Group £m			Group £m
Amounts charged to operating profit
Current service cost		79			70			131			280			30
Past service cost		37			—			—			37			(2	)
Net interest cost		7			31			16			54			59
Expenses		7			12			—			19			—
		130			113			147			390			87
Remeasurement gains/(losses) recorded in the statement of comprehensive income		259			240			(14	)		485			64
	Pensions												Post-retirement benefits
2016	UK £m			US £m			Rest of World £m			Group £m			Group £m
Amounts charged to operating profit
Current service cost		70			66			110			246			31
Past service cost		52			1			1			54			3
Net interest cost		9			27			20			56			56
Gains from settlements		—			—			(28	)		(28	)		—
Expenses		7			12			—			19			—
		138			106			103			347			90
Remeasurement losses recorded in the statement of comprehensive income		(165	)		(27	)		(224	)		(416	)		(59	)
	Pensions												Post-retirement benefits
2015	UK £m			US £m			Rest of World £m			Group £m			Group £m
Amounts charged to operating profit
Current service cost		77			67			110			254			22
Past service cost/(credit)		25			2			(10	)		17			(8	)
Net interest cost		14			22			13			49			52
Losses/(gains) from settlements		—			1			(9	)		(8	)		(7	)
Expenses		7			4			4			15			—
		123			96			108			327			59
Remeasurement gains/(losses) recorded in the statement of comprehensive income		82			(30	)		147			199			62

Summary of Balance Sheet Presentation of Group Defined Benefit Pension Schemes and Other Post-retirement Benefits

A summarised balance sheet presentation of the Group defined benefit pension schemes and other post-retirement benefits is set out in the table below:

	2017			2016			2015
	£m			£m			£m
Recognised in Other non-current assets:
Pension schemes in surplus		538			313			258
Recognised in Pensions and other post-employment benefits:
Pension schemes in deficit		(2,043	)		(2,397	)		(1,842	)
Post-retirement benefits		(1,496	)		(1,693	)		(1,387	)
		(3,539	)		(4,090	)		(3,229	)

Summary of Fair Values of Assets and Liabilities of UK and US Defined Benefit Pension Schemes Together with Aggregated Data for Other Defined Benefit Pension Schemes in Group

The fair values of the assets and liabilities of the UK and US defined benefit pension schemes, together with aggregated data for other defined benefit pension schemes in the Group are as follows:

		UK			US			Rest of World			Group
At 31 December 2017		£m			£m			£m			£m
Equities:	– listed		4,902			1,448			544			6,894
	– unlisted		—			—			13			13
Multi-asset funds			2,517			—			—			2,517
Property:	– unlisted		352			209			32			593
Corporate bonds:	– listed		297			820			103			1,220
	– unlisted		326			—			20			346
Government bonds:	– listed		5,127			239			762			6,128
Insurance contracts			849			—			707			1,556
Other assets			(1,216	)		158			71			(987	)
Fair value of assets			13,154			2,874			2,252			18,280
Present value of scheme obligations			(13,101	)		(3,445	)		(3,239	)		(19,785	)
Net surplus/(obligation)			53			(571	)		(987	)		(1,505	)
Included in Other non-current assets			470			—			68			538
Included in Pensions and other post-employment benefits			(417	)		(571	)		(1,055	)		(2,043	)
			53			(571	)		(987	)		(1,505	)
Actual return on plan assets			893			394			82			1,369

The multi-asset funds comprise investments in pooled investment vehicles that are invested across a range of asset classes, increasing diversification within the growth portfolio.

The index-linked gilts held as part of the UK repo programme are included in government bonds. The related loan is included within ‘Other assets’ at a value of £(773) million (2016 – £(1,698) million; 2015 – £(2,215) million).

		UK			US			Rest of World			Group
At 31 December 2016		£m			£m			£m			£m
Equities:	– listed		5,357			1,358			486			7,201
	– unlisted		—			—			14			14
Multi-asset funds			1,545			—			—			1,545
Property:	– unlisted		314			216			28			558
Corporate bonds:	– listed		292			213			96			601
	– unlisted		321			—			24			345
Government bonds:	– listed		6,165			815			739			7,719
Insurance contracts			856			—			637			1,493
Other assets			(2,267	)		288			73			(1,906	)
Fair value of assets			12,583			2,890			2,097			17,570
Present value of scheme obligations			(12,884	)		(3,752	)		(3,018	)		(19,654	)
Net obligation			(301	)		(862	)		(921	)		(2,084	)
Included in Other non-current assets			276			—			37			313
Included in Pensions and other post-employment benefits			(577	)		(862	)		(958	)		(2,397	)
			(301	)		(862	)		(921	)		(2,084	)
Actual return on plan assets			2,473			153			99			2,725

At 31 December 2015		UK £m			US £m			Rest of World £m			Group £m
Equities:	– listed		5,187			1,235			355			6,777
	– unlisted		—			—			1			1
Multi-asset funds			481			—			—			481
Property:	– unlisted		302			175			8			485
Corporate bonds:	– listed		251			727			76			1,054
	– unlisted		232			—			2			234
Government bonds:	– listed		5,687			184			664			6,535
Insurance contracts			755			—			439			1,194
Other assets			(2,611	)		180			205			(2,226	)
Fair value of assets			10,284			2,501			1,750			14,535
Present value of scheme obligations			(10,601	)		(3,134	)		(2,384	)		(16,119	)
Net obligation			(317	)		(633	)		(634	)		(1,584	)
Included in Other non-current assets			232			—			26			258
Included in Pensions and other post-employment benefits			(549	)		(633	)		(660	)		(1,842	)
			(317	)		(633	)		(634	)		(1,584	)
Actual return on plan assets			(17	)		(30	)		23			(24	)

Summary of Movements in Fair Values of Assets

													Post-retirement
	Pensions												benefits
	UK			US			Rest of World			Group			Group
Movements in fair values of assets	£m			£m			£m			£m			£m
Assets at 1 January 2015		10,551			2,531			1,529			14,611			—
Exchange adjustments		—			147			(52	)		95			—
Additions through business combinations		—			—			233			233			—
Interest income		374			95			33			502			—
Expenses		(7	)		(4	)		(4	)		(15	)		—
Settlements and curtailments		—			—			(16	)		(16	)		—
Remeasurement		(391	)		(125	)		(10	)		(526	)		—
Employer contributions		164			132			112			408			82
Scheme participants’ contributions		4			—			14			18			14
Benefits paid		(411	)		(275	)		(89	)		(775	)		(96	)
Assets at 31 December 2015		10,284			2,501			1,750			14,535			—
Exchange adjustments		—			459			305			764			—
Interest income		385			108			37			530			—
Expenses		(7	)		(12	)		—			(19	)		—
Settlements and curtailments		—			—			(110	)		(110	)		—
Remeasurement		2,088			45			62			2,195			—
Employer contributions		319			31			131			481			91
Scheme participants’ contributions		4			—			14			18			17
Benefits paid		(490	)		(242	)		(92	)		(824	)		(108	)
Assets at 31 December 2016		12,583			2,890			2,097			17,570			—
Exchange adjustments		—			(244	)		24			(220	)		—
Interest income		333			104			33			470			—
Expenses		(7	)		(12	)		—			(19	)		—
Settlements and curtailments		—			—			(4	)		(4	)		—
Remeasurement		560			290			49			899			—
Employer contributions		225			103			116			444			101
Scheme participants’ contributions		4			—			17			21			17
Benefits paid		(544	)		(257	)		(80	)		(881	)		(118	)
Assets at 31 December 2017		13,154			2,874			2,252			18,280			—

Summary of Movements in Defined Benefit Obligations

													Post-retirement
	Pensions												benefits
	UK			US			Rest of World			Group			Group
Movements in defined benefit obligations	£m			£m			£m			£m			£m
Obligations at 1 January 2015		(10,991	)		(3,133	)		(2,176	)		(16,300	)		(1,397	)
Exchange adjustments		—			(184	)		78			(106	)		(64	)
Additions through business combinations		—			—			(397	)		(397	)		(11	)
Service cost		(77	)		(67	)		(110	)		(254	)		(22	)
Past service cost		(25	)		(2	)		10			(17	)		8
Interest cost		(388	)		(117	)		(46	)		(551	)		(52	)
Settlements and curtailments		—			(1	)		25			24			7
Remeasurement		473			95			157			725			62
Scheme participants’ contributions		(4	)		—			(14	)		(18	)		(14	)
Benefits paid		411			275			89			775			96
Obligations at 31 December 2015		(10,601	)		(3,134	)		(2,384	)		(16,119	)		(1,387	)
Exchange adjustments		—			(586	)		(396	)		(982	)		(248	)
Service cost		(70	)		(66	)		(110	)		(246	)		(31	)
Past service cost		(52	)		(1	)		(1	)		(54	)		(3	)
Interest cost		(394	)		(135	)		(57	)		(586	)		(56	)
Settlements and curtailments		—			—			138			138			—
Remeasurement		(2,253	)		(72	)		(286	)		(2,611	)		(59	)
Scheme participants’ contributions		(4	)		—			(14	)		(18	)		(17	)
Benefits paid		490			242			92			824			108
Obligations at 31 December 2016		(12,884	)		(3,752	)		(3,018	)		(19,654	)		(1,693	)
Exchange adjustments		—			305			(45	)		260			119
Service cost		(79	)		(70	)		(131	)		(280	)		(30	)
Past service cost		(37	)		—			—			(37	)		2
Interest cost		(340	)		(135	)		(49	)		(524	)		(59	)
Settlements and curtailments		—			—			4			4			—
Remeasurement		(301	)		(50	)		(63	)		(414	)		64
Scheme participants’ contributions		(4	)		—			(17	)		(21	)		(17	)
Benefits paid		544			257			80			881			118
Obligations at 31 December 2017		(13,101	)		(3,445	)		(3,239	)		(19,785	)		(1,496	)

Summary of Net Defined Benefit Liability

The movement in the net defined benefit liability is as follows:

	2017			2016			2015
	£m			£m			£m
At 1 January		(2,084	)		(1,584	)		(1,689	)
Exchange adjustments		40			(218	)		(11	)
Additions through business combinations		—			—			(164	)
Service cost		(280	)		(246	)		(254	)
Past service cost		(37	)		(54	)		(17	)
Interest cost		(54	)		(56	)		(49	)
Settlements and curtailments		—			28			8
Remeasurements:
Return on plan assets, excluding amounts included in interest		899			2,195			(526	)
Gain from change in demographic assumptions		209			85			120
(Loss)/gain from change in financial assumptions		(555	)		(2,770	)		362
Experience (losses)/gains		(68	)		74			243
Employer contributions		444			481			408
Expenses/other movements		(19	)		(19	)		(15	)
At 31 December		(1,505	)		(2,084	)		(1,584	)

Summary of Defined Benefit Pension Obligation Analysed by Membership Category

The defined benefit pension obligation analysed by membership category is as follows:

	2017 £m		2016 £m		2015 £m
Active		4,611		4,576		5,510
Retired		9,805		9,574		7,969
Deferred		5,369		5,504		4,231
		19,785		19,654		17,710

Summary of Post-Retirement Benefit Obligation Analysed By Membership Category

The post-retirement benefit obligation analysed by membership category is as follows:
	2017 £m		2016 £m		2015 £m
Active		514		594		499
Retired		981		1,099		887
Deferred		1		—		1
		1,496		1,693		1,387

Summary of Weighted Average Duration of Defined Benefit Obligation

	2017 £m		2016 £m		2015 £m
Active		4,611		4,576		5,510
Retired		9,805		9,574		7,969
Deferred		5,369		5,504		4,231
		19,785		19,654		17,710
The post-retirement benefit obligation analysed by membership category is as follows:
	2017 £m		2016 £m		2015 £m
Active		514		594		499
Retired		981		1,099		887
Deferred		1		—		1
		1,496		1,693		1,387
The weighted average duration of the defined benefit obligation is as follows:
	2017 years		2016 years		2015 years
Pension benefits		16		16		16
Post-retirement benefits		11		12		12

Summary of Changes In Assumptions Used on Benefit Obligations, Defined Benefit Pension and Post Retirement Costs

Effect of changes in assumptions used on the benefit obligations and on the 2018 annual defined benefit pension and post retirement costs.

	£m
A 0.25% decrease in discount rate would have the following approximate effect:
Increase in annual pension cost		29
Decrease in annual post-retirement benefits cost		(1	)
Increase in pension obligation		800
Increase in post-retirement benefits obligation		41
A one year increase in life expectancy would have the following approximate effect:
Increase in annual pension cost		20
Increase in annual post-retirement benefits cost		2
Increase in pension obligation		608
Increase in post-retirement benefits obligation		39
A 1% increase in the rate of future healthcare inflation would have the following approximate effect:
Increase in annual post-retirement benefits cost		2
Increase in post-retirement benefits obligation		68
A 0.25% increase in inflation would have the following approximate effect:
Increase in annual pension cost		19
Increase in pension obligation		502

Share-based Incentive Plans [Member]

Summary of Analysis of Defined Benefit Pension Obligation

The cost of share-based incentive plans is analysed as follows:

	2017 £m		2016 £m		2015 £m
Share Value Plan		276		271		307
Performance Share Plan		47		39		26
Share option plans		4		4		4
Cash settled and other plans		20		24		12
		347		338		349

Defined benefit pension and post-retirement healthcare scheme. [member]

Summary of Analysis of Defined Benefit Pension Obligation

The costs of the defined benefit pension and post-retirement healthcare schemes are charged in the income statement as follows:

	2017		2016		2015
	£m		£m		£m
Cost of sales		162		135		127
Selling, general and administration		238		221		194
Research and development		77		81		65
		477		437		386

Defined Benefit Pension Obligation [Member]

Summary of Analysis of Defined Benefit Pension Obligation

The defined benefit pension obligation is analysed as follows:

	2017			2016			2015
	£m			£m			£m
Funded		(19,052	)		(18,974	)		(15,552	)
Unfunded		(733	)		(680	)		(567	)
		(19,785	)		(19,654	)		(16,119	)

Post-retirement benefits [member]

Summary of Net Defined Benefit Liability

	2017			2016			2015
	£m			£m			£m
At 1 January		(2,084	)		(1,584	)		(1,689	)
Exchange adjustments		40			(218	)		(11	)
Additions through business combinations		—			—			(164	)
Service cost		(280	)		(246	)		(254	)
Past service cost		(37	)		(54	)		(17	)
Interest cost		(54	)		(56	)		(49	)
Settlements and curtailments		—			28			8
Remeasurements:
Return on plan assets, excluding amounts included in interest		899			2,195			(526	)
Gain from change in demographic assumptions		209			85			120
(Loss)/gain from change in financial assumptions		(555	)		(2,770	)		362
Experience (losses)/gains		(68	)		74			243
Employer contributions		444			481			408
Expenses/other movements		(19	)		(19	)		(15	)
At 31 December		(1,505	)		(2,084	)		(1,584	)
The remeasurements included within post-retirement benefits are detailed below:
	2017			2016			2015
	£m			£m			£m
Gain from change in demographic assumptions		47			—			15
(Loss)/gain from change in financial assumptions		(1	)		(81	)		59
Experience gains/(losses)		18			22			(12	)
		64			(59	)		62

XML

Major restructuring costs (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Costs Charged to Operating Profit

The costs charged to operating profit under these programmes were as follows:

	2017 £m			2016 £m			2015 £m
Increase in provision for major restructuring programmes (see Note 29)		259			163			718
Amount of provision reversed unused (see Note 29)		(43	)		(140	)		(44	)
Impairment losses recognised		278			158			419
Other non-cash charges		247			108			51
Other cash costs		315			681			747
		1,056			970			1,891

XML

Finance income (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Interest Income

	2017		2016		2015
	£m		£m		£m
Interest income arising from:
cash and cash equivalents		60		67		71
available-for-sale investments		2		1		1
derivatives at fair value through profit or loss		—		—		24
loans and receivables		1		2		3
Fair value adjustments on derivatives at fair value through profit or loss		2		2		5
		65		72		104

XML

Finance expense (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Finance Cost

	2017			2016			2015
	£m			£m			£m
Interest expense arising on:
financial liabilities at amortised cost		(698	)		(671	)		(655	)
derivatives at fair value through profit or loss		(22	)		(30	)		(64	)
Fair value movements on other derivatives at fair value through profit or loss		(4	)		(3	)		(6	)
Reclassification of cash flow hedge from other comprehensive income		—			(1	)		(2	)
Unwinding of discounts on provisions		(16	)		(16	)		(16	)
Other finance expense		6			(15	)		(14	)
		(734	)		(736	)		(757	)

XML

Associates and joint ventures (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of After Tax Profits and Losses of Associates and Joint Ventures

The Group’s share of after tax profits and losses of associates and joint ventures is set out below:

	2017 £m			2016 £m			2015 £m
Share of after tax profits of associates		16			9			16
Share of after tax losses of joint ventures		(3	)		(4	)		(2	)
		13			5			14

Summary of Group Held for Significant Associate

Summarised income statement information in respect of Innoviva is set out below for the periods in which the Group accounted for its investment in Innoviva as an associate. The Group’s 2017 share of after tax profits of associates and other comprehensive income includes a profit of £18 million and other comprehensive income of £nil in respect of Innoviva.

					Since
					1 September
	2017		2016		2015
	£m		£m		£m
Turnover		165		98		20
Profit after taxation		103		44		4
Other comprehensive income		—		—		—
Total comprehensive income		103		44		4

Summary of Aggregated Financial Information

Aggregated financial information in respect of GSK’s share of other associated undertakings and joint ventures is set out below:

	2017 £m			2016 £m			2015 £m
Share of turnover		252			133			188
Share of after tax (losses)/profits		(5	)		(1	)		12
Share of other comprehensive income		—			—			25
Share of total comprehensive (expense)/income		(5	)		(1	)		37

XML

Taxation (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Taxation Charge Based on Profits

Taxation charge based on profits for the year	2017 £m			2016 £m			2015 £m
UK current year charge		199			241			156
Rest of World current year charge		1,928			1,326			2,924
Credit in respect of prior periods		(508	)		(149	)		(508	)
Total current taxation		1,619			1,418			2,572
Total deferred taxation		(263	)		(541	)		(418	)
Total tax		1,356			877			2,154

Summary of Reconciliation of Tax Charge Calculated at the UK Statutory Rate on the Group Profit Before Tax with the Actual Tax Charge

The following table reconciles the tax charge calculated at the UK statutory rate on the Group profit before tax with the actual tax charge for the year.

Reconciliation of taxation on Group profits	2017 £m			2017 %			2016 £m			2016 %			2015 £m			2015 %
Profit before tax		3,525						1,939						10,526
UK statutory rate of taxation		679			19.25			388			20.0			2,131			20.25
Differences in overseas taxation rates		635			18.0			593			30.6			1,035			9.8
Benefit of intellectual property incentives		(458	)		(13.0	)		(321	)		(16.5	)		(286	)		(2.7	)
R&D credits		(75	)		(2.1	)		(93	)		(4.8	)		(38	)		(0.4	)
Remeasurement of non-taxable put option liabilities		227			6.4			340			17.5			17			0.2
Losses not recognised/(previously unrecognised losses)		28			0.8			(15	)		(0.8	)		31			0.3
Permanent differences on disposals and acquisitions		4			0.1			(21	)		(1.1	)		(248	)		(2.4	)
Other permanent differences		196			5.6			97			5.0			58			0.6
Reassessment of prior year estimates in respect of current and deferred taxes		(475	)		(13.5	)		(116	)		(6.0	)		(578	)		(5.5	)
US and Swiss tax reform		595			16.9
Tax on unremitted earnings		—			—			25			1.3			32			0.3
Tax charge/tax rate		1,356			38.5			877			45.2			2,154			20.5

Summary of Tax on Items Charged to Equity and Statement of Comprehensive Income

Future tax charges, and therefore the Group’s effective tax rate, may be affected by factors such as acquisitions, disposals, restructurings, the location of research and development activity, tax regime reforms and resolution of open matters as we continue to bring our tax affairs up to date around the world.

	2017			2016		2015
Tax on items charged to equity and statement of comprehensive income	£m			£m		£m
Current taxation
Share-based payments		—			7		22
Defined benefit plans		26			32		30
		26			39		52
Deferred taxation
Share-based payments		(4	)		—		(12	)
Defined benefit plans		(247	)		94		(110	)
Exchange movements		—			—		—
Fair value movements on cash flow hedges		—			2		—
Fair value movements on available-for-sale investments		29			51		(55	)
		(222	)		147		(177	)
Total (charge)/credit to equity and statement of comprehensive income		(196	)		186		(125	)

Impact of Tax Reform on Profits Attributable to Shareholders

The impact of tax reform on profits attributable to shareholders in 2017 is set out below.

	Swiss tax		US tax
	reform		reform
	£m		£m
Other operating expenses		—		(666	)
Current tax		—		(273	)
Deferred tax		483		(805	)
Impact on profit after taxation for the year		483		(1,744	)
Profit attributable to non-controlling interests		176		(114	)
Profit attributable to shareholders		307		(1,630	)

Impact on Tax Charge Arising From US Tax Reform

The impact on the tax charge arising from US tax reform was as follows:

	Current tax			Deferred tax			Total
	£m			£m			£m
Revaluation of assets and liabilities		75			(805	)		(730	)
Repatriation tax		(348	)		—			(348	)
		(273	)		(805	)		(1,078	)

Summary of Movement in Deferred Tax Assets and Liabilities

Movement in deferred tax assets and liabilities

													Pensions &						Share			Other
	Accelerated												other post						option			net
	capital			Intangible			Contingent			Intra-Group			employment			Tax			and award			temporary
	allowances			assets			consideration			profit			benefits			losses			schemes			differences			Total
	£m			£m			£m			£m			£m			£m			£m			£m			£m
At 1 January 2017		(377	)		(2,324	)		1,138			1,054			1,262			227			110			1,350			2,440
Exchange adjustments		(7	)		75			—			(58	)		(48	)		(5	)		(4	)		(18	)		(65	)
Credit/(charge) to income statement		62			330			(52	)		256			3			59			(1	)		(88	)		569
Credit/(charge) to income statement associated with US tax reform		5			116			(218	)		(235	)		(210	)		(20	)		(27	)		(216	)		(805	)
Credit to income statement associated with Swiss tax reform		—			483			—			—			—			—			—			—			483
(Charge)/credit to statement of comprehensive income and equity		—			—			—			—			(247	)		—			(4	)		29			(222	)
At 31 December 2017		(317	)		(1,320	)		868			1,017			760			261			74			1,057			2,400

Summary of Net Temporary Differences Include Accrued Expenses

Deferred tax assets and liabilities are recognised on the balance sheet as follows:

	2017			2016
	£m			£m
Deferred tax assets		3,796			4,374
Deferred tax liabilities		(1,396	)		(1,934	)
		2,400			2,440

Summary of Temporary Difference Unused Tax Losses and Unused Tax Credits

Deferred tax assets are recognised where it is probable that future taxable profit will be available to utilise losses. Unrecognised tax losses are as follows:

	2017				2016
			Unrecognised				Unrecognised
			deferred tax				deferred tax
	Tax losses		asset		Tax losses		asset
Unrecognised tax losses	£m		£m		£m		£m
Trading losses expiring:
Within 10 years		802		187		786		255
More than 10 years		872		99		842		131
Available indefinitely		86		14		95		15
At 31 December		1,760		300		1,723		401
Capital losses		1,924		372		2,320		396
At 31 December		1,924		372		2,320		396

XML

Earnings per share (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Basic and Diluted Earnings Per Share

	2017		2016		2015
	pence		pence		pence
Basic earnings per share		31.4		18.8		174.3
Diluted earnings per share		31.0		18.6		172.3

Schedule of Numbers of Shares Earnings Per Share

The numbers of shares used in calculating basic and diluted earnings per share are reconciled below.

	2017		2016		2015
Weighted average number of shares in issue	millions		millions		millions
Basic		4,886		4,860		4,831
Dilution for share options and awards		55		49		57
Diluted		4,941		4,909		4,888

XML

Dividends (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Interim Financial Reporting

	2017						2016						2015
			Dividend		Total				Dividend		Total				Dividend		Total
			per share		dividend				per share		dividend				per share		dividend
	Paid/payable		(pence)		£m		Paid		(pence)		£m		Paid		(pence)		£m
First interim		13 July 2017		19		928		14 July 2016		19		923		9 July 2015		19		920
Second interim		12 October 2017		19		929		13 October 2016		19		925		1 October 2015		19		919
Third interim		11 January 2018		19		929		12 January 2017		19		925		14 January 2016		19		919
Fourth interim		12 April 2018		23		1,125		13 April 2017		23		1,124		14 April 2016		23		1,114
Total				80		3,911				80		3,897				80		3,872
Special dividend														14 April 2016		20		969

Summary of Dividends to Shareholders

The amounts recognised in each year were as follows:

	2017		2016		2015
	£m		£m		£m
Dividends to shareholders		3,906		4,850		3,874

XML

Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Property, Plant and Equipment

				Plant,
	Land and			equipment			Assets in
	buildings			and vehicles			construction			Total
	£m			£m			£m			£m
Cost at 1 January 2016		7,305			10,775			2,670			20,750
Exchange adjustments		956			1,100			271			2,327
Other additions		117			384			1,043			1,544
Capitalised borrowing costs		—			—			30			30
Disposals and write-offs		(349	)		(1,422	)		(53	)		(1,824	)
Reclassifications		110			512			(761	)		(139	)
Transfer to assets held for sale		(378	)		(114	)		(32	)		(524	)
Cost at 31 December 2016		7,761			11,235			3,168			22,164
Exchange adjustments		(127	)		(62	)		(45	)		(234	)
Other additions		69			296			1,219			1,584
Capitalised borrowing costs		—			—			30			30
Disposals and write-offs		(376	)		(685	)		(31	)		(1,092	)
Reclassifications		602			1,186			(1,826	)		(38	)
Transfer to assets held for sale		(462	)		(219	)		(14	)		(695	)
Cost at 31 December 2017		7,467			11,751			2,501			21,719
Depreciation at 1 January 2016		(2,914	)		(7,415	)		—			(10,329	)
Exchange adjustments		(377	)		(717	)		—			(1,094	)
Charge for the year		(338	)		(640	)		—			(978	)
Disposals and write-offs		205			1,270			—			1,475
Transfer to assets held for sale		165			92			—			257
Depreciation at 31 December 2016		(3,259	)		(7,410	)		—			(10,669	)
Exchange adjustments		50			110			—			160
Charge for the year		(299	)		(689	)		—			(988	)
Disposals and write-offs		158			539			—			697
Transfer to assets held for sale		314			190			—			504
Depreciation at 31 December 2017		(3,036	)		(7,260	)		—			(10,296	)
Impairment at 1 January 2016		(274	)		(373	)		(106	)		(753	)
Exchange adjustments		(45	)		(37	)		(11	)		(93	)
Disposals and write-offs		91			135			35			261
Impairment losses		(135	)		(117	)		(6	)		(258	)
Reversal of impairments		38			38			2			78
Transfer to assets held for sale		46			10			22			78
Impairment at 31 December 2016		(279	)		(344	)		(64	)		(687	)
Exchange adjustments		8			2			(2	)		8
Disposals and write-offs		210			104			28			342
Impairment losses		(194	)		(138	)		(17	)		(349	)
Reversal of impairments		7			9			1			17
Transfer to assets held for sale		87			8			11			106
Impairment at 31 December 2017		(161	)		(359	)		(43	)		(563	)
Total depreciation and impairment at 31 December 2016		(3,538	)		(7,754	)		(64	)		(11,356	)
Total depreciation and impairment at 31 December 2017		(3,197	)		(7,619	)		(43	)		(10,859	)
Net book value at 1 January 2016		4,117			2,987			2,564			9,668
Net book value at 31 December 2016		4,223			3,481			3,104			10,808
Net book value at 31 December 2017		4,270			4,132			2,458			10,860

XML

Goodwill (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Changes in Goodwill

	2017			2016
	£m			£m
Cost at 1 January		5,965			5,162
Exchange adjustments		(228	)		814
Additions through business combinations (Note 38)		—			7
Transfer to assets held for sale		(3	)		(18	)
Cost at 31 December		5,734			5,965
Net book value at 1 January		5,965			5,162
Net book value at 31 December		5,734			5,965

Summary of Goodwill Allocated to Segments

	2017			2016
	£m			£m
Cost at 1 January		5,965			5,162
Exchange adjustments		(228	)		814
Additions through business combinations (Note 38)		—			7
Transfer to assets held for sale		(3	)		(18	)
Cost at 31 December		5,734			5,965
Net book value at 1 January		5,965			5,162
Net book value at 31 December		5,734			5,965
Goodwill is allocated to the Group’s segments as follows:
	2017			2016
	£m			£m
Pharmaceuticals		3,172			3,288
Vaccines		1,302			1,353
Consumer Healthcare		1,260			1,324
Net book value at 31 December		5,734			5,965

Schedule of Discounted Cash Flow Models Used in Impairment Tests

Details relating to the discounted cash flow models used in the impairment tests of the Pharmaceuticals, Vaccines and Consumer Healthcare cash generating units are as follows:

Valuation basis	Fair value less costs of disposal
Key assumptions	Sales growth rates
	Profit margins
	Terminal growth rate
	Discount rate
	Taxation rate
Determination of assumptions	Growth rates are internal forecasts based on both internal and external market information.
	Margins reflect past experience, adjusted for expected changes.
	Terminal growth rates based on management’s estimate of future long-term average growth rates.
	Discount rates based on Group WACC, adjusted where appropriate.
	Taxation rates based on appropriate rates for each region.
Period of specific projected cash flows	Five years
Terminal growth rate and discount rate		Terminal growth rate		Discount rate
	Pharmaceuticals		1% p.a.		7%
	Vaccines		2% p.a.		7%
	Consumer Healthcare		2% p.a.		7%

XML

Other intangible assets (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Other Intangible Assets

	Computer			Licences,			Amortised			Indefinite life
	software			patents, etc.			brands			brands			Total
	£m			£m			£m			£m			£m
Cost at 1 January 2016		2,028			13,394			387			8,074			23,883
Exchange adjustments		137			1,139			20			1,320			2,616
Capitalised development costs		—			219			21			—			240
Capitalised borrowing costs		4			—			—			—			4
Additions through business combinations		—			102			—			—			102
Other additions		238			349			—			—			587
Disposals and asset write-offs		(389	)		(21	)		(1	)		(7	)		(418	)
Transfer to assets held for sale		(1	)		(39	)		—			(12	)		(52	)
Reclassifications		139			—			—			—			139
Cost at 31 December 2016		2,156			15,143			427			9,375			27,101
Exchange adjustments		(37	)		(215	)		(4	)		(272	)		(528	)
Capitalised development costs		—			251			—			—			251
Capitalised borrowing costs		2			3			—			—			5
Other additions		233			221			—			—			454
Disposals and asset write-offs		(217	)		(38	)		—			—			(255	)
Transfer to assets held for sale		(1	)		(90	)		—			(44	)		(135	)
Reclassifications		38			—			66			(66	)		38
Cost at 31 December 2017		2,174			15,275			489			8,993			26,931
Amortisation at 1 January 2016		(1,294	)		(4,030	)		(133	)		—			(5,457	)
Exchange adjustments		(92	)		(410	)		(5	)		—			(507	)
Charge for the year		(152	)		(553	)		(91	)		—			(796	)
Disposals and asset write-offs		353			—			5			—			358
Transfer to assets held for sale		1			10			—			—			11
Amortisation at 31 December 2016		(1,184	)		(4,983	)		(224	)		—			(6,391	)
Exchange adjustments		25			141			—			—			166
Charge for the year		(163	)		(761	)		(10	)		—			(934	)
Disposals and asset write-offs		210			25			—			—			235
Transfer to assets held for sale		1			25			—			—			26
Amortisation at 31 December 2017		(1,111	)		(5,553	)		(234	)		—			(6,898	)
Impairment at 1 January 2016		(39	)		(1,439	)		(154	)		(122	)		(1,754	)
Exchange adjustments		(3	)		(266	)		—			(3	)		(272	)
Impairment losses		(2	)		(15	)		—			(5	)		(22	)
Disposals and asset write-offs		35			40			11			—			86
Transfer to assets held for sale		—			28			—			—			28
Impairment at 31 December 2016		(9	)		(1,652	)		(143	)		(130	)		(1,934	)
Exchange adjustments		—			110			—			3			113
Impairment losses		(2	)		(546	)		—			(132	)		(680	)
Disposals and asset write-offs		2			5			—			—			7
Transfer to assets held for sale		—			19			—			4			23
Impairment at 31 December 2017		(9	)		(2,064	)		(143	)		(255	)		(2,471	)
Total amortisation and impairment at 31 December 2016		(1,193	)		(6,635	)		(367	)		(130	)		(8,325	)
Total amortisation and impairment at 31 December 2017		(1,120	)		(7,617	)		(377	)		(255	)		(9,369	)
Net book value at 1 January 2016		695			7,925			100			7,952			16,672
Net book value at 31 December 2016		963			8,508			60			9,245			18,776
Net book value at 31 December 2017		1,054			7,658			112			8,738			17,562

Schedule of Amortisation and Impairment Losses, Net of Reversals

Amortisation and impairment losses, net of reversals, have been charged in the income statement as follows:

	Amortisation				Net impairment losses
	2017		2016		2017		2016
	£m		£m		£m		£m
Cost of sales		578		582		400		7
Selling, general and administration		116		95		2		2
Research and development		240		119		278		13
		934		796		680		22

Summary of Book Values of Largest Individual Items

Licences, patents, etc. includes a large number of acquired licences, patents, know-how agreements and marketing rights, which are either marketed or in use, or still in development. Note 38, ‘Acquisitions and disposals’ gives details of additions through business combinations in the year. The book values of the largest individual items are as follows:

	2017		2016
	£m		£m
Meningitis portfolio		2,450		2,511
dolutegravir		1,389		1,487
Benlysta		965		1,019
Fluarix/FluLaval		321		380
HIV assets acquired from BMS		277		277
Selzentry		162		188
Okairos technology platform		202		173
Others		1,892		2,473
		7,658		8,508

Summary of Book Values of Major Brands

Indefinite life brands comprise a portfolio of Consumer Healthcare products primarily acquired with the acquisitions of Sterling Winthrop, Inc. in 1994, Block Drug Company, Inc. in 2001, CNS, Inc. in 2006 and the Novartis Consumer Healthcare business in 2015, together with a number of pharmaceutical brands from the acquisition of Stiefel Laboratories, Inc. in 2009. The book values of the major brands are as follows:

	2017		2016
	£m		£m
Voltaren		2,716		2,847
Otrivin		1,380		1,447
Fenistil		648		680
Theraflu		441		462
Panadol		386		354
Sensodyne		265		243
Lamisil		289		304
Breathe Right		236		199
Stiefel trade name		228		211
Excedrin		185		194
Physiogel		166		166
Polident		112		103
Others		1,686		2,035
		8,738		9,245

XML

Investments in associates and joint ventures (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Schedule of Investments in Associates and Joint Ventures

	Joint						2017			Joint						2016
	ventures			Associates			Total			ventures			Associates			Total
	£m			£m			£m			£m			£m			£m
At 1 January		19			244			263			20			187			207
Exchange adjustments		(2	)		(10	)		(12	)		4			41			45
Additions		—			15			15			3			8			11
Disposals		—			(92	)		(92	)		—			—			—
Distributions received		(1	)		(1	)		(2	)		(2	)		(1	)		(3	)
Other movements		—			(2	)		(2	)		(2	)		—			(2	)
(Loss)/profit after tax recognised in the consolidated income statement		(3	)		16			13			(4	)		9			5
At 31 December		13			170			183			19			244			263

Summary of Balance Sheet Information

Summarised balance sheet information, based on results information, in respect of Innoviva is set out below:

	At 31 December			At 31 December
	2017			2016
	£m			£m
Non-current assets		124			146
Current assets		148			160
Current liabilities		(26	)		(16	)
Non-current liabilities		(426	)		(575	)
Net liabilities		(180	)		(285	)
	2017			2016
	£m			£m
Interest in associated undertaking		(57	)		(84	)
Goodwill		86			84
Fair value and other adjustments		118			138
Carrying value at 31 December		147			138

XML

Other investments (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Schedule of Other Investments

	2017			2016
	£m			£m
At 1 January		985			1,255
Exchange adjustments		(64	)		211
Additions		80			96
Net fair value movements		11			130
Impairment losses		(30	)		(24	)
Disposals		(64	)		(683	)
At 31 December		918			985

Schedule of Carrying Value of Other Investments

The carrying value at 31 December of Other investments which have been impaired is as follows:

	2017			2016
	£m			£m
Original cost		475			515
Cumulative impairments recognised in the income statement		(283	)		(314	)
Subsequent fair value increases		210			282
Carrying value at 31 December		402			483

XML

Other non-current assets (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Other Non-Current Assets

	2017		2016
	£m		£m
Amounts receivable under insurance contracts		648		602
Pension schemes in surplus		538		313
Other receivables		227		284
		1,413		1,199

XML

Inventories (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Inventories

	2017		2016
	£m		£m
Raw materials and consumables		1,193		1,068
Work in progress		2,381		2,299
Finished goods		1,983		1,735
		5,557		5,102

XML

Trade and other receivables (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Trade Receivables and Bad and Doubtful Debts

	2017		2016
	£m		£m
Trade receivables, net of provision for bad and doubtful debts		4,672		4,615
Accrued income		21		64
Other prepayments		308		335
Interest receivable		10		11
Employee loans and advances		19		17
Other receivables		970		984
		6,000		6,026

	2017			2016
Bad and doubtful debt provision	£m			£m
At 1 January		207			167
Exchange adjustments		(4	)		23
Charge for the year		31			77
Subsequent recoveries of amounts provided for		(79	)		(59	)
Utilised		(15	)		(1	)
At 31 December		140			207

XML

Cash and cash equivalents (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Cash and Cash Equivalents

	2017		2016
	£m		£m
Cash at bank and in hand		826		1,462
Short-term deposits		3,007		3,435
		3,833		4,897

XML

Assets held for sale (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Assets Held for Sale

	2017		2016
	£m		£m
Property, plant and equipment		57		184
Goodwill		—		13
Other intangibles		49		12
Inventory		7		7
Other		—		(1	)
		113		215

XML

Trade and other payables (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Trade and Other Payables

	2017		2016
	£m		£m
Trade payables		3,528		3,596
Wages and salaries		1,228		1,236
Social security		166		120
Consumer Healthcare put option		8,606		—
ViiV Healthcare put option		1,304		1,319
Other payables		363		447
Deferred income		240		158
Customer return and rebate accruals		3,463		2,778
Other accruals		2,072		2,310
		20,970		11,964

Summary of Increase/(Decrease) in Financial Liability and Loss/(Gain) in Income Statement

The table below shows on an indicative basis the income statement and balance sheet sensitivity to reasonably possible changes in key assumptions.

	2017
Increase/(decrease) in financial liability and loss/(gain) in Income statement	£m
10% increase in sales forecasts or sales multiple applied		850
10% decrease in sales forecasts or sales multiple applied		(850	)
10 cent appreciation of US Dollar		88
10 cent depreciation of US Dollar		(76	)
10 cent appreciation of Euro		303
10 cent depreciation of Euro		(254	)

Pfizer’s put option over its shareholding in ViiV Healthcare was recognised during 2016 and is currently exercisable. The table below shows on an indicative basis the income statement and balance sheet sensitivity of the Pfizer put option to reasonably possible changes in key assumptions.

	2017
Increase/(decrease) in financial liability and loss/(gain) in Income statement	£m
10% increase in sales forecasts		150
10% decrease in sales forecasts		(149	)
10 cent appreciation of US Dollar		76
10 cent depreciation of US Dollar		(66	)
10 cent appreciation of Euro		44
10 cent depreciation of Euro		(37	)

XML

Other provisions (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Other Provisions

	Legal			Major			Employee
	and other			restructuring			related			Other
	disputes			programmes			provisions			provisions			Total
	£m			£m			£m			£m			£m
At 1 January 2017		344			554			306			296			1,500
Exchange adjustments		(29	)		(16	)		(8	)		(6	)		(59	)
Charge for the year		173			259			50			69			551
Reversed unused		(7	)		(43	)		(3	)		(36	)		(89	)
Unwinding of discount		2			4			—			10			16
Utilised		(288	)		(233	)		(41	)		(67	)		(629	)
Reclassifications and other movements		(9	)		(3	)		—			5			(7	)
Transfer to Pension obligations		—			(18	)		—			—			(18	)
At 31 December 2017		186			504			304			271			1,265
To be settled within one year		138			292			90			109			629
To be settled after one year		48			212			214			162			636
At 31 December 2017		186			504			304			271			1,265

XML

Other non-current liabilities (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Other Noncurrent Liabilities

	2017		2016
	£m		£m
Accruals and deferred income		104		66
Consumer Healthcare put option liability		—		7,420
Other payables		877		959
		981		8,445

XML

Net debt (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Schedule of Current Assets, Short and Long Term Borrowings

		2017			2016
	Listing exchange	£m			£m
Current assets:
Liquid investments			78			89
Cash and cash equivalents			3,833			4,897
			3,911			4,986
Short-term borrowings:
Commercial paper			(529	)		(1,094	)
Bank loans and overdrafts			(236	)		(332	)
Obligations under finance leases			(23	)		(23	)
1.50% US$ US Medium Term Note 2017	New York Stock Exchange		—			(1,612	)
5.625% € European Medium Term Note 2017	London Stock Exchange		—			(1,068	)
5.65% US$ US Medium Term Note 2018	New York Stock Exchange		(2,037	)		—
			(2,825	)		(4,129	)
Long-term borrowings:
5.65% US$ US Medium Term Note 2018	New York Stock Exchange		—			(2,216	)
0.625% € European Medium Term Note 2019	London Stock Exchange		(1,324	)		(1,276	)
0% € European Medium Term Note 2020	London Stock Exchange		(1,060	)		—
2.85% US$ US Medium Term Note 2022	New York Stock Exchange		(1,474	)		(1,603	)
2.8% US$ US Medium Term Note 2023	New York Stock Exchange		(919	)		(999	)
1.375% € European Medium Term Note 2024	London Stock Exchange		(876	)		(845	)
4.00% € European Medium Term Note 2025	London Stock Exchange		(659	)		(635	)
1% € European Medium Term Note 2026	London Stock Exchange		(617	)		—
3.375% £ European Medium Term Note 2027	London Stock Exchange		(593	)		(593	)
1.375% € European Medium Term Note 2029	London Stock Exchange		(439	)		—
5.25% £ European Medium Term Note 2033	London Stock Exchange		(986	)		(986	)
5.375% US$ US Medium Term Note 2034	London Stock Exchange		(368	)		(401	)
6.375% US$ US Medium Term Note 2038	New York Stock Exchange		(2,021	)		(2,199	)
6.375% £ European Medium Term Note 2039	London Stock Exchange		(695	)		(695	)
5.25% £ European Medium Term Note 2042	London Stock Exchange		(989	)		(988	)
4.2% US$ US Medium Term Note 2043	New York Stock Exchange		(363	)		(395	)
4.25% £ European Medium Term Note 2045	London Stock Exchange		(789	)		(789	)
Obligations under finance leases			(43	)		(41	)
Other long term borrowings			(49	)		—
			(14,264	)		(14,661	)
Net debt			(13,178	)		(13,804	)

Schedule of Finance Lease Obligations

Finance lease obligations

	2017			2016
	£m			£m
Rental payments due within one year		25			25
Rental payments due between one and two years		29			23
Rental payments due between two and three years		9			12
Rental payments due between three and four years		3			7
Rental payments due between four and five years		2			—
Rental payments due after five years		10			—
Total future rental payments		78			67
Future finance charges		(12	)		(3	)
Total finance lease obligations		66			64

XML

Share capital and share premium account (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Share Capital and Share Premium

	Ordinary Shares of 25p each				Share premium
	Number		£m		£m
Share capital authorised
At 31 December 2015		10,000,000,000		2,500
At 31 December 2016		10,000,000,000		2,500
At 31 December 2017		10,000,000,000		2,500
Share capital issued and fully paid
At 1 January 2015		5,355,297,232		1,339		2,759
Issued under employee share schemes		6,010,415		1		72
At 31 December 2015		5,361,307,647		1,340		2,831
Issued under employee share schemes		7,008,415		2		87
Ordinary shares acquired by ESOP Trusts		—		—		36
At 31 December 2016		5,368,316,062		1,342		2,954
Issued under employee share schemes		4,237,758		1		55
Ordinary shares acquired by ESOP Trusts		—		—		10
At 31 December 2017		5,372,553,820		1,343		3,019

Summary of Share Capital

	31 December 2017		31 December 2016
	000		000
Number of shares issuable under employee share schemes		38,647		71,382
Number of unissued shares not under option		4,588,799		4,560,302

XML

Movements in equity (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Cumulative Translation Exchange in Equity

	Net translation exchange included in:
						Non-			Total
	Retained			Fair value		controlling			translation
	earnings			reserve		interests			exchange
	£m			£m		£m			£m
At 1 January 2015		(137	)		4		(117	)		(250	)
Exchange movements on overseas net assets		(624	)		6		8			(610	)
At 31 December 2015		(761	)		10		(109	)		(860	)
Exchange movements on overseas net assets		633			13		603			1,249
At 31 December 2016		(128	)		23		494			389
Exchange movements on overseas net assets		462			—		(149	)		313
Reclassification of exchange on liquidation or disposal of overseas subsidiaries		109			—		—			109
At 31 December 2017		443			23		345			811

The analysis of other comprehensive income by equity category is as follows:

							Non-
	Retained			Other			controlling
	earnings			reserves			interests			Total
2017	£m			£m			£m			£m
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges		462			—			—			462
Reclassification of exchange on liquidation or disposal of overseas subsidiaries		109			—			—			109
Fair value movements on available-for-sale investments		—			(14	)		—			(14	)
Reclassification of fair value movements on available-for-sale investments		—			(42	)		—			(42	)
Deferred tax on fair value movements on available-for-sale investments		—			47			—			47
Deferred tax reversed on reclassification of available for sale investments		—			(18	)		—			(18	)
Fair value movements on cash flow hedges		—			(10	)		—			(10	)
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests		—			—			(149	)		(149	)
Remeasurement gains on defined benefit plans		549			—			—			549
Tax on remeasurement gains in defined benefit plans		(221	)		—			—			(221	)
Other comprehensive income/(expense) for the year		899			(37	)		(149	)		713
							Non-
	Retained			Other			controlling
	earnings			reserves			interests			Total
2016	£m			£m			£m			£m
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges		633			13			—			646
Fair value movements on available-for-sale investments		—			251			—			251
Reclassification of fair value movements on available-for-sale investments		—			(245	)		—			(245	)
Deferred tax reversed on reclassification of available-for-sale investments		—			51			—			51
Reclassification of cash flow hedges to income statement		—			1			—			1
Fair value movements on cash flow hedges		—			2			—			2
Deferred tax on fair value movements on cash flow hedges		—			2			—			2
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests		—			—			603			603
Remeasurement losses on defined benefit plans		(475	)		—			—			(475	)
Tax on remeasurement losses in defined benefit plans		126			—			—			126
Other comprehensive income for the year		284			75			603			962

							Non-
	Retained			Other			controlling
	earnings			reserves			interests		Total
2015	£m			£m			£m		£m
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges		(624	)		6			—		(618	)
Fair value movements on available-for-sale investments		—			416			—		416
Deferred tax on fair value movements on available-for-sale investments		—			(91	)		—		(91	)
Reclassification of fair value movements on available-for-sale investments		—			(346	)		—		(346	)
Deferred tax reversed on reclassification of available-for-sale investments		—			36			—		36
Reclassification of cash flow hedges to income statement		—			2			—		2
Fair value movements on cash flow hedges		—			2			—		2
Share of other comprehensive expense of associates and joint ventures		(77	)		—			—		(77	)
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests		—			—			8		8
Remeasurement gains on defined benefit plans		261			—			—		261
Tax on remeasurement gains in defined benefit plans		(80	)		—			—		(80	)
Other comprehensive (expense)/income for the year		(520	)		25			8		(487	)

Summary of Analysis of Other Reserves

The analysis of other reserves is as follows:

	ESOP Trust			Fair value			Cash flow			Other
	shares			reserve			hedge reserve			reserves		Total
	£m			£m			£m			£m		£m
At 1 January 2015		(151	)		274			(13	)		2,129		2,239
Transferred to income and expense in the year on disposals		—			(356	)		2			—		(354	)
Transferred to income and expense in the year on impairments		—			10			—			—		10
Net fair value movement in the year		—			367			2			—		369
Ordinary shares acquired by ESOP Trusts		(99	)		—			—			—		(99	)
Write-down of shares held by ESOP Trusts		175			—			—			—		175
At 31 December 2015		(75	)		295			(9	)		2,129		2,340
Transferred to income and expense in the year on disposals		(16	)		(268	)		—			—		(284	)
Transferred to income and expense in the year on impairments		—			23			—			—		23
Net fair value movement in the year		—			330			6			—		336
Ordinary shares acquired by ESOP Trusts		(576	)		—			—			—		(576	)
Write-down of shares held by ESOP Trusts		381			—			—			—		381
At 31 December 2016		(286	)		380			(3	)		2,129		2,220
Transferred to income and expense in the year on disposals		22			(42	)		—			—		(20	)
Transferred to income and expense in the year on impairments		—			—			—			—		—
Net fair value movement in the year		—			(9	)		(8	)		—		(17	)
Ordinary shares acquired by ESOP Trusts		(656	)		—			—			—		(656	)
Write-down of shares held by ESOP Trusts		520			—			—			—		520
At 31 December 2017		(400	)		329			(11	)		2,129		2,047

XML

Adjustments reconciling profit after tax to operating cash flows (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Cash Generated from Operations

	2017			2016			2015
	£m			£m			£m
Profit after tax		2,169			1,062			8,372
Tax on profits		1,356			877			2,154
Share of after tax profits of associates and joint ventures		(13	)		(5	)		(14	)
Finance expense net of finance income		669			664			653
Depreciation		988			978			892
Amortisation of intangible assets		934			796			738
Impairment and assets written off		1,061			226			822
Profit on sale of businesses		(157	)		(5	)		(9,308	)
Profit on sale of intangible assets		(46	)		(178	)		(349	)
Profit on sale of investments in associates		(94	)		—			(843	)
Profit on sale of equity investments		(37	)		(254	)		(342	)
Changes in working capital:
(Increase)/decrease in inventories		(461	)		70			(111	)
(Increase)/decrease in trade receivables		(287	)		(188	)		98
Increase in trade payables		11			96			40
Decrease/(increase) in other receivables		74			381			(593	)
Contingent consideration paid (see Note 39)		(594	)		(358	)		(121	)
Other non-cash increase in contingent consideration liabilities		961			2,281			1,986
Increase in other payables		1,741			1,989			276
(Decrease)/increase in pension and other provisions		(255	)		(621	)		100
Share-based incentive plans		333			319			368
Fair value adjustments		—			(3	)		—
Other		(95	)		(21	)		(187	)
		6,089			7,044			(3,741	)
Cash generated from operations		8,258			8,106			4,631

XML

Reconciliation of net cash flow to movement in net debt (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Net Debt

	2017			2016			2015
	£m			£m			£m
Net debt at beginning of year		(13,804	)		(10,727	)		(14,377	)
(Decrease)/increase in cash and bank overdrafts		(905	)		(1,164	)		1,503
(Decrease)/increase in liquid investments		(4	)		—			2
Net increase in long-term loans		(2,233	)		—			—
Net repayment of/(increase in) short-term loans		3,200			(148	)		2,412
Net repayment of obligations under finance leases		23			18			25
Exchange adjustments		585			(1,781	)		(268	)
Other non-cash movements		(40	)		(2	)		(24	)
Movement in net debt		626			(3,077	)		3,650
Net debt at end of year		(13,178	)		(13,804	)		(10,727	)

Summary of Analysis of Changes in Net Debt

	At 1 January									Profit			Reclass-									At 31 December
	2017			Exchange			Other			and loss			ifications			Disposals			Cash flow			2017
Analysis of changes in net debt	£m			£m			£m			£m			£m			£m			£m			£m
Liquid investments		89			(7	)		—			—			—			—			(4	)		78
Cash and cash equivalents		4,897			(106	)		—			—			—			(6	)		(952	)		3,833
Overdrafts		(292	)		6			—			—			—			—			53			(233	)
		4,605			(100	)		—			—			—			(6	)		(899	)		3,600
Debt due within one year:
Commercial paper		(1,094	)		37			—			—			—			—			528			(529	)
European and US Medium Term Notes		(2,680	)		121			—			—			(2,114	)		—			2,636			(2,037	)
Other		(63	)		2			(5	)		—			(19	)		—			59			(26	)
		(3,837	)		160			(5	)		—			(2,133	)		—			3,223			(2,592	)
Debt due after one year:
European and US Medium Term Notes		(14,620	)		530			4			(16	)		2,114			—			(2,233	)		(14,221	)
Other		(41	)		2			(23	)		—			19			—			—			(43	)
		(14,661	)		532			(19	)		(16	)		2,133			—			(2,233	)		(14,264	)
Net debt		(13,804	)		585			(24	)		(16	)		—			(6	)		87			(13,178	)
Analysis of changes in liabilities from financing activities
Debt due within one year		(3,837	)		160			(5	)		—			(2,133	)		—			3,223			(2,592	)
Debt due after one year		(14,661	)		532			(19	)		(16	)		2,133			—			(2,233	)		(14,264	)
Hedge of borrowings:
Derivative financial instruments		(38	)		—			37			5			—			—			(2	)		2
Other financing items		—			91			—			—			—			—			(91	)		—
Interest payable		(158	)		4			1			(731	)		(100	)		—			781			(203	)
Total liabilities from financing activities		(18,694	)		787			14			(742	)		(100	)		—			1,678			(17,057	)

XML

Acquisitions and disposals (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Profit on Disposal of Businesses

The profit on disposal was determined as follows:

	Total
	£m
Consideration including currency forwards and purchase adjustments		342
Net assets sold:
Goodwill		(16	)
Intangible assets		(21	)
Property, plant and equipment		(18	)
Inventory		(11	)
Cash and cash equivalents		(6	)
Other net assets		(5	)
		(77	)
Transaction costs		(8	)
Reclassification of exchange from other comprehensive income		(100	)
Profit on disposal		157

	Oncology			Other
	£m			£m
Cash consideration including currency forwards and purchase adjustments		10,060			309
Net assets sold:
Goodwill		(497	)		(14	)
Intangible assets		(516	)		(107	)
Property, plant and equipment		—			(25	)
Inventory		—			(51	)
Cash		—			(5	)
Other net assets		—			(6	)
		(1,013	)		(208	)
Loss on currency forwards booked in 2014		299			—
Disposal costs		(118	)		(21	)
Profit on disposal		9,228			80

Summary of Investment in Associates and Joint Ventures

	Total
	£m
Cash consideration		198
Net book value of shares		(92	)
Reclassification of exchange from other comprehensive income		(7	)
Transaction costs		(5	)
Profit on disposal		94

	£m
Cash consideration		571
Net book value of shares		(143	)
Reclassification of exchange from other comprehensive income		(30	)
Transaction fees		(7	)
Other items		(5	)
Profit on disposal		386

Summary of Cash Flows from Business Combinations

Cash flows

				Associates			Associates
	Business			and JV			and JV
	disposals			investments			disposals
	£m			£m			£m
Cash consideration		256			(15	)		198
Net deferred consideration received		39			—			—
Cash and cash equivalents divested		(6	)		—			—
Transaction costs paid		(7	)		—			(2	)
Cash inflow		282			(15	)		196

Cash flows

	Business			Business
	acquisitions			disposals
	£m			£m
Cash consideration (paid)/received after purchase adjustments		(24	)		72
Cash and cash equivalents acquired		41			—
Cash inflow		17			72

Cash flows	Business acquisitions £m			Business disposals £m			Associates and JV disposals £m			Total £m
Cash consideration (paid)/received after purchase adjustments		(3,585	)		10,369			571			7,355
Cash and cash equivalents acquired/(divested)		404			(5	)		—			399
Deferred cash proceeds		—			(38	)		—			(38	)
Contingent consideration paid		(338	)		—			—			(338	)
Transaction costs and other		(22	)		(80	)		(7	)		(109	)
Cash (outflow)/inflow		(3,541	)		10,246			564			7,269

Summary of Fair Values of the Assets Acquired in Business Combinations, Including Goodwill

The fair values of the assets acquired in business combinations, including goodwill, are set out in the table below.

	Novartis
	Consumer			Novartis
	Healthcare			Vaccines
	business			business			Other
	£m			£m			£m
Net assets acquired:
Intangible assets		6,003			2,680			124
Property, plant and equipment		249			434			1
Inventory		257			347			—
Trade and other receivables		400			162			2
Other assets including cash and cash equivalents		304			283			19
Trade and other payables		(402	)		(107	)		(3	)
Deferred tax liabilities		(1,154	)		(78	)		(26	)
Other liabilities		(165	)		(299	)		—
		5,492			3,422			117
Non-controlling interest		(2,150	)		(19	)		—
Goodwill		774			576			22
		4,116			3,979			139
Consideration settled by shares in GSK Consumer Healthcare Holdings		4,116			—			—
Cash consideration paid after purchase adjustments		—			3,461			124
Fair value of equity investment disposal		—			—			15
Contingent consideration		—			594			—
Deferred tax on contingent consideration		—			(52	)		—
Loss on settlement of pre-existing relationships		—			(24	)		—
Total consideration		4,116			3,979			139

XML

Contingent consideration liabilities (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Summary of Fair Value of Contingent Consideration

The consideration for certain acquisitions includes amounts contingent on future events such as development milestones or sales performance. The Group has provided for the fair value of this contingent consideration as follows:

	Shionogi- ViiV Healthcare £m			Novartis Vaccines £m			Other £m			Total £m
At 1 January 2015		1,684			—			40			1,724
Additions through business combinations		—			594			—			594
Remeasurement through income statement		1,874			111			1			1,986
Cash payments: operating cash flows		(121	)		—			—			(121	)
Cash payments: investing activities		(38	)		(300	)		—			(338	)
Other movements		10			—			—			10
At 31 December 2015		3,409			405			41			3,855
Additions through business combinations		154			—			40			194
Remeasurement through income statement		2,162			152			(33	)		2,281
Cash payments: operating cash flows		(351	)		(5	)		(2	)		(358	)
Cash payments: investing activities		(66	)		(7	)		—			(73	)
Other movements		(4	)		—			1			(3	)
At 31 December 2016		5,304			545			47			5,896
Remeasurement through income statement		909			53			(1	)		961
Cash payments: operating cash flows		(587	)		(7	)		—			(594	)
Cash payments: investing activities		(84	)		(7	)		—			(91	)
At 31 December 2017		5,542			584			46			6,172

Summary of Possible Changes in key Inputs to Valuation of Contingent Consideration Liabilities

The table below shows on an indicative basis the income statement and balance sheet sensitivity to reasonably possible changes in key inputs to the valuations of the contingent consideration liabilities.

Increase/(decrease) in financial liability and loss/(gain) in Income statement	Shionogi- ViiV Healthcare £m			Novartis Vaccines £m
10% increase in sales forecasts		535			56
10% decrease in sales forecasts		(535	)		(55	)
1% increase in discount rate		(228	)		(18	)
1% decrease in discount rate		245			20
5% increase in probability of milestone success					6
5% decrease in probability of milestone success					(6	)
10 cent appreciation of US Dollar		329			17
10 cent depreciation of US Dollar		(284	)		(15	)
10 cent appreciation of Euro		95			25
10 cent depreciation of Euro		(80	)		(21	)

XML

Non-controlling interests (Tables)

12 Months Ended

Dec. 31, 2017

ViiV healthcare [member]

Summarised Financial Information of ViiV Healthcare Group and GSK Consumer Healthcare Joint Venture

Summarised financial information in respect of the ViiV Healthcare group and GSK Consumer Healthcare Joint Venture is set out below:

ViiV Healthcare

	2017 £m		2016 £m			2015 £m
Turnover		4,269		3,527			2,330
Profit/(loss) after taxation		825		(1,249	)		(1,426	)
Other comprehensive income		20		36			7
Total comprehensive income/(expense)		845		(1,213	)		(1,419	)

	2017 £m			2016 £m
Non-current assets		2,736			3,064
Current assets		2,533			2,357
Total assets		5,269			5,421
Current liabilities		(2,409	)		(1,977	)
Non-current liabilities		(8,011	)		(7,983	)
Total liabilities		(10,420	)		(9,960	)
Net liabilities		(5,151	)		(4,539	)

	2017 £m			2016 £m			2015 £m
Net cash inflow from operating activities		2,132			1,750			1,097
Net cash outflow from investing activities		(207	)		(326	)		(63	)
Net cash outflow from financing activities		(1,820	)		(1,023	)		(814	)
Increase in cash and bank overdrafts in the year		105			401			220

Schedule of Amount Attributable to VIIV Healthcare Group Included in GSK's Consolidated Statement of Comprehensive Income, Consolidated Statement of Changes in Equity and Consolidated Balance Shee

The following amounts attributable to the ViiV Healthcare group are included in GSK’s Consolidated statement of comprehensive income, Consolidated statement of changes in equity and Consolidated balance sheet:

	2017 £m			2016 £m			2015 £m
Total comprehensive income/(expense) for the year attributable to non-controlling interests		187			(83	)		(143	)
Dividends paid to non-controlling interests		316			152			163
Non-controlling interests in the Consolidated balance sheet		(476	)		(353	)

Consumer health care joint venture [member]

Summarised Financial Information of ViiV Healthcare Group and GSK Consumer Healthcare Joint Venture

Consumer Healthcare Joint Venture

	2017 £m			2016 £m		2015 £m
Turnover		7,003			6,530		4,627
Profit/(loss) after taxation		1,211			660		(39	)
Other comprehensive income		(387	)		1,640		72
Total comprehensive income		824			2,300		33

	2017 £m			2016 £m
Non-current assets		12,771			13,315
Current assets		3,282			3,996
Total assets		16,053			17,311
Current liabilities		(2,675	)		(3,060	)
Non-current liabilities		(1,537	)		(2,062	)
Total liabilities		(4,212	)		(5,122	)
Net assets		11,841			12,189

	2017 £m			2016 £m			2015 £m
Net cash inflow from operating activities		883			1,496			277
Net cash inflow/(outflow) from investing activities		270			(537	)		(691	)
Net cash outflow from financing activities		(1,194	)		(980	)		(42	)
Decrease in cash and bank overdrafts in the year		(41	)		(21	)		(456	)

Schedule of Amount Attributable to VIIV Healthcare Group Included in GSK's Consolidated Statement of Comprehensive Income, Consolidated Statement of Changes in Equity and Consolidated Balance Shee

The following amounts attributable to the Consumer Healthcare Joint Venture are included in GSK’s Consolidated statement of comprehensive income, Consolidated statement of changes in equity and Consolidated balance sheet:

	2017		2016		2015
	£m		£m		£m
Total comprehensive income for the year attributable to non-controlling interests		296		730		14
Dividends paid to non-controlling interests		420		346		—
Non-controlling interests in the Consolidated balance sheet		3,631		3,755

XML

Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Schedule of Contractual Obligations and Commitments

	2017		2016
Contractual obligations and commitments	£m		£m
Contracted for but not provided in the financial statements:
Intangible assets		5,254		7,199
Property, plant and equipment		584		496
Investments		107		166
Purchase commitments		346		52
Pensions		738		874
Other commitments		38		143
Interest on loans		8,510		9,410
Finance lease charges		12		3
		15,589		18,343

Summary of Commitments Under Non-Cancellable Operating Leases

Commitments under non-cancellable operating leases are disclosed below. £117 million (2016 – £186 million) is provided against these commitments on the Group’s balance sheet.

	2017		2016
Commitments under non-cancellable operating leases	£m		£m
Rental payments due within one year		186		153
Rental payments due between one and two years		149		129
Rental payments due between two and three years		122		94
Rental payments due between three and four years		107		74
Rental payments due between four and five years		94		66
Rental payments due after five years		387		324
Total commitments under non-cancellable operating leases		1,045		840

XML

Financial instruments and related disclosures (Tables)

12 Months Ended

Dec. 31, 2017

Summary of External Credit Exposure

These banks are used for local investment purposes.

2017	AAA/Aaa £m		AA/Aa £m		A/A £m		BBB/Baa £m		BB+/Ba1 and below /unrated £m		Total £m
Bank balances and deposits		—		423		1,167		80		45		1,715
US Treasury and Treasury repo only money market funds		1,715		—		—		—		—		1,715
Liquidity funds		403		—		—		—		—		403
Government securities		—		77		—		1		—		78
3rd party financial derivatives		—		26		42		—		—		68
Total		2,118		526		1,209		81		45		3,979
2016	AAA/Aaa £m		AA/Aa £m		A/A £m		BBB/Baa £m		BB+/Ba1 and below /unrated £m		Total £m
Bank balances and deposits		—		542		1,560		388		93		2,583
US Treasury and Treasury repo only money market funds		2,248		—		—		—		—		2,248
Liquidity funds		66		—		—		—		—		66
Government securities		—		85		—		4		—		89
3rd party financial derivatives		—		70		86		—		—		156
Total		2,314		697		1,646		392		93		5,142

Summary of Financial Assets and Liabilities

	2017									2016
		Notes		Carrying value £m			Fair value £m				Carrying value £m			Fair value £m
Available-for-sale investments:
Liquid investments (Government bonds)			a		78			78				89			89
Other investments			a		918			918				985			985
Loans and receivables:
Cash and cash equivalents					3,833			3,833				4,897			4,897
Trade and other receivables and Other non-current assets in scope of IAS 39			b		5,495			5,495				5,499			5,499
Financial assets at fair value through profit or loss:
Trade and other receivables and Other non-current assets in scope of IAS 39			a,b		506			506				361			361
Derivatives designated as at fair value through profit or loss			a,d,e		5			5				23			23
Derivatives classified as held for trading under IAS 39			a,d,e		71			71				133			133
Total financial assets					10,906			10,906				11,987			11,987
Financial liabilities measured at amortised cost:
Borrowings excluding obligations under finance leases:
– bonds in a designated hedging relationship			d		(4,315	)		(4,405	)			(3,189	)		(3,335	)
– other bonds					(11,894	)		(14,743	)			(14,111	)		(16,996	)
– bank loans and overdrafts					(236	)		(236	)			(332	)		(332	)
– commercial paper					(529	)		(529	)			(1,094	)		(1,094	)
– other borrowings					(49	)		(49	)			—			—
Total borrowings excluding obligations under finance leases			f		(17,023	)		(19,962	)			(18,726	)		(21,757	)
Obligations under finance leases					(66	)		(66	)			(64	)		(64	)
Total borrowings					(17,089	)		(20,028	)			(18,790	)		(21,821	)
Trade and other payables, Other provisions and certain
Other non-current liabilities in scope of IAS 39			c		(20,325	)		(20,325	)			(18,713	)		(18,713	)
Financial liabilities at fair value through profit or loss:
Contingent consideration liabilities			a,c		(6,172	)		(6,172	)			(5,896	)		(5,896	)
Derivatives designated as at fair value through profit or loss			a,d,e		(26	)		(26	)			(92	)		(92	)
Derivatives classified as held for trading under IAS 39			a,d,e		(48	)		(48	)			(102	)		(102	)
Total financial liabilities					(43,660	)		(46,599	)			(43,593	)		(46,624	)
Net financial assets and financial liabilities					(32,754	)		(35,693	)			(31,606	)		(34,637	)

Summary of Fair Value of Financial Instruments

	Level 1		Level 2			Level 3			Total
At 31 December 2017	£m		£m			£m			£m
Financial assets at fair value
Available–for–sale financial assets:
Liquid investments		77		1			—			78
Other investments		535		—			383			918
Other non-current assets		—		—			38			38
Financial assets at fair value through profit or loss:
Other non-current assets		—		382			44			426
Trade and other receivables		—		—			42			42
Derivatives designated as at fair value through profit or loss		—		5			—			5
Derivatives classified as held for trading under IAS 39		—		62			9			71
		612		450			516			1,578
Financial liabilities at fair value
Financial liabilities at fair value through profit or loss:
Contingent consideration liabilities		—		—			(6,172	)		(6,172	)
Derivatives designated as at fair value through profit or loss		—		(26	)		—			(26	)
Derivatives classified as held for trading under IAS 39		—		(47	)		(1	)		(48	)
		—		(73	)		(6,173	)		(6,246	)
	Level 1		Level 2			Level 3			Total
At 31 December 2016	£m		£m			£m			£m
Financial assets at fair value
Available–for–sale financial assets:
Liquid investments		84		5			—			89
Other investments		580		—			405			985
Other non-current assets		—		—			6			6
Financial assets at fair value through profit or loss:
Other non-current assets		—		355			—			355
Derivatives designated as at fair value through profit or loss		—		23			—			23
Derivatives classified as held for trading under IAS 39		—		133			—			133
		664		516			411			1,591
Financial liabilities at fair value
Financial liabilities at fair value through profit or loss:
Contingent consideration liabilities		—		—			(5,896	)		(5,896	)
Derivatives designated as at fair value through profit or loss		—		(92	)		—			(92	)
Derivatives classified as held for trading under IAS 39		—		(101	)		(1	)		(102	)
		—		(193	)		(5,897	)		(6,090	)

Summary of Financial and Non Financial Assets

	2017										2016
	At fair value through profit or loss £m		Loans and receivables £m		Financial instruments £m		Non- financial instruments £m		Total £m		At fair value through profit or loss £m		Loans and receivables £m		Financial instruments £m		Non- financial instruments £m		Total £m
Trade and other receivables (Note 24)		42		5,148		5,190		810		6,000		—		5,135		5,135		891		6,026
Other non-current assets (Note 22)		464		347		811		602		1,413		361		364		725		474		1,199
		506		5,495		6,001		1,412		7,413		361		5,499		5,860		1,365		7,225

Summary of Ageing of Financial Assets Which are Past Due and for Which No Provision for Bad or Doubtful Debts Has Been Made

The following table shows the ageing of such financial assets which are past due and for which no provision for bad or doubtful debts has been made:

	2017 £m		2016 £m
Past due by 1–30 days		142		137
Past due by 31–90 days		70		178
Past due by 91–180 days		64		55
Past due by 181–365 days		27		53
Past due by more than 365 days		108		98
		411		521

Reconciliation of Financial Instruments Within Trade and Other Payables, Other Provisions, Other Non-current Liabilities and Contingent Consideration Liabilities

	2017															2016
	At fair value															At fair value
	through			Other			Financial			Non-financial						through			Other			Financial			Non-financial
	profit or loss			liabilities			instruments			instruments			Total			profit or loss			liabilities			instruments			instruments			Total
	£m			£m			£m			£m			£m			£m			£m			£m			£m			£m
Trade and other payables (Note 27)		—			(20,129	)		(20,129	)		(841	)		(20,970	)		—			(11,041	)		(11,041	)		(923	)		(11,964	)
Other provisions (Note 29)		—			(117	)		(117	)		(1,148	)		(1,265	)		—			(113	)		(113	)		(1,387	)		(1,500	)
Other non-current liabilities (Note 30)		—			(79	)		(79	)		(902	)		(981	)		—			(7,559	)		(7,559	)		(886	)		(8,445	)
Contingent consideration liabilities (Note 39)		(6,172	)		—			(6,172	)		—			(6,172	)		(5,896	)		—			(5,896	)		—			(5,896	)
		(6,172	)		(20,325	)		(26,497	)		(2,891	)		(29,388	)		(5,896	)		(18,713	)		(24,609	)		(3,196	)		(27,805	)

Summary of Fair Values of Derivatives Held

	2017 Fair value					2016 Fair value
	Assets £m		Liabilities £m			Assets £m		Liabilities £m
Net investment hedges – Foreign exchange contracts (principal amount – £6,333 million (2016 – £5,362 million))		5		(25	)		18		(92	)
Cash flow hedges – Foreign exchange contracts (principal amount – £38 million (2016 – £170 million))		—		(1	)		5		—
Derivatives designated as at fair value through profit or loss		5		(26	)		23		(92	)
Foreign exchange contracts (principal amount – £14,449 million (2016 – £14,943 million))		62		(47	)		133		(99	)
Embedded and other derivatives		9		(1	)		—		(3	)
Derivatives classified as held for trading under IAS 39		71		(48	)		133		(102	)
Total derivative instruments		76		(74	)		156		(194	)

Summary of Offsetting of Financial Assets and Liabilities

he following tables set out the financial assets and liabilities that are offset, or subject to enforceable master netting arrangements and other similar agreements but not offset, as at 31 December 2017 and 31 December 2016. The column ‘Net amount’ shows the impact on the Group’s balance sheet if all offset rights were exercised.

At 31 December 2017	Gross financial assets/ (liabilities) £m			Financial (liabilities)/ assets offset £m			Net financial assets/ (liabilities) £m			Related amounts not offset £m			Net amount £m
Financial assets
Trade and other receivables		5,191			(1	)		5,190			(31	)		5,159
Derivative financial instruments		76			—			76			(64	)		12
Financial liabilities
Trade and other payables		(20,130	)		1			(20,129	)		31			(20,098	)
Derivative financial instruments		(74	)		—			(74	)		64			(10	)
At 31 December 2016	Gross financial assets/ (liabilities) £m			Financial (liabilities)/ assets offset £m			Net financial assets/ (liabilities) £m			Related amounts not offset £m			Net balance £m
Financial assets
Trade and other receivables		5,136			(1	)		5,135			(29	)		5,106
Derivative financial instruments		156			—			156			(117	)		39
Financial liabilities
Trade and other payables		(11,042	)		1			(11,041	)		29			(11,012	)
Derivative financial instruments		(194	)		—			(194	)		117			(77	)

Summary of Debt Interest Rate Repricing

The following table sets out the exposure of the Group to interest rates on debt, including commercial paper. The maturity analysis of fixed rate debt is stated by contractual maturity and of floating rate debt by interest rate repricing dates. For the purpose of this table, debt is defined as all classes of borrowings other than obligations under finance leases.

	2017			2016
	Total debt £m			Total £m
Floating and fixed rate debt less than one year		(2,802	)		(4,106	)
Between one and two years		(1,340	)		(2,216	)
Between two and three years		(1,076	)		(1,277	)
Between three and four years		(16	)		—
Between four and five years		(1,475	)		—
Between five and ten years		(3,664	)		(4,082	)
Greater than ten years		(6,650	)		(7,045	)
Total		(17,023	)		(18,726	)
Original issuance profile:
Fixed rate interest		(16,209	)		(17,342	)
Floating rate interest		(765	)		(1,381	)
Total interest bearing		(16,974	)		(18,723	)
Non-interest bearing		(49	)		(3	)
		(17,023	)		(18,726	)

Summary of Anticipated Contractual Cash Flows Including Interest Payable for the Non-Derivative Financial Liabilities on Undiscounted Basis

							Obligations				Finance charge on				Trade payables and
				Interest on				under finance				obligations under				other liabilities not
	Debt			debt				leases				finance leases				in net debt			Total
At 31 December 2017	£m			£m				£m				£m				£m			£m
Due in less than one year		(2,802	)		(555	)			(23	)			(2	)			(21,521	)		(24,903	)
Between one and two years		(1,344	)		(497	)			(27	)			(2	)			(853	)		(2,723	)
Between two and three years		(1,078	)		(488	)			(8	)			(1	)			(813	)		(2,388	)
Between three and four years		(16	)		(488	)			(2	)			(1	)			(784	)		(1,291	)
Between four and five years		(1,483	)		(468	)			(1	)			(1	)			(752	)		(2,705	)
Between five and ten years		(3,694	)		(2,018	)			(5	)			(5	)			(3,609	)		(9,331	)
Greater than ten years		(6,720	)		(3,996	)			—				—				(1,471	)		(12,187	)
Gross contractual cash flows		(17,137	)		(8,510	)			(66	)			(12	)			(29,803	)		(55,528	)
												Finance charge on				Trade payables and
								Obligations				obligations				other
				Interest on				under finance				under finance				liabilities not
	Debt			debt				leases				leases				in net debt			Total
At 31 December 2016	£m			£m				£m				£m				£m			£m
Due in less than one year		(4,108	)		(705	)			(23	)			(2	)			(11,621	)		(16,459	)
Between one and two years		(2,218	)		(566	)			(22	)			(1	)			(8,784	)		(11,591	)
Between two and three years		(1,282	)		(503	)			(12	)			—				(961	)		(2,758	)
Between three and four years		—			(496	)			(7	)			—				(786	)		(1,289	)
Between four and five years		—			(496	)			—				—				(705	)		(1,201	)
Between five and ten years		(4,117	)		(2,122	)			—				—				(3,474	)		(9,713	)
Greater than ten years		(7,124	)		(4,522	)			—				—				(3,135	)		(14,781	)
Gross contractual cash flows		(18,849	)		(9,410	)			(64	)			(3	)			(29,466	)		(57,792	)

Summary of Anticipated Contractual Cash Flows for Derivative Instruments, Excluding Embedded Derivatives and Equity Options, Using Undiscounted Cash Flows

The amounts receivable and payable in less than one year have decreased compared with 31 December 2016 as a result of reduced hedging of the US commercial paper programme.

	2017					2016
	Receivables		Payables			Receivables		Payables
	£m		£m			£m		£m
Due in less than one year		20,319		(20,326	)		21,266		(21,303	)
Between one and two years		—		—			20		(20	)
Gross contractual cash flows		20,319		(20,326	)		21,286		(21,323	)

Currency risk [member]

Sensitivity Analysis for Each Type of Market Risk

	2017			2016
Income statement impact of non-functional currency foreign exchange exposures	Increase/(decrease) in income £m			Increase/(decrease) in income £m
10 cent appreciation of the US Dollar		76			77
10 cent appreciation of the Euro		(5	)		18
10 yen appreciation of the Yen		9			1
	2017			2016
Income statement impact of non-functional currency foreign exchange exposures	Increase/(decrease) in income £m			Increase/(decrease) in income £m
10 cent depreciation of the US Dollar		(66	)		(66	)
10 cent depreciation of the Euro		4			(16	)
10 yen depreciation of the Yen		(8	)		(1	)

The equity impact, shown below, for foreign exchange sensitivity relates to derivative and non-derivative financial instruments hedging the Group’s net investments in its European (Euro) foreign operations and cash flow hedges of its foreign exchange exposure arising on Euro denominated coupon payments relating to notes issued under the Group’s European Medium Term Note programme and a number of highly probable forecast transactions denominated in US Dollar.

	2017			2016
Equity impact of non-functional currency foreign exchange exposures	Increase/(decrease) in equity £m			Increase/(decrease) in equity £m
10 cent appreciation of the US Dollar		1			11
10 cent appreciation of the Euro		(1,028	)		(795	)
	2017			2016
Equity impact of non-functional currency foreign exchange exposures	Increase/(decrease) in equity £m			Increase/(decrease) in equity £m
10 cent depreciation of the US Dollar		(1	)		(10	)
10 cent depreciation of the Euro		861			670

The tables below present the Group’s sensitivity to a weakening and strengthening of Sterling against the relevant currency based on the composition of net debt as shown in Note 31 adjusted for the effects of foreign exchange derivatives that are not part of net debt but affect future foreign currency cash flows.

	2017			2016
Impact of foreign exchange movements on net debt	(Increase)/decrease in net debt £m			(Increase)/decrease in net debt £m
10 cent appreciation of the US Dollar		(637	)		(746	)
10 cent appreciation of the Euro		197			190
10 yen appreciation of the Yen		(4	)		(11	)
	2017			2016
Impact of foreign exchange movements on net debt	(Increase)/decrease in net debt £m			(Increase)/decrease in net debt £m
10 cent depreciation of the US Dollar		549			634
10 cent depreciation of the Euro		(165	)		(160	)
10 yen depreciation of the Yen		4			10

Interest rate risk [member]

Sensitivity Analysis for Each Type of Market Risk

The table below hypothetically shows the Group’s sensitivity to changes in interest rates in relation to Sterling, US Dollar and Euro floating rate financial assets and liabilities. If the interest rates applicable to floating rate financial assets and liabilities were to have increased by 1% (100 basis points), and assuming other variables had remained constant, it is estimated that the Group’s finance income for 2017 would have increased by approximately £5 million (2016 – £3 million increase). A 1% (100 basis points) movement in interest rates is not deemed to have a material effect on equity.

	2017			2016
Income statement impact of interest rate movements	Increase/(decrease) in income £m			Increase/(decrease) in income £m
1% (100 basis points) increase in Sterling interest rates		24			3
1% (100 basis points) increase in US Dollar interest rates		(24	)		(3	)
1% (100 basis points) increase in Euro interest rates		5			3

Level 3 [member]

Summary of Fair Value of Financial Instruments

Movements in the year for financial instruments measured using Level 3 valuation methods are presented below:

	2017			2016
	£m			£m
At 1 January		(5,486	)		(3,582	)
Net losses recognised in the income statement		(970	)		(2,283	)
Net gains recognised in other comprehensive income		22			29
Contingent consideration for businesses divested/acquired during the year		80			(194	)
Payment of contingent consideration liabilities		685			431
Additions		117			81
Disposals		(52	)		(15	)
Transfers from Level 3		(24	)		(11	)
Exchange		(29	)		58
At 31 December		(5,657	)		(5,486	)

XML

Employee share schemes (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Schedule of Number of Shares and ADS Issuable

	Shares			Weighted		ADS			Weighted
Number of shares and ADS issuable	Number (000)			fair value		Number (000)			fair value
At 1 January 2015		32,912					21,227
Awards granted		13,019		£	11.57		7,198		$	35.66
Awards exercised		(11,476	)				(8,878	)
Awards cancelled		(1,878	)				(2,027	)
At 31 December 2015		32,577					17,520
Awards granted		12,983		£	14.97		6,589		$	39.18
Awards exercised		(11,198	)				(6,214	)
Awards cancelled		(1,507	)				(812	)
At 31 December 2016		32,855					17,083
Awards granted		13,018		£	13.68		6,610		$	35.63
Awards exercised		(10,596	)				(5,674	)
Awards cancelled		(1,352	)				(627	)
At 31 December 2017		33,925					17,392

Summary of Valuation Model Used to Valuing Saving - Related Option to Arrive at the Share Based Payment Charge

The assumptions used in the model are as follows:

	2017 Grant			2016 Grant			2015 Grant
Risk-free interest rate		0.54	%		0.32	%		0.88	%
Dividend yield		5.9	%		4.9	%		6.5	%
Volatility		23	%		23	%		21	%
Expected life		3 years			3 years			3 years
Savings-related options grant price (including 20% discount)	£	10.86		£	12.95		£	10.14

Summary of Option Outstanding

	Share option					Share option					Savings-related
Options outstanding	schemes – shares					schemes –  ADS					share option schemes
				Weighted					Weighted					Weighted
	Number			exercise		Number			exercise		Number			exercise
	000			price		000			price		000			price
At 31 December 2017		3,600		£	11.86		3,277		$	39.62		6,852		£	10.77
Range of exercise prices on options outstanding at year end	£	11.47	–	£	12.21	$	33.42	–	$	48.66	£	10.13	–	£	12.95
Weighted average market price on exercise during year				£	16.07				$	41.50				£	14.28
Weighted average remaining contractual life					1.4 years					1.0 years					2.1 years

Summary of Shares Held for Share Award Schemes

Shares held for share award schemes	2017		2016
Number of shares (000)		66,558		42,571
	£m		£m
Nominal value		17		11
Carrying value		399		285
Market value		880		665
Shares held for share option schemes	2017		2016
Number of shares (000)		139		139
	£m		£m
Nominal value		—		—
Carrying value		1		1
Market value		2		2

XML

Principal Group companies (Tables)

12 Months Ended

Dec. 31, 2017

Text block1 [abstract]

Schedule of Principal Subsidiaries and Their Countries of Incorporation

The following represent the principal subsidiaries and their countries of incorporation of the Group at 31 December 2017. The equity share capital of these entities is wholly owned by the Group except where its percentage interest is shown otherwise. All companies are incorporated in their principal country of operation except where stated.

England	US
Glaxo Group Limited	Block Drug Company, Inc. (63.5%)
Glaxo Operations UK Limited	Corixa Corporation
GlaxoSmithKline Capital plc	GlaxoSmithKline Capital Inc.
GlaxoSmithKline Consumer Healthcare Holdings Limited (63.5%)	GlaxoSmithKline Consumer Healthcare, L.P. (55.9%)
GlaxoSmithKline Consumer Healthcare (UK) Trading Limited (63.5%)	GlaxoSmithKline Holdings (Americas) Inc.
GlaxoSmithKline Export Limited	GlaxoSmithKline LLC
GlaxoSmithKline Finance plc	Human Genome Sciences, Inc.
GlaxoSmithKline Holdings Limited *	GSK Consumer Health, Inc. (formerly Novartis Consumer Health, Inc.) (63.5%)
GlaxoSmithKline Research & Development Limited	S.R. One, Limited
GlaxoSmithKline Services Unlimited *	Stiefel Laboratories, Inc.
GlaxoSmithKline UK Limited	ViiV Healthcare Company (78.3%)
Setfirst Limited
SmithKline Beecham Limited
ViiV Healthcare Limited (78.3%)
ViiV Healthcare UK Limited (78.3%)
Europe	Others
GlaxoSmithKline Biologicals SA (Belgium)	GlaxoSmithKline Argentina S.A. (Argentina)
GlaxoSmithKline Pharmaceuticals SA (Belgium)	GlaxoSmithKline Australia Pty Ltd (Australia)
GlaxoSmithKline Biologicals S.A.S. (France)	GlaxoSmithKline Consumer Healthcare Australia Pty Ltd (Australia) (63.5%)
GlaxoSmithKline Sante Grand Public SAS (France) (63.5%)	GlaxoSmithKline Brasil Limitada (Brazil)
Laboratoire GlaxoSmithKline (France)	GlaxoSmithKline Consumer Healthcare Inc. (Canada) (63.5%)
ViiV Healthcare SAS (France) (78.3%)	GlaxoSmithKline Inc. (Canada)
GlaxoSmithKline Consumer Healthcare GmbH & Co. KG	ID Biomedical Corporation of Quebec (Canada)
(Germany) (63.5%)	GlaxoSmithKline Limited (China (Hong Kong))
GlaxoSmithKline GmbH & Co. KG (Germany)	Sino-American Tianjin Smith Kline & French Laboratories Ltd (China) (34.9%)
GSK Vaccines GmbH (Germany)	GlaxoSmithKline Consumer Healthcare Limited (India) (72.5%)
GlaxoSmithKline Consumer Healthcare S.p.A. (Italy) (63.5%)	GlaxoSmithKline Pharmaceuticals Limited (India) (75%)
GlaxoSmithKline S.p.A. (Italy)	GlaxoSmithKline Consumer Healthcare Japan K.K. (Japan) (63.5%)
GSK Vaccines S.r.l. (Italy)	GlaxoSmithKline K.K. (Japan)
GlaxoSmithKline B.V. (Netherlands)	ViiV Healthcare Kabushiki Kaisha (Japan) (78.3%)
GlaxoSmithKline Consumer Healthcare Sp.z.o.o. (Poland) (63.5%)	GlaxoSmithKline Pakistan Limited (Pakistan) (82.6%)
GlaxoSmithKline Pharmaceuticals S.A. (Poland)	Glaxo Wellcome Manufacturing Pte Ltd. (Singapore)
GSK Services Sp z o.o. (Poland)	GlaxoSmithKline Korea Limited (Republic of Korea)
GlaxoSmithKline Trading Services Limited (Republic of Ireland) (i)	GlaxoSmithKline llaclari Sanayi ve Ticaret A.S. (Turkey)
GlaxoSmithKline Healthcare AO (Russia) (63.5%)
GlaxoSmithKline S.A. (Spain)
Laboratorios ViiV Healthcare, S.L. (Spain) (78.3%)
Novartis Consumer Health S.A. (Switzerland) (63.5%)

(i) Exempt from the provisions of section 347 and 348 of the Companies Act 2014 (Ireland), in accordance with the exemptions noted in Section 357 of that Act. Further subsidiaries, as disclosed on pages 276 to 286, are exempt from these provisions as they are also consolidated in the group financial statements.

* Directly held wholly owned subsidiary of GlaxoSmithKline plc.

XML

Presentation of the Financial Statements - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£)
Presentation Of The Financial Statements [Abstract]
Date of end of reporting period	Dec. 31, 2017
Period covered by financial statements	These financial statements cover the financial year from 1 January to 31 December 2017, with comparative figures for the financial years from 1 January to 31 December 2016 and, where appropriate, from 1 January to 31 December 2015.
Interest on tax	£ 24
Accrued interest payable on tax	£ 52

XML

Accounting Principles and Policies - Additional Information (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of accounting principles and policies [line items]
Cost of sales	£ 0
Co-promotion revenue	16,000,000	£ 9,000,000	£ 14,000,000
Milestone income	0	£ 0	£ 0
Provisions related to legal and other disputes	£ 0
Amortised brands [member] | Top of range [member]
Disclosure of accounting principles and policies [line items]
Estimated useful lives	20 years
ERP software systems [member] | Top of range [member]
Disclosure of accounting principles and policies [line items]
Estimated useful lives	Ten years
ERP software systems [member] | Bottom of range [member]
Disclosure of accounting principles and policies [line items]
Estimated useful lives	Seven years
Computer software [member] | Top of range [member]
Disclosure of accounting principles and policies [line items]
Estimated useful lives	Five years
Computer software [member] | Bottom of range [member]
Disclosure of accounting principles and policies [line items]
Estimated useful lives	Three years
Licences and franchises [member] | Top of range [member]
Disclosure of accounting principles and policies [line items]
Estimated useful lives	20 years

XML

Accounting Principles and Policies - Summary of Expected Useful Lives of Property Plant and Equipment (Detail)	12 Months Ended
	Dec. 31, 2017
Freehold buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives of property plant and equipment	20 to 50 years
Leasehold land and buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives of property plant and equipment	Lease term or 20 to 50 years
Plant and machinery [member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives of property plant and equipment	10 to 20 years
Equipment and vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Useful lives of property plant and equipment	3 to 10 years

XML

Key Accounting Judgements and Estimates - Additional Information (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of changes in accounting estimates [line items]
Turnover	£ 30,186,000,000	£ 27,889,000,000	£ 23,923,000,000
Tax charge for the year	1,356,000,000	877,000,000	2,154,000,000
Tax payable, current	995,000,000	1,305,000,000
Tax recoverable, current	258,000,000	226,000,000
Deferred tax liability	1,396,000,000	1,934,000,000
Deferred tax assets	3,796,000,000	4,374,000,000
Tax payable, non-current	£ 411,000,000	0
Effective tax rate	1.00%
Changed total tax charge	£ 35,000,000
Uncertain tax position charge	1,175,000,000	1,892,000,000
Legal costs	166,000,000	162,000,000
Provision for legal and other disputes	186,000,000	344,000,000
Other intangible assets	17,562,000,000	18,776,000,000	16,672,000,000
Contingent consideration and put option liabilities	(2,134,000,000)	(3,991,000,000)
Contingent consideration related to acquisition	£ 6,172,000,000	5,896,000,000	3,855,000,000	£ 1,724,000,000
Percentage of decrease in discount rate	0.25%
Net pension deficit	£ 800,000,000
Increased annual pension cost	29,000,000
Shionogi ViiV healthcare joint venture [member] | Trade and other payable [member] | Written put options [member]
Disclosure of changes in accounting estimates [line items]
Put option recognised	1,304,000,000
Shionogi ViiV healthcare joint venture [member]
Disclosure of changes in accounting estimates [line items]
Contingent consideration related to acquisition	5,542,000,000	5,304,000,000	£ 3,409,000,000	£ 1,684,000,000
Business combinations [member]
Disclosure of changes in accounting estimates [line items]
Contingent consideration liabilities	6,172,000,000	5,896,000,000
Novartis [member]
Disclosure of changes in accounting estimates [line items]
Contingent consideration related to acquisition	£ 584,000,000	545,000,000
Percentage of voting right	36.50%
Novartis [member] | Other noncurrent liabilities [member]
Disclosure of changes in accounting estimates [line items]
Financial liability recognised	£ 8,606,000,000	7,420,000,000
Pfizer [member] | Shionogi ViiV healthcare joint venture [member] | Written put options [member]
Disclosure of changes in accounting estimates [line items]
Put option recognised during year		1,070,000,000
Pfizer [member] | Shionogi ViiV healthcare joint venture [member] | Trade and other payable [member] | Written put options [member]
Disclosure of changes in accounting estimates [line items]
Put option recognised		£ 1,319,000,000

XML

New Accounting Requirements - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£)
Description Of New Accounting Requirements [Line Items]
IFRS 15, description	IFRS 15 'Revenue from contracts with customers' was issued in May 2014 and has been implemented by the Group from 1 January 2018. The Standard provides a single, principles-based approach to the recognition of revenue from all contracts with customers. It focuses on the identification of performance obligations in a contract and requires revenue to be recognised when or as those performance obligations are satisfied.
IFRS 9, description	IFRS 9 'Financial instruments' was issued in its final form in July 2014 and has been implemented by the Group from 1 January 2018. The Standard replaces the majority of IAS 39 and covers the classification, measurement and de-recognition of financial assets and financial liabilities, introduces a new impairment model for financial assets based on expected losses rather than incurred losses and provides a new hedge accounting model.
IFRS 16, description	IFRS 16 'Leases' was issued in January 2016 and will be implemented by the Group from 1 January 2019. The Standard will replace IAS 17 'Leases' and will require lease liabilities and 'right of use' assets to be recognised on the balance sheet for almost all leases.
Effect of overlay approach reclassification [member]
Description Of New Accounting Requirements [Line Items]
Cumulative adjustment increase decrease to equity	£ 11
Increase (decrease) due to application of IFRS 15 [member]
Description Of New Accounting Requirements [Line Items]
Cumulative adjustment increase decrease to equity	£ 4

XML

Exchange Rates - Summary of Currencies Translations and Relevant Exchange Rates (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
USD [member]
Disclosure of foreign exchange rates [line items]
Average rates	1.30	1.36	1.53
Period end rates	1.35	1.24	1.47
Euro [member]
Disclosure of foreign exchange rates [line items]
Average rates	1.15	1.23	1.37
Period end rates	1.13	1.17	1.36
Yen [member]
Disclosure of foreign exchange rates [line items]
Average rates	145	149	185
Period end rates	152	144	177

XML

Segment Information - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£) Segments Wholesalers	Dec. 31, 2016 GBP (£)	Dec. 31, 2015 GBP (£)
Disclosure of operating segments [line items]
Number of reportable operating segments | Segments	4
Description of factors used to identify entity's reportable segments	Operating segments are reported based on the financial information provided to the Chief Executive Officer and the responsibilities of the Corporate Executive Team (CET). GSK reports results under four segments Pharmaceuticals; Pharmaceuticals R&D; Vaccines and Consumer Healthcare, and individual members of the CET are responsible for each segment.
Turnover	£ 30,186	£ 27,889	£ 23,923
Total impairment	1,069	289	587
Shionogi-ViiV Healthcare [member]
Disclosure of operating segments [line items]
Contingent consideration liability	5,542	5,304
Pfizer put option	1,304	1,319
Consumer Healthcare [member]
Disclosure of operating segments [line items]
Turnover	7,750	7,193	6,038
Put option liability	8,606	7,420
Other Reconciling Items between Segment Profit and Operating Profit [member]
Disclosure of operating segments [line items]
Total impairment	995	68	385
Other Reconciling Items between Segment Profit and Operating Profit [member] | Withdrawal of tanzeum [member]
Disclosure of operating segments [line items]
Total impairment	£ 229
US [member] | Pharmaceuticals and Vaccines [member]
Disclosure of operating segments [line items]
Number of wholesalers | Wholesalers	3
Wholesalers 1 [member] | US [member] | Pharmaceuticals and Vaccines [member]
Disclosure of operating segments [line items]
Turnover	£ 2,449	2,139	1,574
Wholesalers 2 [member] | US [member] | Pharmaceuticals and Vaccines [member]
Disclosure of operating segments [line items]
Turnover	3,043	2,691	2,471
Wholesalers 3 [member] | US [member] | Pharmaceuticals and Vaccines [member]
Disclosure of operating segments [line items]
Turnover	£ 2,356	£ 2,129	£ 1,602

XML

Segment Information - Turnover by Segment (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of operating segments [line items]
Turnover	£ 30,186	£ 27,889	£ 23,923
Operating Segments [member]
Disclosure of operating segments [line items]
Turnover	30,186	27,889	23,851
Corporate and Other Unallocated [member]
Disclosure of operating segments [line items]
Turnover			72
Pharmaceuticals [member]
Disclosure of operating segments [line items]
Turnover	17,276	16,104	14,157
Pharmaceuticals [member] | Operating Segments [member]
Disclosure of operating segments [line items]
Turnover	17,276	16,104	14,157
Vaccines [member]
Disclosure of operating segments [line items]
Turnover	5,160	4,592	3,656
Vaccines [member] | Operating Segments [member]
Disclosure of operating segments [line items]
Turnover	5,160	4,592	3,656
Consumer Healthcare [member]
Disclosure of operating segments [line items]
Turnover	7,750	7,193	6,038
Consumer Healthcare [member] | Operating Segments [member]
Disclosure of operating segments [line items]
Turnover	£ 7,750	£ 7,193	£ 6,038

XML

Segment Information - Turnover by Product & Service (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of products and services [line items]
Turnover	£ 30,186	£ 27,889	£ 23,923
Consumer Healthcare [member]
Disclosure of products and services [line items]
Turnover	7,750	7,193	6,038
Consumer Healthcare [member] | Wellness [member]
Disclosure of products and services [line items]
Turnover	4,001	3,726	2,970
Consumer Healthcare [member] | Oral Care [member]
Disclosure of products and services [line items]
Turnover	2,466	2,223	1,875
Consumer Healthcare [member] | Nutrition [member]
Disclosure of products and services [line items]
Turnover	680	674	684
Consumer Healthcare [member] | Skin Health [member]
Disclosure of products and services [line items]
Turnover	603	570	509
Pharmaceuticals [member]
Disclosure of products and services [line items]
Turnover	17,276	16,104	14,157
Pharmaceuticals [member] | Respiratory [member]
Disclosure of products and services [line items]
Turnover	6,991	6,510	5,741
Pharmaceuticals [member] | HIV [member]
Disclosure of products and services [line items]
Turnover	4,350	3,556	2,322
Pharmaceuticals [member] | Immuno inflammation [member]
Disclosure of products and services [line items]
Turnover	377	340	263
Pharmaceuticals [member] | Established Pharmaceuticals [Member]
Disclosure of products and services [line items]
Turnover	5,558	5,698	5,831
Vaccines [member]
Disclosure of products and services [line items]
Turnover	5,160	4,592	3,656
Vaccines [member] | Meningitis [member]
Disclosure of products and services [line items]
Turnover	890	662	326
Vaccines [member] | Influenza [member]
Disclosure of products and services [line items]
Turnover	488	414	268
Vaccines [member] | Shingles [member]
Disclosure of products and services [line items]
Turnover	22
Vaccines [member] | Established vaccines [member]
Disclosure of products and services [line items]
Turnover	£ 3,760	£ 3,516	£ 3,062

XML

Segment Information - Segment Profit and Operating Profit (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment profit
Operating profit	£ 4,087	£ 2,598	£ 10,322
Finance income	65	72	104
Finance costs	(734)	(736)	(757)
Profit on disposal of interest in associates	94		843
Share of after tax profits of associates and joint ventures	13	5	14
Profit before taxation	3,525	1,939	10,526
Taxation	(1,356)	(877)	(2,154)
Profit after taxation for the year	2,169	1,062	8,372
Depreciation and amortisation by segment
Total depreciation and amortisation	1,922	1,774	1,630
PP&E, intangible asset and goodwill impairment by segment
Total impairment	1,069	289	587
PP&E and intangible asset impairment reversals by segment
Total impairment reversals	(52)	(87)	(24)
Net operating assets	15,117	16,966
Net debt	(13,178)	(13,804)
Investments in associates and joint ventures	183	263	207
Derivative financial instruments	2	(38)
Current and deferred taxation	1,252	1,361
Assets held for sale	113	215
Net assets	3,489	4,963
Operating Segments [member]
Segment profit
Operating profit	8,944	8,033	5,923
Depreciation and amortisation by segment
Total depreciation and amortisation	1,187	1,092	934
PP&E, intangible asset and goodwill impairment by segment
Total impairment	71	197	184
PP&E and intangible asset impairment reversals by segment
Total impairment reversals	(16)	(52)	(22)
Net operating assets	14,249	17,194
Corporate and Other Unallocated [member]
Segment profit
Operating profit	(376)	(362)	(264)
Depreciation and amortisation by segment
Total depreciation and amortisation	144	94	145
PP&E, intangible asset and goodwill impairment by segment
Total impairment	3	24	18
PP&E and intangible asset impairment reversals by segment
Total impairment reversals		(26)	(2)
Net operating assets	868	(228)
Other Reconciling Items between Segment Profit and Operating Profit [member]
Segment profit
Operating profit	(4,481)	(5,073)	4,663
Depreciation and amortisation by segment
Total depreciation and amortisation	591	588	551
PP&E, intangible asset and goodwill impairment by segment
Total impairment	995	68	385
PP&E and intangible asset impairment reversals by segment
Total impairment reversals	(36)	(9)
Pharmaceuticals [member] | Operating Segments [member]
Segment profit
Operating profit	8,667	7,976	6,449
Depreciation and amortisation by segment
Total depreciation and amortisation	551	440	303
PP&E, intangible asset and goodwill impairment by segment
Total impairment	38	29	57
PP&E and intangible asset impairment reversals by segment
Total impairment reversals	(13)	(15)	(8)
Net operating assets	2,017	3,225
Pharmaceuticals Research and Development [member] | Operating Segments [member]
Segment profit
Operating profit	(2,740)	(2,488)	(2,168)
Depreciation and amortisation by segment
Total depreciation and amortisation	96	211	238
PP&E, intangible asset and goodwill impairment by segment
Total impairment	10	88	105
PP&E and intangible asset impairment reversals by segment
Total impairment reversals	(2)	(10)	(10)
Net operating assets	522	572
Pharmaceuticals Including Research and Development [member] | Operating Segments [member]
Segment profit
Operating profit	5,927	5,488	4,281
Depreciation and amortisation by segment
Total depreciation and amortisation	647	651	541
PP&E, intangible asset and goodwill impairment by segment
Total impairment	48	117	162
PP&E and intangible asset impairment reversals by segment
Total impairment reversals	(15)	(25)	(18)
Net operating assets	2,539	3,797
Vaccines [member] | Operating Segments [member]
Segment profit
Operating profit	1,644	1,429	958
Depreciation and amortisation by segment
Total depreciation and amortisation	405	315	253
PP&E, intangible asset and goodwill impairment by segment
Total impairment	13	34	17
PP&E and intangible asset impairment reversals by segment
Total impairment reversals		(19)
Net operating assets	9,707	9,676
Consumer Healthcare [member] | Operating Segments [member]
Segment profit
Operating profit	1,373	1,116	684
Depreciation and amortisation by segment
Total depreciation and amortisation	135	126	140
PP&E, intangible asset and goodwill impairment by segment
Total impairment	10	46	5
PP&E and intangible asset impairment reversals by segment
Total impairment reversals	(1)	(8)	£ (4)
Net operating assets	£ 2,003	£ 3,721

XML

Segment Information - Summary of Geographical Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of geographical areas [line items]
Turnover	£ 30,186	£ 27,889	£ 23,923
Non-current assets	34,566	36,096
UK [member]
Disclosure of geographical areas [line items]
Non-current assets	6,824	7,060
US [member]
Disclosure of geographical areas [line items]
Non-current assets	6,841	7,802
International [member]
Disclosure of geographical areas [line items]
Non-current assets	20,901	21,234
Customer [member]
Disclosure of geographical areas [line items]
Turnover	30,186	27,889	23,923
Customer [member] | UK [member]
Disclosure of geographical areas [line items]
Turnover	940	1,056	1,102
Customer [member] | US [member]
Disclosure of geographical areas [line items]
Turnover	11,263	10,197	8,222
Customer [member] | International [member]
Disclosure of geographical areas [line items]
Turnover	£ 17,983	£ 16,636	£ 14,599

XML

Other Operating Income/(Expense) - Information about Other Operating Income Expense (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of other operating income expense [abstract]
Impairment of equity investments	£ (30)	£ (47)	£ (263)
Disposal of equity investments	37	254	342
Disposal of businesses and assets	195	283	9,661
Fair value remeasurements on contingent consideration recognised in business combinations	(1,012)	(2,205)	(1,965)
Remeasurement of ViiV Healthcare put option liabilities and preferential dividends	13	(577)
Remeasurement of Consumer Healthcare put option liability	(1,186)	(1,133)	(83)
Fair value adjustments on derivative financial instruments	9	(3)	2
Other income/(expense)	9	23	21
Other operating income expense	£ (1,965)	£ (3,405)	£ 7,715

XML

Other Operating Income/(Expense) - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of other operating income expense [line items]
Disposal of businesses and assets	£ 195	£ 283	£ 9,661
Fair value remeasurements on contingent consideration	(1,012)	(2,205)	(1,965)
Other operating expenses	(1,965)	(3,405)	7,715
US tax reform [member]
Disclosure of other operating income expense [line items]
Other operating expenses	(666)
Vaccines business acquisition [member]
Disclosure of other operating income expense [line items]
Fair value remeasurements on contingent consideration	53
Ofatumumab [member]
Disclosure of other operating income expense [line items]
Milestone income included in disposal of businesses		£ 152
Disposal of the divestment			200
Oncology [member]
Disclosure of other operating income expense [line items]
Disposal of businesses and assets			£ 9,228
Anaesthesia [member]
Disclosure of other operating income expense [line items]
Disposal of businesses and assets	250
Shionogi ViiV healthcare joint venture [member]
Disclosure of other operating income expense [line items]
Fair value remeasurements on contingent consideration	£ 909

XML

Operating Profit - Summary of Information About Profit Loss (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Profit or loss [abstract]
Employee costs (Note 9)	£ 9,122,000,000	£ 8,212,000,000	£ 8,030,000,000
Advertising	1,351,000,000	1,265,000,000	1,059,000,000
Distribution costs	405,000,000	395,000,000	376,000,000
Depreciation of property, plant and equipment	988,000,000	978,000,000	892,000,000
Impairment of property, plant and equipment, net of reversals	327,000,000	180,000,000	346,000,000
Amortisation of intangible assets	934,000,000	796,000,000	738,000,000
Impairment of intangible assets, net of reversals	690,000,000	22,000,000	217,000,000
Net foreign exchange losses	215,000,000	53,000,000	47,000,000
Inventories:
Cost of inventories included in cost of sales	8,526,000,000	8,093,000,000	7,602,000,000
Write-down of inventories	701,000,000	533,000,000	488,000,000
Reversal of prior year write-down of inventories	(352,000,000)	(145,000,000)	(65,000,000)
Operating lease rentals:
Minimum lease payments	110,000,000	91,000,000	101,000,000
Contingent rents	4,000,000	4,000,000	8,000,000
Sub-lease payments	5,000,000	4,000,000	7,000,000
Fees payable to the company's auditor and its associates in relation to the Group	£ 29,200,000	£ 29,700,000	£ 33,100,000

XML

Operating Profit - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Operating Profit [line items]
Net foreign exchange losses	£ (215)	£ (53)	£ (47)
Major restructuring costs	1,056	970	1,891
Liquidation Or Disposal Of Overseas Subsidiary [member]
Disclosure of Operating Profit [line items]
Net foreign exchange losses	£ 109	£ 0	£ 0

XML

Operating Profit - Summary of Auditors Remuneration (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Auditor's remuneration [abstract]
Audit	£ 27.7	£ 26.6	£ 28.1
Taxation compliance	0.2	0.2	0.3
Taxation advice	0.1	1.8	3.2
Other assurance services	1.0	0.3	1.1
All other services	0.2	0.8	0.4
Auditors remuneration	29.2	29.7	33.1
Pension schemes [member]
Auditor's remuneration [abstract]
Audit	0.3	0.4	0.3
All other services	0.1	0.0	0.0
GLAXOSMITHKLINE PLC [member]
Auditor's remuneration [abstract]
Audit	7.0	5.8	7.5
Subsidiaries [member]
Auditor's remuneration [abstract]
Audit	16.2	16.4	16.3
Attestation under s.404 of Sarbanes-Oxley Act 2002 [member]
Auditor's remuneration [abstract]
Audit	£ 4.5	£ 4.4	£ 4.3

XML

Employee Costs - Summary of Employee Costs (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Short-term employee benefits expense [abstract]
Wages and salaries	£ 7,116	£ 6,391	£ 6,132
Social security costs	802	733	633
Pension and other post-employment costs, including augmentations (Note 28)	616	541	467
Cost of share-based incentive plans	347	338	349
Severance and other costs from integration and restructuring activities	241	209	449
Employee benefits expense	£ 9,122	£ 8,212	£ 8,030

XML

Employee Costs - Summary of Cost of Share-based Incentive Plans (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Expense from share based payment transactions with employees [line items]
Cost of share-based incentive plans	£ 347	£ 338	£ 349
Share Value Plan [member]
Expense from share based payment transactions with employees [line items]
Cost of share-based incentive plans	276	271	307
Performance Share Plan [member]
Expense from share based payment transactions with employees [line items]
Cost of share-based incentive plans	47	39	26
Share option plans [member]
Expense from share based payment transactions with employees [line items]
Cost of share-based incentive plans	4	4	4
Cash settled and other plans [member]
Expense from share based payment transactions with employees [line items]
Cost of share-based incentive plans	£ 20	£ 24	£ 12

XML

Employee Costs - Disclosure of Average Monthly Number of Persons Employed by the Group (Including Directors) (Detail) - Employee	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of employee costs and numbers [line items]
Average number of employees	99,349	99,827	101,192
Manufacturing [member]
Disclosure of employee costs and numbers [line items]
Average number of employees	38,632	38,611	37,025
Selling, general and administration [member]
Disclosure of employee costs and numbers [line items]
Average number of employees	49,141	49,961	52,121
Research and development [member]
Disclosure of employee costs and numbers [line items]
Average number of employees	11,576	11,255	12,046

XML

Employee Costs - Summary of Compensation of the Directors and Senior Management (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employees Benefit [abstract]
Wages and salaries	£ 26	£ 25	£ 23
Social security costs	4	4	2
Pension and other post-employment costs	3	2	3
Cost of share-based incentive plans	22	15	18
Key management personnel compensation	£ 55	£ 46	£ 46

XML

Major Restructuring Costs - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Major Restructuring Costs [Abstract]
Total restructuring costs	£ 1,056
Legacy support functions and Novartis integration provisions	43	£ 140	£ 44
Asset impairments	278	158	419
Other non-cash items	£ 247	£ 108	£ 51

XML

Major Restructuring Costs - Summary of Costs Charged to Operating Profit (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Major Restructuring Costs [Abstract]
Increase in provision for major restructuring programmes	£ 259	£ 163	£ 718
Amount of provision reversed unused	(43)	(140)	(44)
Impairment losses recognised	278	158	419
Other non-cash charges	247	108	51
Other cash costs	315	681	747
Cost charged to operating profit	£ 1,056	£ 970	£ 1,891

XML

Finance Income - Summary of Interest Income (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Analysis of income and expense [abstract]
cash and cash equivalents	£ 60	£ 67	£ 71
available-for-saleinvestments	2	1	1
derivatives at fair value through profit or loss			24
loans and receivables	1	2	3
Fair value adjustments on derivatives at fair value through profit or loss	2	2	5
Finance income	£ 65	£ 72	£ 104

XML

Finance Expense - Summary of Finance Cost (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest expense arising on:
financial liabilities at amortised cost	£ (698)	£ (671)	£ (655)
derivatives at fair value through profit or loss	(22)	(30)	(64)
Fair value movements on other derivatives at fair value through profit or loss	(4)	(3)	(6)
Reclassification of cash flow hedge from other comprehensive income		(1)	(2)
Unwinding of discounts on provisions	(16)	(16)	(16)
Other finance expense	6	(15)	(14)
Finance Costs	£ (734)	£ (736)	£ (757)

XML

Finance Expense - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£)
Disclosure Of Finance Expense [abstract]
Description of financial instrument	All derivatives accounted for at fair value through profit or loss, other than designated and effective hedging instruments (see Note 42, 'Financial instruments and related disclosures'), are classified as held-for-trading financial instruments under IAS 39. Interest expense arising on derivatives at fair value through profit or loss relates to swap interest expense.
Interest relating to income taxes	£ 24

XML

Associates and Joint Ventures - Summary of After Tax Profits and Losses of Associates and Joint Ventures (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of financial information of associates and joint ventures [line items]
Share of after tax profits and losses of associates and joint ventures	£ 13	£ 5	£ 14
Joint ventures [member]
Disclosure of financial information of associates and joint ventures [line items]
Share of after tax profits and losses of associates and joint ventures	(3)	(4)	(2)
Associates [member]
Disclosure of financial information of associates and joint ventures [line items]
Share of after tax profits and losses of associates and joint ventures	£ 16	£ 9	£ 16

XML

Associates and joint ventures - Additional Information (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of joint ventures and associates [line items]
Profit after taxation for the year	£ 13,000,000	£ 5,000,000	£ 14,000,000
Other comprehensive income	713,000,000	962,000,000	(487,000,000)
Sales to associates and joint ventures	41,000,000	£ 43,000,000	£ 41,000,000
Innoviva Inc [member]
Disclosure of joint ventures and associates [line items]
Profit after taxation for the year	18,000,000
Other comprehensive income	£ 0

XML

Associates and Joint Ventures - Summary of Group Held for Significant Associate (Detail) - GBP (£) £ in Millions	4 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of financial information of associates and joint ventures [line items]
Turnover		£ 30,186	£ 27,889	£ 23,923
Profit after taxation		2,169	1,062	8,372
Other comprehensive income		713	962	(487)
Total comprehensive income		2,882	2,024	£ 7,885
Innoviva Inc [member]
Disclosure of financial information of associates and joint ventures [line items]
Turnover	£ 20	165	98
Profit after taxation	4	103	44
Other comprehensive income	0	0	0
Total comprehensive income	£ 4	£ 103	£ 44

XML

Associates and Joint Ventures - Summary of Aggregated Financial Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of financial information of associates and joint ventures [line items]
Share of turnover	£ 30,186	£ 27,889	£ 23,923
Share of after tax (losses)/profits	2,169	1,062	8,372
Share of other comprehensive income	713	962	(487)
Share of total comprehensive (expense)/income	2,882	2,024	7,885
Other associates [member]
Disclosure of financial information of associates and joint ventures [line items]
Share of turnover	252	133	188
Share of after tax (losses)/profits	(5)	(1)	12
Share of other comprehensive income			25
Share of total comprehensive (expense)/income	£ (5)	£ (1)	£ 37

XML

Taxation - Summary of Taxation Charge Based on Profits (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current tax expense (income) and adjustments for current tax of prior periods [abstract]
Credit in respect of prior periods	£ (508)	£ (149)	£ (508)
Total current taxation	1,619	1,418	2,572
Total deferred taxation	(263)	(541)	(418)
Total tax	1,356	877	2,154
UK [member]
Current tax expense (income) and adjustments for current tax of prior periods [abstract]
Current tax expense (income)	199	241	156
International [member]
Current tax expense (income) and adjustments for current tax of prior periods [abstract]
Current tax expense (income)	£ 1,928	£ 1,326	£ 2,924

XML

Taxation - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income tax expense benefits [line items]
Average effective tax rate	38.50%	45.20%	20.50%
Other permanent differences	£ 196	£ 97	£ 58
Deferred tax charge related to equity	(222)	147	£ (177)
Provisions For Uncertain Tax Position	1,175	1,892
Provision for deferred tax liabilities	1,396	1,934
One-off repatriation tax charge	348
Unremitted profits for which deferred tax not provided	0	1,700
Unremitted profits	17,000	18,000
Deferred tax expense (income) recognised in profit or loss	247
Research and development incentives recognised in operating profit	16
Deferred tax assets recognized on trading losses	261	173
Deferred tax assets recognized on capital losses	54
Foreign tax credits for which deferred tax has not been recogized	721
Swiss tax reform [Member]
Income tax expense benefits [line items]
Deferred tax expense (income) recognised in profit or loss	483
Origination and reversal of temporary differences [Member]
Income tax expense benefits [line items]
Deferred tax expense (income) recognised in profit or loss	569
US tax reform [member]
Income tax expense benefits [line items]
Deferred tax expense (income) recognised in profit or loss	805
Overseas [Member]
Income tax expense benefits [line items]
Provision for deferred tax liabilities	209	£ 205
UK [member]
Income tax expense benefits [line items]
Payments of corporation tax	212
US and Belgium [member]
Income tax expense benefits [line items]
Other permanent differences	34
Deferred tax charge related to equity	(27)
Deferred tax charge related to statement of comprehensive income	£ (25)

XML

Taxation - Summary of Reconciliation of Tax Charge Calculated at the UK Statutory Rate on the Group Profit Before Tax with the Actual Tax Charge (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure - Taxation - Summary of Reconciliation of Tax Charge Calculated at the UK Statutory Rate on the Group Profit Before Tax with the Actual Tax Charge [Abstract]
Profit before tax	£ 3,525	£ 1,939	£ 10,526
UK statutory rate of taxation	679	388	2,131
Differences in overseas taxation rates	635	593	1,035
Benefit of intellectual property incentives	(458)	(321)	(286)
R&D credits	(75)	(93)	(38)
Remeasurement of non-taxable put option liabilities	227	340	17
Losses not recognised/(previously unrecognised losses)	28	(15)	31
Permanent differences on disposals and acquisitions	4	(21)	(248)
Other permanent differences	196	97	58
Reassessment of prior year estimates in respect of current and deferred taxes	(475)	(116)	(578)
US and Swiss tax reform	595
Tax on unremitted earnings		25	32
Tax charge/tax rate	£ 1,356	£ 877	£ 2,154
UK statutory rate of taxation	19.25%	20.00%	20.25%
Differences in overseas taxation rates	18.00%	30.60%	9.80%
Benefit of intellectual property incentives	(13.00%)	(16.50%)	(2.70%)
R&D credits	(2.10%)	(4.80%)	(0.40%)
Remeasurement of non-taxable put option liabilities	6.40%	17.50%	0.20%
Losses not recognised/(previously unrecognised losses)	0.80%	(0.80%)	0.30%
Permanent differences on disposals and acquisitions	0.10%	(1.10%)	(2.40%)
Other permanent differences	5.60%	5.00%	0.60%
Reassessment of prior year estimates in respect of current and deferred taxes	(13.50%)	(6.00%)	(5.50%)
US and Swiss tax reform	16.90%
Tax on unremitted earnings		1.30%	0.30%
Tax charge/tax rate	38.50%	45.20%	20.50%

XML

Taxation - Summary of Tax on Items Charged to Equity and Statement of Comprehensive Income (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred taxation
Share-based payments	£ (4)		£ (12)
Defined benefit plans	(247)	£ 94	(110)
Exchange movements	0	0	0
Fair value movements on cash flow hedges		2
Fair value movements on available-for-saleinvestments	29	51	(55)
Total equity and comprehensive income	(222)	147	(177)
Total (charge)/credit to equity and statement of comprehensive income	(196)	186	(125)
Share-based payments		7	22
Defined benefit plans	26	32	30
Total equity and comprehensive income	£ 26	£ 39	£ 52

XML

Taxation - Impact of Tax Reform on Profits Attributable to Shareholders (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income tax expense benefits [line items]
Other operating expenses	£ (1,965)	£ (3,405)	£ 7,715
Current tax	(1,619)	(1,418)	(2,572)
Deferred tax	263	541	418
Profit after taxation for the year	2,169	1,062	8,372
Profit attributable to non-controlling interests	637	150	(50)
Profit attributable to shareholders	1,532	£ 912	£ 8,422
Swiss tax reform [Member]
Income tax expense benefits [line items]
Deferred tax	483
Profit after taxation for the year	483
Profit attributable to non-controlling interests	176
Profit attributable to shareholders	307
US tax reform [member]
Income tax expense benefits [line items]
Other operating expenses	(666)
Current tax	(273)
Deferred tax	(805)
Profit after taxation for the year	(1,744)
Profit attributable to non-controlling interests	(114)
Profit attributable to shareholders	£ (1,630)

XML

Taxation - Impact on Tax Charge Arising From US Tax Reform (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of tax reform [line items]
Current tax	£ 1,619	£ 1,418	£ 2,572
Deferred tax	(263)	(541)	(418)
Tax charge/tax rate	1,356	£ 877	£ 2,154
US tax reform [member]
Disclosure of tax reform [line items]
Current tax	273
Deferred tax	805
US [member] | Revaluation of assets and liabilities [Member]
Disclosure of tax reform [line items]
Current tax	75
Deferred tax	(805)
Tax charge/tax rate	(730)
US [member] | Repatriation Taxes [Member]
Disclosure of tax reform [line items]
Current tax	(348)
Tax charge/tax rate	(348)
US [member] | US tax reform [member]
Disclosure of tax reform [line items]
Current tax	(273)
Deferred tax	(805)
Tax charge/tax rate	£ (1,078)

XML

Taxation - Summary of Movement in Deferred Tax Assets and Liabilities (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£)
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	£ 2,440
Exchange adjustments	(65)
Credit to income statement associated with Swiss tax reform	247
(Charge)/credit to statement of comprehensive income and equity	(222)
At 31 December 2017	2,400
Accelerate Capital Allowances [Member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	(377)
Exchange adjustments	(7)
At 31 December 2017	(317)
Share Option and Award Schemes [member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	110
Exchange adjustments	(4)
(Charge)/credit to statement of comprehensive income and equity	(4)
At 31 December 2017	74
Contingent Consideration [member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	1,138
At 31 December 2017	868
Intangible assets [member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	(2,324)
Exchange adjustments	75
At 31 December 2017	(1,320)
Tax losses [member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	227
Exchange adjustments	(5)
At 31 December 2017	261
Other temporary differences [member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	1,350
Exchange adjustments	(18)
(Charge)/credit to statement of comprehensive income and equity	29
At 31 December 2017	1,057
Origination and reversal of temporary differences [Member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	569
Origination and reversal of temporary differences [Member] | Accelerate Capital Allowances [Member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	62
Origination and reversal of temporary differences [Member] | Share Option and Award Schemes [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(1)
Origination and reversal of temporary differences [Member] | Contingent Consideration [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(52)
Origination and reversal of temporary differences [Member] | Intangible assets [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	330
Origination and reversal of temporary differences [Member] | Tax losses [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	59
Origination and reversal of temporary differences [Member] | Other temporary differences [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(88)
US tax reform [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(805)
US tax reform [member] | Accelerate Capital Allowances [Member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	5
US tax reform [member] | Share Option and Award Schemes [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(27)
US tax reform [member] | Contingent Consideration [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(218)
US tax reform [member] | Intangible assets [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	116
US tax reform [member] | Tax losses [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(20)
US tax reform [member] | Other temporary differences [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(216)
Swiss tax reform [Member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	483
Swiss tax reform [Member] | Intangible assets [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	483
Pensions and other post-employment benefits [member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	1,262
Exchange adjustments	(48)
(Charge)/credit to statement of comprehensive income and equity	(247)
At 31 December 2017	760
Pensions and other post-employment benefits [member] | Origination and reversal of temporary differences [Member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	3
Pensions and other post-employment benefits [member] | US tax reform [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	(210)
Intra Group Profit [member]
Changes in deferred tax liability (asset) [abstract]
At 1 January 2017	1,054
Exchange adjustments	(58)
At 31 December 2017	1,017
Intra Group Profit [member] | Origination and reversal of temporary differences [Member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	256
Intra Group Profit [member] | US tax reform [member]
Changes in deferred tax liability (asset) [abstract]
Credit to income statement associated with Swiss tax reform	£ (235)

XML

Taxation - Summary of Net Deferred Tax Asset (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Major components of tax expense (income) [abstract]
Deferred tax assets	£ 3,796	£ 4,374
Deferred tax liabilities	(1,396)	(1,934)
Total	£ 2,400	£ 2,440

XML

Taxation - Summary of Temporary Difference Unused Tax Losses and Unused Tax Credits (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Tax losses	£ 1,760	£ 1,723
Unrecognised deferred tax asset	300	401
Capital losses	372	396
Within 10 years [Member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Tax losses	802	786
Unrecognised deferred tax asset	187	255
Greater Than Ten Years [Member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Tax losses	872	842
Unrecognised deferred tax asset	99	131
Available Indefinitely [Member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Tax losses	86	95
Unrecognised deferred tax asset	14	15
Tax losses [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Tax losses	£ 1,924	£ 2,320

XML

Earnings per share - Summary of Basic and Diluted Earnings Per Share (Detail) - £ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings per share [abstract]
Basic earnings per share	£ 0.314	£ 0.188	£ 1.743
Diluted earnings per share	£ 0.310	£ 0.186	£ 1.723

XML

Earnings per share - Schedule of Numbers of Shares Earnings Per Share (Detail) - shares shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted average number of shares in issue
Basic	4,886	4,860	4,831
Dilution for share options and awards	55	49	57
Diluted	4,941	4,909	4,888

XML

Dividends - Summary of Interim Financial Reporting (Detail) - GBP (£) £ / shares in Units, £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of dividends [line items]
Dividend per share (pence)	£ 0.80	£ 0.80	£ 0.80
Total dividend	£ 3,911	£ 3,897	£ 3,872
First interim [member]
Disclosure of dividends [line items]
Paid	Jul. 13, 2017	Jul. 14, 2016	Jul. 09, 2015
Dividend per share (pence)	£ 0.19	£ 0.19	£ 0.19
Total dividend	£ 928	£ 923	£ 920
Second interim [member]
Disclosure of dividends [line items]
Paid	Oct. 12, 2017	Oct. 13, 2016	Oct. 01, 2015
Dividend per share (pence)	£ 0.19	£ 0.19	£ 0.19
Total dividend	£ 929	£ 925	£ 919
Third interim [member]
Disclosure of dividends [line items]
Paid	Jan. 11, 2018	Jan. 12, 2017	Jan. 14, 2016
Dividend per share (pence)	£ 0.19	£ 0.19	£ 0.19
Total dividend	£ 929	£ 925	£ 919
Fourth interim [member]
Disclosure of dividends [line items]
Paid	Apr. 12, 2018	Apr. 13, 2017	Apr. 14, 2016
Dividend per share (pence)	£ 0.23	£ 0.23	£ 0.23
Total dividend	£ 1,125	£ 1,124	£ 1,114
Special dividend [member]
Disclosure of dividends [line items]
Paid			Apr. 14, 2016
Dividend per share (pence)			£ 0.20
Total dividend			£ 969

XML

Dividends - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017
Disclosure of Dividends [abstract]
Description of compliance with IFRSs applied For interim financial report	Under IFRS interim dividends are only recognised in the financial statements when paid and not when declared. GSK normally pays a dividend two quarters after the quarter to which it relates and one quarter after it is declared. The 2017 financial statements recognise those dividends paid in 2017, namely the third and fourth interim dividends for 2016, and the first and second interim dividends for 2017.

XML

Dividends - Summary of Dividends to Shareholders (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Dividends [abstract]
Dividends to shareholders	£ 3,906	£ 4,850	£ 3,874

XML

Property, Plant and Equipment - Summary of Property, Plant and Equipment (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	£ 10,808	£ 9,668
Charge for the year	988	978	£ 892
Impairment losses	327	180	346
Reversal of impairments	33	171
Property, plant and equipment at end of period	10,860	10,808	9,668
Cost [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	22,164	20,750
Exchange adjustments	(234)	2,327
Other additions	1,584	1,544
Capitalised borrowing costs	30	30
Disposals and write-offs	(1,092)	(1,824)
Reclassifications	(38)	(139)
Transfer to assets held for sale	(695)	(524)
Property, plant and equipment at end of period	21,719	22,164	20,750
Depreciation [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(10,669)	(10,329)
Exchange adjustments	160	(1,094)
Charge for the year	(988)	(978)
Disposals and write-offs	697	1,475
Transfer to assets held for sale	504	257
Property, plant and equipment at end of period	(10,296)	(10,669)	(10,329)
Impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(687)	(753)
Exchange adjustments	8	(93)
Disposals and write-offs	342	261
Impairment losses	(349)	(258)
Reversal of impairments	17	78
Transfer to assets held for sale	106	78
Property, plant and equipment at end of period	(563)	(687)	(753)
Depreciation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(11,356)
Property, plant and equipment at end of period	(10,859)	(11,356)
Land and buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	4,223	4,117
Property, plant and equipment at end of period	4,270	4,223	4,117
Land and buildings [member] | Cost [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	7,761	7,305
Exchange adjustments	(127)	956
Other additions	69	117
Disposals and write-offs	(376)	(349)
Reclassifications	602	110
Transfer to assets held for sale	(462)	(378)
Property, plant and equipment at end of period	7,467	7,761	7,305
Land and buildings [member] | Depreciation [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(3,259)	(2,914)
Exchange adjustments	50	(377)
Charge for the year	(299)	(338)
Disposals and write-offs	158	205
Transfer to assets held for sale	314	165
Property, plant and equipment at end of period	(3,036)	(3,259)	(2,914)
Land and buildings [member] | Impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(279)	(274)
Exchange adjustments	8	(45)
Disposals and write-offs	210	91
Impairment losses	(194)	(135)
Reversal of impairments	7	38
Transfer to assets held for sale	87	46
Property, plant and equipment at end of period	(161)	(279)	(274)
Land and buildings [member] | Depreciation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(3,538)
Property, plant and equipment at end of period	(3,197)	(3,538)
Plant, equipment and vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	3,481	2,987
Property, plant and equipment at end of period	4,132	3,481	2,987
Plant, equipment and vehicles [member] | Cost [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	11,235	10,775
Exchange adjustments	(62)	1,100
Other additions	296	384
Disposals and write-offs	(685)	(1,422)
Reclassifications	1,186	512
Transfer to assets held for sale	(219)	(114)
Property, plant and equipment at end of period	11,751	11,235	10,775
Plant, equipment and vehicles [member] | Depreciation [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(7,410)	(7,415)
Exchange adjustments	110	(717)
Charge for the year	(689)	(640)
Disposals and write-offs	539	1,270
Transfer to assets held for sale	190	92
Property, plant and equipment at end of period	(7,260)	(7,410)	(7,415)
Plant, equipment and vehicles [member] | Impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(344)	(373)
Exchange adjustments	2	(37)
Disposals and write-offs	104	135
Impairment losses	(138)	(117)
Reversal of impairments	9	38
Transfer to assets held for sale	8	10
Property, plant and equipment at end of period	(359)	(344)	(373)
Plant, equipment and vehicles [member] | Depreciation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(7,754)
Property, plant and equipment at end of period	(7,619)	(7,754)
Assets in construction [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	3,104	2,564
Property, plant and equipment at end of period	2,458	3,104	2,564
Assets in construction [member] | Cost [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	3,168	2,670
Exchange adjustments	(45)	271
Other additions	1,219	1,043
Capitalised borrowing costs	30	30
Disposals and write-offs	(31)	(53)
Reclassifications	(1,826)	(761)
Transfer to assets held for sale	(14)	(32)
Property, plant and equipment at end of period	2,501	3,168	2,670
Assets in construction [member] | Impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(64)	(106)
Exchange adjustments	(2)	(11)
Disposals and write-offs	28	35
Impairment losses	(17)	(6)
Reversal of impairments	1	2
Transfer to assets held for sale	11	22
Property, plant and equipment at end of period	(43)	(64)	£ (106)
Assets in construction [member] | Depreciation and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment at beginning of period	(64)
Property, plant and equipment at end of period	£ (43)	£ (64)

XML

Property, Plant and Equipment - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about property, plant and equipment [line items]
Weighted average interest rate for capitalised borrowing costs	4.00%	3.80%
Property, plant and equipment	£ 10,860	£ 10,808	£ 9,668
Weighted average cost of capital post tax percentage	7.00%
Weighted average cost of capital pre-tax discount rate percentage	9.00%
Impairment loss recognised in profit or loss, property, plant and equipment	£ 327	180	346
Impairments charged or reversed	33	171
Cost [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	21,719	22,164	20,750
Assets in construction reclassified to intangible assets	(38)	(139)
Depreciation [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(10,296)	(10,669)	(10,329)
Impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(563)	(687)	(753)
Impairment loss recognised in profit or loss, property, plant and equipment	(349)	(258)
Impairments charged or reversed	17	78
Computer software [member]
Disclosure of detailed information about property, plant and equipment [line items]
Assets in construction reclassified to intangible assets	38	139
Cost of sales [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss recognised in profit or loss, property, plant and equipment	198	45
Research and development [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss recognised in profit or loss, property, plant and equipment	93	15
Selling, general and administrative expenses [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss recognised in profit or loss, property, plant and equipment	36	120
Major restructuring programmes [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss recognised in profit or loss, property, plant and equipment	278	151
Freeholds land and buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	3,896	3,887
Land and buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	4,270	4,223	4,117
Leased assets	375	336
Land and buildings [member] | Cost [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	7,467	7,761	7,305
Leased assets	630	590
Assets in construction reclassified to intangible assets	602	110
Land and buildings [member] | Depreciation [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(3,036)	(3,259)	(2,914)
Leased assets	255	253
Land and buildings [member] | Impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(161)	(279)	(274)
Leased assets	0	1
Impairment loss recognised in profit or loss, property, plant and equipment	(194)	(135)
Impairments charged or reversed	7	38
Land and buildings [member] | Property with leases of 50 years or more [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	338	294
Land and buildings [member] | Properties with leases less than 50 Years [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	36	42
Plant, equipment and vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	4,132	3,481	2,987
Leased assets	13	29
Plant, equipment and vehicles [member] | Cost [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	11,751	11,235	10,775
Leased assets	18	44
Assets in construction reclassified to intangible assets	1,186	512
Plant, equipment and vehicles [member] | Depreciation [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(7,260)	(7,410)	(7,415)
Leased assets	4	15
Plant, equipment and vehicles [member] | Impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(359)	(344)	£ (373)
Leased assets	1	0
Impairment loss recognised in profit or loss, property, plant and equipment	(138)	(117)
Impairments charged or reversed	£ 9	£ 38

XML

Goodwill - Summary of Changes in Goodwill (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill Beginning balance	£ 5,965	£ 5,162
Goodwill Ending Balance	5,734	5,965
Cost [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill Beginning balance	5,965	5,162
Exchange adjustments	(228)	814
Additions through business combinations (Note 38)		7
Transfer to assets held for sale	(3)	(18)
Goodwill Ending Balance	£ 5,734	£ 5,965

XML

Goodwill - Summary of Goodwill Allocated to Segments (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	£ 5,734	£ 5,965	£ 5,162
Pharmaceuticals [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	3,172	3,288
Vaccines [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	1,302	1,353
Consumer Healthcare [member]
Disclosure of reconciliation of changes in goodwill [line items]
Goodwill	£ 1,260	£ 1,324

XML

Goodwill - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2017
Disclosure of reconciliation of changes in goodwill [line items]
Description of basis on which unit's recoverable amount has been determined	The recoverable amounts of the cash generating units are assessed using a fair value less costs of disposal model. Fair value less costs of disposal is calculated using a discounted cash flow approach, with a post-tax discount rate applied to the projected risk-adjusted post-tax cash flows and terminal value.
Discount rate applied to cash flow projections	7.00%	7.00%
Pharmaceuticals [member]
Disclosure of reconciliation of changes in goodwill [line items]
Discount rate applied to cash flow projections		7.00%
Carrying value of assets with indefinite lives	£ 211	£ 228
Consumer Healthcare [member]
Disclosure of reconciliation of changes in goodwill [line items]
Discount rate applied to cash flow projections		7.00%
Carrying value of assets with indefinite lives	£ 9,030	£ 8,510

XML

Goodwill - Schedule of Discounted Cash Flow Models Used in Impairment Tests (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of reconciliation of changes in goodwill [line items]
Valuation basis	Fair value less costs of disposal
Key assumptions	Sales growth rates Profit margins Terminal growth rate Discount rate Taxation rate
Determination of assumptions	Growth rates are internal forecasts based on both internal and external market information. Margins reflect past experience, adjusted for expected changes. Terminal growth rates based on management's estimate of future long-term average growth rates. Discount rates based on Group WACC, adjusted where appropriate. Taxation rates based on appropriate rates for each region.
Period of specific projected cash flows	Five years
Discount rate	7.00%	7.00%
Pharmaceuticals [member]
Disclosure of reconciliation of changes in goodwill [line items]
Terminal growth rate	1.00%
Discount rate	7.00%
Vaccines [member]
Disclosure of reconciliation of changes in goodwill [line items]
Terminal growth rate	2.00%
Discount rate	7.00%
Consumer Healthcare [member]
Disclosure of reconciliation of changes in goodwill [line items]
Terminal growth rate	2.00%
Discount rate	7.00%

XML

Other Intangible Assets - Summary of Other Intangible Assets (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	£ 18,776	£ 16,672
Charge for the year	(934)	(796)	£ (738)
Impairment losses	690	22	217
Ending Balance	17,562	18,776	16,672
Brands with Indefinite Useful Life [Member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	9,245	7,952
Ending Balance	8,738	9,245	7,952
Cost [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	27,101	23,883
Exchange adjustments	(528)	2,616
Capitalised development costs	251	240
Capitalised borrowing costs	5	4
Additions through business combinations		102
Other additions	454	587
Disposals and asset write-offs	(255)	(418)
Transfer to assets held for sale	(135)	(52)
Reclassifications	38	139
Ending Balance	26,931	27,101	23,883
Cost [member] | Brands with Indefinite Useful Life [Member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	9,375	8,074
Exchange adjustments	(272)	1,320
Disposals and asset write-offs		(7)
Transfer to assets held for sale	(44)	(12)
Reclassifications	(66)
Ending Balance	8,993	9,375	8,074
Amortisation [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(6,391)	(5,457)
Exchange adjustments	166	(507)
Charge for the year	(934)	(796)
Disposals and asset write-offs	235	358
Transfer to assets held for sale	26	11
Ending Balance	(6,898)	(6,391)	(5,457)
Impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(1,934)	(1,754)
Exchange adjustments	113	(272)
Impairment losses	(680)	(22)
Disposals and asset write-offs	7	86
Transfer to assets held for sale	23	28
Ending Balance	(2,471)	(1,934)	(1,754)
Impairment [member] | Brands with Indefinite Useful Life [Member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(130)	(122)
Exchange adjustments	3	(3)
Impairment losses	(132)	(5)
Transfer to assets held for sale	4
Ending Balance	(255)	(130)	(122)
Amortisation and impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(8,325)
Ending Balance	(9,369)	(8,325)
Amortisation and impairment [member] | Brands with Indefinite Useful Life [Member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(130)
Ending Balance	(255)	(130)
Computer software [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	963	695
Ending Balance	1,054	963	695
Computer software [member] | Cost [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	2,156	2,028
Exchange adjustments	(37)	137
Capitalised borrowing costs	2	4
Other additions	233	238
Disposals and asset write-offs	(217)	(389)
Transfer to assets held for sale	(1)	(1)
Reclassifications	38	139
Ending Balance	2,174	2,156	2,028
Computer software [member] | Amortisation [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(1,184)	(1,294)
Exchange adjustments	25	(92)
Charge for the year	(163)	(152)
Disposals and asset write-offs	210	353
Transfer to assets held for sale	1	1
Ending Balance	(1,111)	(1,184)	(1,294)
Computer software [member] | Impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(9)	(39)
Exchange adjustments		(3)
Impairment losses	(2)	(2)
Disposals and asset write-offs	2	35
Ending Balance	(9)	(9)	(39)
Computer software [member] | Amortisation and impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(1,193)
Ending Balance	(1,120)	(1,193)
Licences and franchises [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	8,508	7,925
Ending Balance	7,658	8,508	7,925
Licences and franchises [member] | Cost [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	15,143	13,394
Exchange adjustments	(215)	1,139
Capitalised development costs	251	219
Capitalised borrowing costs	3
Additions through business combinations		102
Other additions	221	349
Disposals and asset write-offs	(38)	(21)
Transfer to assets held for sale	(90)	(39)
Ending Balance	15,275	15,143	13,394
Licences and franchises [member] | Amortisation [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(4,983)	(4,030)
Exchange adjustments	141	(410)
Charge for the year	(761)	(553)
Disposals and asset write-offs	25
Transfer to assets held for sale	25	10
Ending Balance	(5,553)	(4,983)	(4,030)
Licences and franchises [member] | Impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(1,652)	(1,439)
Exchange adjustments	110	(266)
Impairment losses	(546)	(15)
Disposals and asset write-offs	5	40
Transfer to assets held for sale	19	28
Ending Balance	(2,064)	(1,652)	(1,439)
Licences and franchises [member] | Amortisation and impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(6,635)
Ending Balance	(7,617)	(6,635)
Amortised brands [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	60	100
Ending Balance	112	60	100
Amortised brands [member] | Cost [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	427	387
Exchange adjustments	(4)	20
Capitalised development costs		21
Disposals and asset write-offs		(1)
Reclassifications	66
Ending Balance	489	427	387
Amortised brands [member] | Amortisation [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(224)	(133)
Exchange adjustments		(5)
Charge for the year	(10)	(91)
Disposals and asset write-offs		5
Ending Balance	(234)	(224)	(133)
Amortised brands [member] | Impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(143)	(154)
Disposals and asset write-offs		11
Ending Balance	(143)	(143)	£ (154)
Amortised brands [member] | Amortisation and impairment [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning Balance	(367)
Ending Balance	£ (377)	£ (367)

XML

Other Intangible Assets - Additional information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of detailed information about intangible assets [line items]
Weighted average interest rate for capitalised borrowing costs	4.00%	3.80%
Intangible assets, for which impairments have been charged or reversed	£ 300	£ 116
Discount rate equal to post-tax WACC	7.00%	7.00%
Bottom of range [member]
Disclosure of detailed information about intangible assets [line items]
Terminal growth rate, estimates of future long-term average growth rate	0.00%
Top of range [member]
Disclosure of detailed information about intangible assets [line items]
Terminal growth rate, estimates of future long-term average growth rate	5.00%
Internally generated [member]
Disclosure of detailed information about intangible assets [line items]
Net book value of computer software	£ 669	£ 620

XML

Other Intangible Assets - Schedule of Amortisation and Impairment Losses, Net of Reversals (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Amortisation of intangible assets	£ 934	£ 796	£ 738
Impairment of intangible assets, net of reversals	690	22	£ 217
Cost of sales [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Amortisation of intangible assets	578	582
Impairment of intangible assets, net of reversals	400	7
Selling, general and administrative expenses [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Amortisation of intangible assets	116	95
Impairment of intangible assets, net of reversals	2	2
Research and development [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Amortisation of intangible assets	240	119
Impairment of intangible assets, net of reversals	£ 278	£ 13

XML

Other Intangible Assets - Summary of Book Values of Largest Individual Items (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	£ 17,562	£ 18,776	£ 16,672
Licences and franchises [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	7,658	8,508	£ 7,925
Licences and franchises [member] | Meningitis Portfolio [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	2,450	2,511
Licences and franchises [member] | dolutegravir [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	1,389	1,487
Licences and franchises [member] | Benlysta [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	965	1,019
Licences and franchises [member] | Fluarix fluLaval [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	321	380
Licences and franchises [member] | HIV assets acquired from BMS [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	277	277
Licences and franchises [member] | Selzentry [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	162	188
Licences and franchises [member] | Okairos technology platform [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	202	173
Licences and franchises [member] | Others products [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Other intangible assets	£ 1,892	£ 2,473

XML

Other Intangible Assets - Summary of Book Values of Major Brands (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	£ 8,738	£ 9,245
Voltaren [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	2,716	2,847
Otrivin [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	1,380	1,447
Fenistil [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	648	680
Theraflu [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	441	462
Panadol [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	386	354
Sensodyne [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	265	243
Lamisil [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	289	304
Breathe Right [Member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	236	199
Stiefel trade name [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	228	211
Excedrin [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	185	194
Physiogel [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	166	166
Polident [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	112	103
Other Brands [member]
Disclosure of detailed information about intangible assets [line items]
Indefinite life brands	£ 1,686	£ 2,035

XML

Investments in Associates and Joint Ventures - Summary of Investments in Associates and Joint Ventures (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Beginning of investments	£ 263	£ 207
Exchange adjustments	(12)	45
Additions	15	11
Disposals	(92)
Distributions received	(2)	(3)
Other movements	(2)	(2)
(Loss)/profit after tax recognised in the consolidated income statement	13	5	£ 14
Beginning of investments	183	263	207
Joint ventures [member]
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Beginning of investments	19	20
Exchange adjustments	(2)	4
Additions		3
Distributions received	(1)	(2)
Other movements		(2)
(Loss)/profit after tax recognised in the consolidated income statement	(3)	(4)	(2)
Beginning of investments	13	19	20
Associates [member]
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Beginning of investments	244	187
Exchange adjustments	(10)	41
Additions	15	8
Disposals	(92)
Distributions received	(1)	(1)
Other movements	(2)
(Loss)/profit after tax recognised in the consolidated income statement	16	9
Beginning of investments	£ 170	£ 244	£ 187

XML

Investments in Associates and Joint Ventures - Additional Information (Detail) £ in Millions, shares in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£) _Associate shares	Dec. 31, 2016 GBP (£)
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Number of shares owned | shares	32
Percentage of shares owned	0.00%
Percentage of interest in royalty	85.00%
Innoviva Inc [member]
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Significant associate | _Associate	1
Market value of investment | £	£ 336	£ 278
Theravance Biopharma Inc [member]
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Percentage of common stock	17.80%

XML

Investments in Associates and Joint Ventures - Summary of Balance Sheet Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Non-current assets	£ 40,474	£ 42,370
Current assets	15,907	16,711
Current liabilities	(26,569)	(19,001)
Non-current liabilities	(26,323)	(35,117)
Net liabilities	(3,489)	(4,963)
Goodwill	5,734	5,965	£ 5,162
Innoviva Inc [member]
Disclosure of Investments in Associates and Joint Ventures [Line Items]
Non-current assets	124	146
Current assets	148	160
Current liabilities	(26)	(16)
Non-current liabilities	(426)	(575)
Net liabilities	(180)	(285)
Interest in associated undertaking	(57)	(84)
Goodwill	86	84
Fair value and other adjustments	118	138
Carrying value at 31 December	£ 147	£ 138

XML

Other Investments - Schedule of Other Investments (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Other investments 1 [abstract]
Beginning of other investments	£ 985	£ 1,255
Exchange adjustments	(64)	211
Additions	80	96
Net fair value movements	11	130
Impairment losses	(30)	(24)
Disposals	(64)	(683)
Ending of other investments	£ 918	£ 985

XML

Other Investments - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Other investments [line items]
Listed investments	£ 535	£ 580
Theravance Biopharma Inc [member]
Other investments [line items]
Percentage of common stock held	17.80%
Investment fair value	£ 199	£ 248

XML

Other Investments - Schedule of Carrying Value of Other Investments (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Other investments 1 [abstract]
Carrying value at original cost	£ 475	£ 515
Cumulative impairments recognised in the income statement	(283)	(314)
Subsequent fair value increases	210	282
Carrying value, ending balance	£ 402	£ 475

XML

Other Non-Current Assets - Summary of Other Non-Current Assets (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Miscellaneous non-current assets [abstract]
Amounts receivable under insurance contracts	£ 648	£ 602
Pension schemes in surplus	538	313
Other receivables	227	284
Total	£ 1,413	£ 1,199

XML

Inventories - Summary of Inventories (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Classes of current inventories [abstract]
Raw materials and consumables	£ 1,193	£ 1,068
Work in progress	2,381	2,299
Finished goods	1,983	1,735
Total	£ 5,557	£ 5,102

XML

Trade and Other Receivables - Summary of Trade and Other Receivables (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Trade and other receivables [abstract]
Trade receivables, net of provision for bad and doubtful debts	£ 4,672	£ 4,615
Accrued income	21	64
Other prepayments	308	335
Interest receivable	10	11
Employee loans and advances	19	17
Other receivables	970	984
Total trade and other receivables	£ 6,000	£ 6,026

XML

Trade and other receivables - Additional Information (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of trade and other receivables [line items]
Trade receivables	£ 4,672	£ 4,615
Other receivables	970	984
Associates and joint ventures [member]
Disclosure of trade and other receivables [line items]
Trade receivables	11	9
Other receivables	£ 7	£ 7

XML

Trade and Other Receivables - Summary of Bad and Doubtful Debt Provision (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Trade and other receivables [abstract]
Beginning Balance	£ 207	£ 167
Exchange adjustments	(4)	23
Charge for the year	31	77
Subsequent recoveries of amounts provided for	(79)	(59)
Utilised	(15)	(1)
Ending Balance	£ 140	£ 207

XML

Cash and cash equivalents - Summary of Cash and Cash Equivalents (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and cash equivalents [abstract]
Cash at bank and in hand	£ 826	£ 1,462
Short-term deposits	3,007	3,435
Total cash and cash equivalents	£ 3,833	£ 4,897	£ 5,830

XML

Assets Held for Sale - Summary of Assets Held for Sale (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets Held For Sale [Line Items]
Property, plant and equipment	£ 10,860	£ 10,808	£ 9,668
Goodwill	5,734	5,965	£ 5,162
Inventory	5,557	5,102
Total assets held for sale	113	215
Assets held for sale [member]
Assets Held For Sale [Line Items]
Property, plant and equipment	57	184
Goodwill		13
Other intangibles	49	12
Inventory	7	7
Other		(1)
Total assets held for sale	£ 113	£ 215

XML

Assets Held for Sale - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about intangible assets [line items]
Intangible impairments	£ 690	£ 22	£ 217
PP&E impairments	327	180	£ 346
PP&E impairment reversals	33	171
Financial assets written down to fair value	10,906	11,987
Other intangible assets [member]
Disclosure of detailed information about intangible assets [line items]
Intangible impairments	31
Intangible impairment reversals	21
PPE [Member]
Disclosure of detailed information about intangible assets [line items]
PP&E impairments	10
PP&E impairment reversals	15
Assets held for sale [member] | Level 3 [member]
Disclosure of detailed information about intangible assets [line items]
Financial assets written down to fair value	£ 63	£ 79

XML

Trade and Other Payables - Summary of Trade and Other Payables (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of trade and other payables [Line Items]
Trade payables	£ 3,528	£ 3,596
Wages and salaries	1,228	1,236
Social security	166	120
Deferred income	240	158
Customer return and rebate accruals	3,463	2,778
Other accruals	2,072	2,310
Total trade and other payables	20,970	11,964
Consumer Healthcare [member]
Disclosure of trade and other payables [Line Items]
Consumer Healthcare put option	8,606
Shionogi-ViiV Healthcare [member]
Disclosure of trade and other payables [Line Items]
Consumer Healthcare put option	1,304	1,319
Other payables	£ 363	£ 447

XML

Trade and Other Payables - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of trade and other payables [Line Items]
Trade and other current payables	£ 20,970	£ 11,964
Customer return and rebate accruals	£ 3,463	2,778
Discount rate payable stated percentage	7.00%
Reimbursement charges	£ 1,186	1,133
Estimated rebates, discounts or allowances payable to customers [member] | US Pharmaceuticals and vaccines [member]
Disclosure of trade and other payables [Line Items]
Customer return and rebate accruals	2,837	2,218
Associates and joint ventures [member]
Disclosure of trade and other payables [Line Items]
Trade and other current payables	£ 53	£ 36

XML

Trade and Other Payables - Summary of Increase/(Decrease) in Financial Liability and Loss/(Gain) in Income Statement (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£)
Novartis put option [member] | 10% increase in sales forecasts or sales multiple applied [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	£ 850
Loss/(gain) in Income statement	850
Novartis put option [member] | 10% decrease in sales forecasts or sales multiple applied [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	(850)
Loss/(gain) in Income statement	(850)
Novartis put option [member] | 10 cent appreciation of the US Dollar [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	88
Loss/(gain) in Income statement	88
Novartis put option [member] | 10 cent depreciation of US Dollar [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	(76)
Loss/(gain) in Income statement	(76)
Novartis put option [member] | 10 cent appreciation of the Euro [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	303
Loss/(gain) in Income statement	303
Novartis put option [member] | 10 cent depreciation of Euro [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	(254)
Loss/(gain) in Income statement	(254)
Pfizer's put option [member] | 10% increase in sales forecasts or sales multiple applied [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	150
Loss/(gain) in Income statement	150
Pfizer's put option [member] | 10% decrease in sales forecasts or sales multiple applied [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	(149)
Loss/(gain) in Income statement	(149)
Pfizer's put option [member] | 10 cent appreciation of the US Dollar [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	76
Loss/(gain) in Income statement	76
Pfizer's put option [member] | 10 cent depreciation of US Dollar [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	(66)
Loss/(gain) in Income statement	(66)
Pfizer's put option [member] | 10 cent appreciation of the Euro [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	44
Loss/(gain) in Income statement	44
Pfizer's put option [member] | 10 cent depreciation of Euro [member]
Disclosure of information about activities subject to rate regulation [line items]
Increase/(decrease) in financial liability	(37)
Loss/(gain) in Income statement	£ (37)

XML

Pensions and Other Post-employment Benefits - Summary of Pension and Other Post-employment Costs (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of pension and other post employment plan [Line Items]
Cost of sales	£ 10,342	£ 9,290	£ 8,853
Selling, general and administration	9,672	9,366	9,232
Research and development	4,476	3,628	3,560
Pension and other post-employment cost	616	541	467
Pension and other post-employment cost	616	541	467
UK Defined Benefit Plans [member]
Disclosure of pension and other post employment plan [Line Items]
Defined benefit pension and post retirement cost	198	205	177
US Defined Benefit Plans [member]
Disclosure of pension and other post employment plan [Line Items]
Defined benefit pension and post retirement cost	113	106	96
Other overseas pension schemes [member]
Disclosure of pension and other post employment plan [Line Items]
Pension and other post-employment cost	218	140	135
Pension and other post-employment cost	218	140	135
Unfunded post-retirement healthcare schemes [member]
Disclosure of pension and other post employment plan [Line Items]
Defined benefit pension and post retirement cost	87	90	59
Pension and other post-employment cost Analysed	87	90	59
Funded defined benefit/hybrid pension schemes [member]
Disclosure of pension and other post employment plan [Line Items]
Pension and other post-employment cost Analysed	335	304	291
Unfunded defined benefit pension schemes [member]
Disclosure of pension and other post employment plan [Line Items]
Pension and other post-employment cost Analysed	55	43	36
Defined benefit pension and post-retirement healthcare scheme. [member]
Disclosure of pension and other post employment plan [Line Items]
Cost of sales	162	135	127
Selling, general and administration	238	221	194
Research and development	77	81	65
Defined benefit pension and post retirement cost	477	437	386
Defined benefit schemes [member]
Disclosure of pension and other post employment plan [Line Items]
Pension and other post-employment cost Analysed	477	437	386
Defined contribution pension scheme [member]
Disclosure of pension and other post employment plan [Line Items]
Pension and other post-employment cost Analysed	£ 139	£ 104	£ 81

XML

Pensions and Other Post-employment Benefits - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Long term rate of improvement per year		1.25%
Special contributions		£ (444)	£ (481)	£ (408)
Pension schemes [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Employer contributions	£ 360
Post-retirement benefits [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Employer contributions	90
UK [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Rate of return on assets		55.00%
Rate of liability matching assets		45.00%
Special contributions		£ 136	191	85
UK [member] | Pension schemes [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Special contributions	£ 123
UK [member] | Other assets [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Loans on structured debt amount contributed to fair value of plan assets		£ (773)	(1,698)	(2,215)
US [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Rate of return on assets		55.00%
Rate of liability matching assets		45.00%
Special contributions		£ 78	£ 0	111
Assumption for future medical inflation		6.75%	7.00%
US [member] | 2025 and thereafter [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
Assumption for future medical inflation		5.00%
US [member] | Unfunded [member]
Disclosure of Pensions and Other Post-employment Benefits [Line Items]
US post retirement healthcare scheme obligation		£ 1,254	£ 1,463	£ 1,208

XML

Pensions and Other Post-employment Benefits - Summary of Average Life Expectancy Assumed (Detail)	12 Months Ended
	Dec. 31, 2017
UK [member] | Current. [member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Male Years	27 years 6 months
Female Years	29 years 6 months
UK [member] | Projected for 2037 [member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Male Years	29 years 1 month 6 days
Female Years	31 years 1 month 6 days
US [member] | Current. [member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Male Years	26 years 10 months 25 days
Female Years	28 years 7 months 6 days
US [member] | Projected for 2037 [member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Male Years	28 years 7 months 6 days
Female Years	30 years 3 months 19 days

XML

Pensions and Other Post-employment Benefits - Summary of Financial Assumptions in Assessing Defined Benefit Liabilities (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Defined Benefit Plan Actuarial Assumptions [line items]
Discount rate	7.00%
UK [member]
Disclosure Of Defined Benefit Plan Actuarial Assumptions [line items]
Rate of increase of future earnings	2.00%	2.00%	2.00%
Discount rate	2.50%	2.70%	3.80%
Expected pension increases	3.20%	3.20%	3.10%
Inflation rate	3.20%	3.20%	3.10%
US [member]
Disclosure Of Defined Benefit Plan Actuarial Assumptions [line items]
Rate of increase of future earnings	4.00%	4.00%	4.00%
Discount rate	3.60%	3.90%	4.20%
Cash balance credit/conversion rate	2.90%	3.20%	3.20%
Inflation rate	2.25%	2.25%	2.25%
Rest of world. [member]
Disclosure Of Defined Benefit Plan Actuarial Assumptions [line items]
Rate of increase of future earnings	2.80%	2.70%	2.70%
Discount rate	1.60%	1.60%	2.20%
Expected pension increases	2.20%	2.10%	2.00%
Cash balance credit/conversion rate	0.30%	0.30%	0.60%
Inflation rate	1.70%	1.50%	1.40%

XML

Pensions and Other Post-employment Benefits - Summary of Amounts Recorded in Income Statement and Statement of Comprehensive Income Related to Defined Benefit Pension and Post-retirement Healthcare Schemes (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	£ (280)	£ (246)	£ (254)
Past service cost	(37)	(54)	(17)
Net interest (credit)/cost	54	56	49
Gains from settlements		(28)	(8)
Remeasurement gains/(losses) recorded in the statement of comprehensive income	549	(475)	261
Pensions. [member] | Defined benefit pension and post-retirement healthcare scheme. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	280	246	254
Past service cost	37	54	17
Net interest (credit)/cost	54	56	49
Gains from settlements		(28)	(8)
Expenses	19	19	15
Net operating cost	390	347	327
Remeasurement gains/(losses) recorded in the statement of comprehensive income	485	(416)	199
Post-retirement benefits [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	(30)	(31)	(22)
Past service cost	2	(3)	8
Net interest (credit)/cost	(59)	(56)	(52)
Gains from settlements			7
Post-retirement benefits [member] | Defined benefit pension and post-retirement healthcare scheme. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	30	31	22
Past service cost	(2)	3	(8)
Net interest (credit)/cost	59	56	52
Gains from settlements			(7)
Net operating cost	87	90	59
Remeasurement gains/(losses) recorded in the statement of comprehensive income	64	(59)	62
UK [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	(79)	(70)	(77)
Past service cost	(37)	(52)	(25)
Net interest (credit)/cost	(340)	(394)	(388)
UK [member] | Defined benefit pension and post-retirement healthcare scheme. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	79	70	77
Past service cost	37	52	25
Net interest (credit)/cost	7	9	14
Expenses	7	7	7
Net operating cost	130	138	123
Remeasurement gains/(losses) recorded in the statement of comprehensive income	259	(165)	82
US [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	(70)	(66)	(67)
Past service cost		(1)	(2)
Net interest (credit)/cost	(135)	(135)	(117)
Gains from settlements			(1)
US [member] | Defined benefit pension and post-retirement healthcare scheme. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	70	66	67
Past service cost		1	2
Net interest (credit)/cost	31	27	22
Gains from settlements			1
Expenses	12	12	4
Net operating cost	113	106	96
Remeasurement gains/(losses) recorded in the statement of comprehensive income	240	(27)	(30)
Rest of world. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	(131)	(110)	(110)
Past service cost		(1)	10
Net interest (credit)/cost	(49)	(57)	(46)
Gains from settlements	4	138	25
Rest of world. [member] | Defined benefit pension and post-retirement healthcare scheme. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Current service cost	131	110	110
Past service cost		1	(10)
Net interest (credit)/cost	16	20	13
Gains from settlements		(28)	(9)
Expenses			4
Net operating cost	147	103	108
Remeasurement gains/(losses) recorded in the statement of comprehensive income	£ (14)	£ (224)	£ 147

XML

Pensions and Other Post-employment Benefits - Summary of Balance Sheet Presentation of Group Defined Benefit Pension Schemes and Other Post-retirement Benefits (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Post-retirement benefits/Pension schemes in deficit and surplus	£ 538	£ 313
Benefit plans	(3,539)	(4,090)	£ (3,229)
Other non-current assets [member] | Pension schemes [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Post-retirement benefits/Pension schemes in deficit and surplus	538	313	258
Pensions and other post-employment benefits [member] | Pension schemes [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Post-retirement benefits/Pension schemes in deficit and surplus	(2,043)	(2,397)	(1,842)
Pensions and other post-employment benefits [member] | Post-retirement benefits [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Post-retirement benefits/Pension schemes in deficit and surplus	£ (1,496)	£ (1,693)	£ (1,387)

XML

Pensions and Other Post-employment Benefits - Fair Values of Assets and Liabilities of UK and US Defined Benefit Pension Schemes Together with Aggregated Data for Other Defined Benefit Pension Schemes in Group (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Present value of scheme obligations	£ 19,785	£ 19,654	£ 16,119
Actual return on plan assets	(899)	(2,195)	526
Group.[member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Equities, listed	6,894	7,201	6,777
Equity, unlisted	13	14	1
Multi-asset funds	2,517	1,545	481
Property, unlisted	593	558	485
Corporate bonds, listed	1,220	601	1,054
Corporate bonds, unlisted	346	345	234
Government bonds, listed	6,128	7,719	6,535
Insurance contracts	1,556	1,493	1,194
Other assets	(987)	(1,906)	(2,226)
Fair value of assets	18,280	17,570	14,535
Present value of scheme obligations	(19,785)	(19,654)	(16,119)
Net surplus/(obligation)	(1,505)	(2,084)	(1,584)
Net surplus/(obligation)	(1,505)	(2,084)	(1,584)
Actual return on plan assets	1,369	2,725	(24)
Group.[member] | Other non-current assets [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Net surplus/(obligation)	538	313	258
Net surplus/(obligation)	538	313	258
Group.[member] | Pensions and other post-employment benefits [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Net surplus/(obligation)	(2,043)	(2,397)	(1,842)
Net surplus/(obligation)	(2,043)	(2,397)	(1,842)
UK [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Equities, listed	4,902	5,357	5,187
Multi-asset funds	2,517	1,545	481
Property, unlisted	352	314	302
Corporate bonds, listed	297	292	251
Corporate bonds, unlisted	326	321	232
Government bonds, listed	5,127	6,165	5,687
Insurance contracts	849	856	755
Other assets	(1,216)	(2,267)	(2,611)
Fair value of assets	13,154	12,583	10,284
Present value of scheme obligations	(13,101)	(12,884)	(10,601)	£ (10,991)
Net surplus/(obligation)	53	(301)	(317)
Net surplus/(obligation)	53	(301)	(317)
Actual return on plan assets	893	2,473	(17)
UK [member] | Other non-current assets [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Net surplus/(obligation)	470	276	232
Net surplus/(obligation)	470	276	232
UK [member] | Pensions and other post-employment benefits [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Net surplus/(obligation)	(417)	(577)	(549)
Net surplus/(obligation)	(417)	(577)	(549)
US [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Equities, listed	1,448	1,358	1,235
Property, unlisted	209	216	175
Corporate bonds, listed	820	213	727
Government bonds, listed	239	815	184
Other assets	158	288	180
Fair value of assets	2,874	2,890	2,501
Present value of scheme obligations	(3,445)	(3,752)	(3,134)	(3,133)
Net surplus/(obligation)	(571)	(862)	(633)
Net surplus/(obligation)	(571)	(862)	(633)
Actual return on plan assets	394	153	(30)
US [member] | Pensions and other post-employment benefits [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Net surplus/(obligation)	(571)	(862)	(633)
Net surplus/(obligation)	(571)	(862)	(633)
Rest of world. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Equities, listed	544	486	355
Equity, unlisted	13	14	1
Property, unlisted	32	28	8
Corporate bonds, listed	103	96	76
Corporate bonds, unlisted	20	24	2
Government bonds, listed	762	739	664
Insurance contracts	707	637	439
Other assets	71	73	205
Fair value of assets	2,252	2,097	1,750
Present value of scheme obligations	(3,239)	(3,018)	(2,384)	£ (2,176)
Net surplus/(obligation)	(987)	(921)	(634)
Net surplus/(obligation)	(987)	(921)	(634)
Actual return on plan assets	82	99	23
Rest of world. [member] | Other non-current assets [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Net surplus/(obligation)	68	37	26
Net surplus/(obligation)	68	37	26
Rest of world. [member] | Pensions and other post-employment benefits [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Net surplus/(obligation)	(1,055)	(958)	(660)
Net surplus/(obligation)	£ (1,055)	£ (958)	£ (660)

XML

Pensions and Other Post-employment Benefits - Summary of Movements in Fair Values of Assets (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Obligations at 1 January 2015	£ 19,785	£ 19,654	£ 16,119
Exchange adjustments		(40)	218	£ 11
Additions through business combinations				(164)
Service cost		(280)	(246)	(254)
Past service cost		(37)	(54)	(17)
Interest cost		54	56	49
Settlements and curtailments			(28)	(8)
Employer contributions		(444)	(481)	(408)
Obligations at 31 December 2015		19,785	19,654	16,119
UK [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Assets, beginning balance	13,154	12,583	10,284
Obligations at 1 January 2015	(13,101)	(12,884)	(10,601)	(10,991)
Service cost		(79)	(70)	(77)
Past service cost		(37)	(52)	(25)
Interest cost		(340)	(394)	(388)
Remeasurement		(301)	(2,253)	473
Employer contributions		136	191	85
Scheme participants' contributions		(4)	(4)	(4)
Benefits paid		544	490	411
Assets at 31 December 2016		13,154	12,583	10,284
Obligations at 31 December 2015		(13,101)	(12,884)	(10,601)
UK [member] | Plan Assets [Member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Assets, beginning balance	13,154	12,583	10,284	10,551
Interest cost		333	385	374
Expenses		(7)	(7)	(7)
Remeasurement		560	2,088	(391)
Employer contributions		225	319	164
Scheme participants' contributions		4	4	4
Benefits paid		(544)	(490)	(411)
Assets at 31 December 2016		13,154	12,583	10,284
US [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Assets, beginning balance	2,874	2,890	2,501
Obligations at 1 January 2015	(3,445)	(3,752)	(3,134)	(3,133)
Exchange adjustments		(305)	586	184
Service cost		(70)	(66)	(67)
Past service cost			(1)	(2)
Interest cost		(135)	(135)	(117)
Settlements and curtailments				(1)
Remeasurement		(50)	(72)	95
Employer contributions		78	0	111
Benefits paid		257	242	275
Assets at 31 December 2016		2,874	2,890	2,501
Obligations at 31 December 2015		(3,445)	(3,752)	(3,134)
US [member] | Plan Assets [Member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Assets, beginning balance	2,874	2,890	2,501	2,531
Exchange adjustments		(244)	459	147
Interest cost		104	108	95
Expenses		(12)	(12)	(4)
Remeasurement		290	45	(125)
Employer contributions		103	31	132
Benefits paid		(257)	(242)	(275)
Assets at 31 December 2016		2,874	2,890	2,501
Rest of world. [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Assets, beginning balance	2,252	2,097	1,750
Obligations at 1 January 2015	(3,239)	(3,018)	(2,384)	(2,176)
Exchange adjustments		45	396	(78)
Additions through business combinations				(397)
Service cost		(131)	(110)	(110)
Past service cost			(1)	10
Interest cost		(49)	(57)	(46)
Settlements and curtailments		4	138	25
Remeasurement		(63)	(286)	157
Scheme participants' contributions		(17)	(14)	(14)
Benefits paid		80	92	89
Assets at 31 December 2016		2,252	2,097	1,750
Obligations at 31 December 2015		(3,239)	(3,018)	(2,384)
Rest of world. [member] | Plan Assets [Member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Assets, beginning balance	2,252	2,097	1,750	1,529
Exchange adjustments		24	305	(52)
Additions through business combinations				233
Interest cost		33	37	33
Expenses				(4)
Settlements and curtailments		(4)	(110)	(16)
Remeasurement		49	62	(10)
Employer contributions		116	131	112
Scheme participants' contributions		17	14	14
Benefits paid		(80)	(92)	(89)
Assets at 31 December 2016		2,252	2,097	1,750
Pension schemes [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Obligations at 1 January 2015	(19,785)	(19,654)	(16,119)	(16,300)
Exchange adjustments		(260)	982	106
Additions through business combinations				(397)
Service cost		(280)	(246)	(254)
Past service cost		(37)	(54)	(17)
Interest cost		(524)	(586)	(551)
Settlements and curtailments		4	138	24
Remeasurement		(414)	(2,611)	725
Scheme participants' contributions		(21)	(18)	(18)
Benefits paid		881	824	775
Obligations at 31 December 2015		(19,785)	(19,654)	(16,119)
Pension schemes [member] | Plan Assets [Member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Assets, beginning balance	18,280	17,570	14,535	14,611
Exchange adjustments		(220)	764	95
Additions through business combinations				233
Interest cost		470	530	502
Expenses		(19)	(19)	(15)
Settlements and curtailments		(4)	(110)	(16)
Remeasurement		899	2,195	(526)
Employer contributions		444	481	408
Scheme participants' contributions		21	18	18
Benefits paid		(881)	(824)	(775)
Assets at 31 December 2016		18,280	17,570	14,535
Pension schemes [member] | UK [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Employer contributions	123
Post-retirement benefits [member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Obligations at 1 January 2015	£ (1,496)	(1,693)	(1,387)	(1,397)
Exchange adjustments		(119)	248	64
Additions through business combinations				(11)
Service cost		(30)	(31)	(22)
Past service cost		2	(3)	8
Interest cost		(59)	(56)	(52)
Settlements and curtailments				7
Remeasurement		64	(59)	62
Scheme participants' contributions		(17)	(17)	(14)
Benefits paid		118	108	96
Obligations at 31 December 2015		(1,496)	(1,693)	(1,387)
Post-retirement benefits [member] | Plan Assets [Member]
Disclosure Of Defined Benefit Pension And Post Retirement [Line Items]
Employer contributions		101	91	82
Scheme participants' contributions		17	17	14
Benefits paid		£ (118)	£ (108)	£ (96)

XML

Pensions and Other Post-employment Benefits - Summary of Analysis of Defined Benefit Pension Obligation (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of defined benefit plans [line items]
Defined benefit obligation	£ (19,785)	£ (19,654)	£ (16,119)
Funded [member]
Disclosure of defined benefit plans [line items]
Defined benefit obligation	(19,052)	(18,974)	(15,552)
Unfunded [member]
Disclosure of defined benefit plans [line items]
Defined benefit obligation	£ (733)	£ (680)	£ (567)

XML

Pensions and Other Post-employment Benefits - Summary of Movement in Net Defined Benefit Liability (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of defined benefit plans [abstract]
Beginning of net defined benefit liability	£ (2,084)	£ (1,584)	£ (1,689)
Exchange adjustments	40	(218)	(11)
Additions through business combinations			(164)
Service cost	(280)	(246)	(254)
Past service cost	(37)	(54)	(17)
Interest cost	(54)	(56)	(49)
Settlements and curtailments		28	8
Remeasurements:
Return on plan assets, excluding amounts included in interest	899	2,195	(526)
Gain/(loss) from change in demographic assumptions	209	85	120
(Loss)/gain from change in financial assumptions	(555)	(2,770)	362
Experience (losses)/gains	(68)	74	243
Employer contributions	444	481	408
Expenses/other movements	(19)	(19)	(15)
Ending of net defined benefit liability	£ (1,505)	£ (2,084)	£ (1,584)

XML

Pensions and Other Post-Employment Benefits - Summary of Remeasurements Within Post-Retirement Benefits (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of net defined benefit liability (asset) [line items]
Gain from change in demographic assumptions	£ (209)	£ (85)	£ (120)
(Loss)/gain from change in financial assumptions	555	2,770	(362)
Experience gains/(losses)	68	(74)	(243)
Post-retirement benefits [member]
Disclosure of net defined benefit liability (asset) [line items]
Gain from change in demographic assumptions	47		15
(Loss)/gain from change in financial assumptions	(1)	(81)	59
Experience gains/(losses)	18	22	(12)
Total	£ 64	£ (59)	£ 62

XML

Pensions and Other Post-Employment Benefits - Summary of Defined Benefit Pension Obligation Analysed by Membership Category (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of defined benefit plans [line items]
Defined benefit pension obligation analysed by membership category	£ 19,785	£ 19,654	£ 16,119
Pensions. [member]
Disclosure of defined benefit plans [line items]
Defined benefit pension obligation analysed by membership category	19,785	19,654	17,710
Active [member] | Pensions. [member]
Disclosure of defined benefit plans [line items]
Defined benefit pension obligation analysed by membership category	4,611	4,576	5,510
Retired [member] | Pensions. [member]
Disclosure of defined benefit plans [line items]
Defined benefit pension obligation analysed by membership category	9,805	9,574	7,969
Deferred [member] | Pensions. [member]
Disclosure of defined benefit plans [line items]
Defined benefit pension obligation analysed by membership category	£ 5,369	£ 5,504	£ 4,231

XML

Pensions and Other Post-Employment Benefits - Summary of Post-Retirement Benefit Obligation Analysed by Membership Category (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of defined benefit plans [line items]
Post-retirement benefit obligation analysed by membership category	£ (19,785)	£ (19,654)	£ (16,119)
Post-retirement benefits [member]
Disclosure of defined benefit plans [line items]
Post-retirement benefit obligation analysed by membership category	1,496	1,693	1,387	£ 1,397
Active [member] | Post-retirement benefits [member]
Disclosure of defined benefit plans [line items]
Post-retirement benefit obligation analysed by membership category	514	594	499
Retired [member] | Post-retirement benefits [member]
Disclosure of defined benefit plans [line items]
Post-retirement benefit obligation analysed by membership category	981	£ 1,099	887
Deferred [member] | Post-retirement benefits [member]
Disclosure of defined benefit plans [line items]
Post-retirement benefit obligation analysed by membership category	£ 1		£ 1

XML

Pensions and Other Post-Employment Benefits - Summary of Weighted Average Duration Defined Benefit Obligation (Detail) - yr	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pensions. [member]
Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Line Items]
Weighted average duration of the defined benefit obligation	16	16	16
Post retirement benefit [Member]
Disclosure of Information About Maturity Profile of Defined Benefit Obligation [Line Items]
Weighted average duration of the defined benefit obligation	11	12	12

XML

Pensions and Other Post-Employment Benefits - Summary of Changes in Assumptions Used on Benefit Obligations, Defined Benefit Pension and Post Retirement Costs (Details) (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£)
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase in annual pension cost	£ 29
Actuarial assumption of discount rates [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase in annual pension cost	29
Increase/Decrease in annual post-retirement benefits cost	(1)
Increase in pension obligation	800
Increase in post-retirement benefits obligation	41
Actuarial assumption of life expectancy rates [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase in annual pension cost	20
Increase/Decrease in annual post-retirement benefits cost	2
Increase in pension obligation	608
Increase in post-retirement benefits obligation	39
Future assumptions rate for healthcare plans [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase/Decrease in annual post-retirement benefits cost	2
Increase in post-retirement benefits obligation	68
Actuarial assumption of expected rates of inflation [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase in annual pension cost	19
Increase in pension obligation	£ 502

XML

Pensions and Other Post-Employment Benefits - Summary of Changes in Assumptions Used on Benefit Obligations, Defined Benefit Pension and Post Retirement Costs (Details) (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Decrease in discount rate	7.00%
Actuarial assumption of discount rates [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Decrease in discount rate	0.25%
Actuarial assumption of life expectancy rates [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase in life expectancy	1 year
Future assumptions rate for healthcare plans [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase in the rate of future healthcare inflation	1.00%
Actuarial assumption of expected rates of inflation [Member]
Disclosure of Sensitivity Analysis for Actuarial Assumptions [Line Items]
Increase in inflation	0.25%

XML

Other Provisions - Summary of Other Provisions (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Disclosure of other provisions [line items]
Other provisions, beginning balance	£ 1,500
Exchange adjustments	(59)
Charge for the year	551
Reversed unused	(89)
Unwinding of discount	16
Utilised	(629)
Reclassifications and other movements	(7)
Transfer to Pension obligations	(18)
Other provisions, ending balance	1,265
To be settled within one year		£ 629	£ 848
To be settled after one year		636	652
Other provisions	1,500	1,265	1,500
Legal and other disputes [member]
Disclosure of other provisions [line items]
Other provisions, beginning balance	344
Exchange adjustments	(29)
Charge for the year	173
Reversed unused	(7)
Unwinding of discount	2
Utilised	(288)
Reclassifications and other movements	(9)
Other provisions, ending balance	186
To be settled within one year		138
To be settled after one year		48
Other provisions	344	186	344
Major Restructuring Programmes [Member]
Disclosure of other provisions [line items]
Other provisions, beginning balance	554
Exchange adjustments	(16)
Charge for the year	259
Reversed unused	(43)
Unwinding of discount	4
Utilised	(233)
Reclassifications and other movements	(3)
Transfer to Pension obligations	(18)
Other provisions, ending balance	504
To be settled within one year		292
To be settled after one year		212
Other provisions	554	504	554
Employee Related Provisions [Member]
Disclosure of other provisions [line items]
Other provisions, beginning balance	306
Exchange adjustments	(8)
Charge for the year	50
Reversed unused	(3)
Utilised	(41)
Other provisions, ending balance	304
To be settled within one year		90
To be settled after one year		214
Other provisions	306	304	306
Other Provision [Member]
Disclosure of other provisions [line items]
Other provisions, beginning balance	296
Exchange adjustments	(6)
Charge for the year	69
Reversed unused	(36)
Unwinding of discount	10
Utilised	(67)
Reclassifications and other movements	5
Other provisions, ending balance	271
To be settled within one year		109
To be settled after one year		162
Other provisions	£ 296	£ 271	£ 296

XML

Other provisions - Additional Information (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of other provisions [line items]
Charges on other provisions	£ 551,000,000
Discount on the provisions	2,000,000	£ 1,000,000
Short term legal proceedings	138,000,000
Legal proceedings and other disputes provision estimated	0	0
Pension augmentations arising from staff redundancies	£ 18,000,000	23,000,000
Period for amounts provided are expected to be utilised	2 years
Provision for employee benefits	£ 6,000,000	40,000,000
Onerous property lease provisions	38,000,000	39,000,000
Disabled employees [member]
Disclosure of other provisions [line items]
Provision for employee benefits	108,000,000	£ 135,000,000
Legal and other disputes [member]
Disclosure of other provisions [line items]
Charges on other provisions	£ 173,000,000

XML

Other Non-current Liabilities - Summary of Other Noncurrent Liabilities (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Other non-current liabilities [abstract]
Accruals and deferred income	£ 104	£ 66
Consumer Healthcare put option liability		7,420
Other payables	877	959
Other noncurrent liabilities	£ 981	£ 8,445

XML

Net Debt - Schedule of Current Assets, Short and Long Term Borrowings (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Liquid investments	£ 78	£ 89
Cash and cash equivalents	3,833	4,897	£ 5,830
Current assets	15,907	16,711
Short-term borrowings:
Commercial paper	(529)	(1,094)
Bank loans and overdrafts	(236)	(332)
Short-term borrowings	(2,825)	(4,129)
Long-term borrowings:
Long-term borrowings	(14,264)	(14,661)
Net debt	(13,178)	(13,804)	£ (10,727)	£ (14,377)
Short-term borrowings [member]
Short-term borrowings:
Obligations under finance leases	(23)	(23)
Long Term Borrowings [Member]
Long-term borrowings:
Obligations under finance leases	(43)	(41)
Other LongTerm Borrowings [Member]
Long-term borrowings:
Long-term borrowings	(49)
New York Stock Exchange [Member] | 1.50% US Medium Term Note 2017 [Member]
Short-term borrowings:
Short-term borrowings		(1,612)
New York Stock Exchange [Member] | 5.65% US Medium Term Note 2018 [Member]
Short-term borrowings:
Short-term borrowings	(2,037)
Long-term borrowings:
Long-term borrowings		(2,216)
New York Stock Exchange [Member] | 2.85% US Medium Term Note 2022 [Member]
Long-term borrowings:
Long-term borrowings	(1,474)	(1,603)
New York Stock Exchange [Member] | 2.8% US Medium Term Note 2023 [Member]
Long-term borrowings:
Long-term borrowings	(919)	(999)
New York Stock Exchange [Member] | 6.375% US Medium Term Note 2038 [Member]
Long-term borrowings:
Long-term borrowings	(2,021)	(2,199)
New York Stock Exchange [Member] | 4.2% US Medium Term Note 2043 [Member]
Long-term borrowings:
Long-term borrowings	(363)	(395)
London Stock Exchange [Member] | 5.625% European Medium Term Note 2017 [Member]
Short-term borrowings:
Short-term borrowings		(1,068)
London Stock Exchange [Member] | 0.625% European Medium Term Notes 2019 [Member]
Long-term borrowings:
Long-term borrowings	(1,324)	(1,276)
London Stock Exchange [Member] | Zero Percent European Medium Term Notes Two Thousand twenty [Member]
Long-term borrowings:
Long-term borrowings	(1,060)
London Stock Exchange [Member] | 1.375% European Medium Term Notes 2024 [Member]
Long-term borrowings:
Long-term borrowings	(876)	(845)
London Stock Exchange [Member] | 4.00% European Medium Term Note 2025 [Member]
Long-term borrowings:
Long-term borrowings	(659)	(635)
London Stock Exchange [Member] | One Percent European Medium Term Notes Two Thousand twenty six [Member]
Long-term borrowings:
Long-term borrowings	(617)
London Stock Exchange [Member] | 3.375% European Medium Term Note 2027 [Member]
Long-term borrowings:
Long-term borrowings	(593)	(593)
London Stock Exchange [Member] | One point three seven five Percent European Medium Term Notes Two Thousand twenty nine [Member]
Long-term borrowings:
Long-term borrowings	(439)
London Stock Exchange [Member] | 5.25% European Medium Term Note 2033 [Member]
Long-term borrowings:
Long-term borrowings	(986)	(986)
London Stock Exchange [Member] | 5.375% US Medium Term Note 2034 [Member]
Long-term borrowings:
Long-term borrowings	(368)	(401)
London Stock Exchange [Member] | 6.375% European Medium Term Note 2039 [Member]
Long-term borrowings:
Long-term borrowings	(695)	(695)
London Stock Exchange [Member] | 5.25% European Term Note 2042 [Member]
Long-term borrowings:
Long-term borrowings	(989)	(988)
London Stock Exchange [Member] | 4.25% European Medium Term Note 2045 [Member]
Long-term borrowings:
Long-term borrowings	(789)	(789)
Net debt [member]
Current assets:
Liquid investments	78	89
Cash and cash equivalents	3,833	4,897
Current assets	£ 3,911	£ 4,986

XML

Net Debt - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017 GBP (£)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 GBP (£)	Dec. 31, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Disclosure of debt [Line Items]
Effective Interest rate on liquid investment	1.00%		0.70%		1.00%	0.70%
Effective Interest rate on cash and cash equivalents	1.30%	1.30%	1.30%	1.30%
Commercial paper issued	£ 529,000,000		£ 1,094,000,000
Weighted average interest rate on current bank loans and overdrafts	4.65%		3.47%		4.65%	3.47%
Average effective pre-swap interest rate notes as short	5.92%				5.92%
Long-term borrowings	£ 14,264,000,000		£ 14,661,000,000
Average effective pre-swap interest rate notes	3.60%	3.60%	4.10%	4.10%
Other non current assets	£ 1,413,000,000		£ 1,199,000,000
US commercial paper program [member]
Disclosure of debt [Line Items]
Commercial paper authorized	7,400,000,000				$ 10,000,000,000
Commercial paper issued	£ 500,000,000		1,100,000,000		700,000,000	$ 1,400,000,000
Bottom of range [member]
Disclosure of debt [Line Items]
Repayment dates	2023	2023
Top of range [member]
Disclosure of debt [Line Items]
Repayment dates	2045	2045
Floating interest rate [member]
Disclosure of debt [Line Items]
Liquid investment	£ 78,000,000		89,000,000
Interest income	3,832,000,000		4,584,000,000
Fixed interest rate [member]
Disclosure of debt [Line Items]
Liquid investment	0		0
Interest income	£ 1,000,000		£ 3,000,000
Commercial paper [member]
Disclosure of debt [Line Items]
Weighted average interest rate of borrowings	1.53%	1.53%	0.88%	0.88%
Letter of credit 1 [member]
Disclosure of debt [Line Items]
Pledged investments value	£ 78,000,000	$ 105,000,000	£ 85,000,000	$ 105,000,000
Other non current assets	20,000,000		23,000,000
Five -year commitment facility [member] | US commercial paper program [member]
Disclosure of debt [Line Items]
Credit Facility available amount	1,900,000,000
364 day committed facilities [member] | US commercial paper program [member]
Disclosure of debt [Line Items]
Credit Facility available amount	1,900,000,000				$ 2,500,000,000
Later than five years [member]
Disclosure of debt [Line Items]
Long-term borrowings	£ 10,300,000,000		£ 11,100,000,000
Later than five years [member] | Bottom of range [member]
Disclosure of debt [Line Items]
Interest at effective rates	1.07%	1.07%
Later than five years [member] | Top of range [member]
Disclosure of debt [Line Items]
Interest at effective rates	6.66%	6.66%

XML

Net Debt - Schedule of Finance Lease Obligations (Detail) - GBP (£)	Dec. 31, 2017	Dec. 31, 2016
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total future rental payments	£ 78	£ 67
Future finance charges	(12)	(3)
Total finance lease obligations	66	64
Not later than one year [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total future rental payments	25	25
Between one and two years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total future rental payments	29	23
Between two and three years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total future rental payments	9	12
Between Three and Four Years [Member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total future rental payments	3	£ 7
Between four and five years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total future rental payments	2
Later than five years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Total future rental payments	£ 10

XML

Contingent Liabilities - Additional Information (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of contingent liabilities [abstract]
Contingent liabilities, comprising guarantees, discounted bills and other items	£ 434	£ 281
Financial assets were pledged as collateral for contingent liabilities	£ 2	£ 1

XML

Share Capital and Share Premium Account - Summary of Share Capital and Share Premium (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure Of Classes Of Share Capital And Share Premium [Line Items]
Share capital issued and fully paid beginning balance	5,368,316,062	5,361,307,647	5,355,297,232
Shares Authorised	10,000,000,000	10,000,000,000	10,000,000,000
Issued under employee share schemes	4,237,758	7,008,415	6,010,415
Ordinary shares acquired by ESOP Trusts	0	0
Share capital issued and fully paid ending balance	5,372,553,820	5,368,316,062	5,361,307,647
Equity at beginning of period	£ 4,963,000,000	£ 8,878,000,000	£ 4,936,000,000
Issued under employee share schemes	56,000,000	89,000,000	73,000,000
Equity at end of period	3,489,000,000	4,963,000,000	8,878,000,000
Share premium [member]
Disclosure Of Classes Of Share Capital And Share Premium [Line Items]
Equity at beginning of period	2,954,000,000	2,831,000,000	2,759,000,000
Issued under employee share schemes	55,000,000	87,000,000	72,000,000
Ordinary shares acquired by ESOP Trusts	10,000,000	36,000,000
Equity at end of period	3,019,000,000	2,954,000,000	2,831,000,000
Share capital [member]
Disclosure Of Classes Of Share Capital And Share Premium [Line Items]
Equity at beginning of period	1,342,000,000	1,340,000,000	1,339,000,000
Issued under employee share schemes	1,000,000	2,000,000	1,000,000
Equity at end of period	1,343,000,000	1,342,000,000	1,340,000,000
Share capital [member] | Ordinary shares [member]
Disclosure Of Classes Of Share Capital And Share Premium [Line Items]
Shares Authorised, value	2,500,000,000	2,500,000,000	2,500,000,000
Equity at beginning of period	1,342,000,000	1,340,000,000	1,339,000,000
Issued under employee share schemes	1,000,000	2,000,000	1,000,000
Equity at end of period	£ 1,343,000,000	£ 1,342,000,000	£ 1,340,000,000

XML

Share Capital and Share Premium Account - Summary of Share Capital and Share Premium (Parenthetical) (Detail)	Dec. 31, 2017 £ / shares
Disclosure Of Classes Of Share Capital And Share Premium [Abstract]
Ordinary price per share	£ 0.25

XML

Share Capital and Share Premium Account - Summary of Share Capital (Detail)	12 Months Ended
	Dec. 31, 2017 shares	Dec. 31, 2016 shares
Disclosure Of Classes Of Share Capital And Share Premium [Abstract]
Number of shares issuable under employee share schemes	38,647	71,382
Number of unissued shares not under option	4,588,799	4,560,302

XML

Share Capital and Share Premium Account - Additional Information (Detail)	Dec. 31, 2017 shares
Employee share ownership plan [member]
Disclosure Of Classes Of Share Capital And Share Premium [Line Items]
Share capital issued	66,696,677
Treasury shares [member]
Disclosure Of Classes Of Share Capital And Share Premium [Line Items]
Share capital issued	414,605,950
Free issue [member]
Disclosure Of Classes Of Share Capital And Share Premium [Line Items]
Share capital issued	4,891,251,193

XML

Movements in Equity - Additional Information (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Retained earnings and other reserves	£ (4,430)	£ (3,172)	£ 943
Other reserve	2,047	2,220	2,340	£ 2,239
Associates and joint ventures [member]
Retained earnings and other reserves	334	329	283
Merger and premerger reserves [member]
Other reserve	1,849	1,849	1,849
Capital redemption reserve [member]
Other reserve	£ 280	£ 280	£ 280

XML

Movements in Equity - Summary of Cumulative Translation Exchange in Equity (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Beginning balance	£ 389	£ (860)	£ (250)
Exchange movements on overseas net assets	313	1,249	(610)
Reclassification of exchange on liquidation or disposal of overseas subsidiaries	109
Ending balance	811	389	(860)
Retained earnings [member]
Beginning balance	(128)	(761)	(137)
Exchange movements on overseas net assets	462	633	(624)
Reclassification of exchange on liquidation or disposal of overseas subsidiaries	109
Ending balance	443	(128)	(761)
Fair value reserve [member]
Beginning balance	23	10	4
Exchange movements on overseas net assets		13	6
Ending balance	23	23	10
Non- controlling interests [member]
Beginning balance	494	(109)	(117)
Exchange movements on overseas net assets	(149)	603	8
Ending balance	£ 345	£ 494	£ (109)

XML

Movements in Equity - Analysis of Other Comprehensive Income by Equity Category (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges	£ 462	£ 646	£ (618)
Reclassification of exchange on liquidation or disposal of overseas subsidiaries	109
Fair value movements on available-for-sale investments	(14)	251	416
Deferred tax on fair value movements on available-for-sale investments	47		(91)
Reclassification of fair value movements on available-for-sale investments	(42)	(245)	(346)
Deferred tax reversed on reclassification of available for sale investments	(18)	51	36
Reclassification of cash flow hedges to income statement		1	2
Fair value movements on cash flow hedges	(10)	2	2
Share of other comprehensive expense of associates and joint ventures			(77)
Deferred tax on fair value movements on cash flow hedges		2
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests	(149)	603	8
Remeasurement gains on defined benefit plans	549	(475)	261
Tax on remeasurement gains in defined benefit plans	(221)	126	(80)
Other comprehensive (expense)/income for the year	713	962	(487)
Retained earnings [member]
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges	462	633	(624)
Reclassification of exchange on liquidation or disposal of overseas subsidiaries	109
Share of other comprehensive expense of associates and joint ventures			(77)
Items that will not be reclassified to income statement:
Remeasurement gains on defined benefit plans	549	(475)	261
Tax on remeasurement gains in defined benefit plans	(221)	126	(80)
Other comprehensive (expense)/income for the year	899	284	(520)
Other reserves [member]
Items that may be subsequently reclassified to income statement:
Exchange movements on overseas net assets and net investment hedges		13	6
Fair value movements on available-for-sale investments	(14)	251	416
Deferred tax on fair value movements on available-for-sale investments	47		(91)
Reclassification of fair value movements on available-for-sale investments	(42)	(245)	(346)
Deferred tax reversed on reclassification of available for sale investments	(18)	51	36
Reclassification of cash flow hedges to income statement		1	2
Fair value movements on cash flow hedges	(10)	2	2
Deferred tax on fair value movements on cash flow hedges		2
Items that will not be reclassified to income statement:
Other comprehensive (expense)/income for the year	(37)	75	25
Non- controlling interests [member]
Items that will not be reclassified to income statement:
Exchange movements on overseas net assets of non-controlling interests	(149)	603	8
Other comprehensive (expense)/income for the year	£ (149)	£ 603	£ 8

XML

Movements in Equity - Analysis of Other Reserves (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other reserves, beginning balance	£ 2,220	£ 2,340	£ 2,239
Transferred to income and expense in the year on disposals	(20)	(284)	(354)
Transferred to income and expense in the year on impairments		23	10
Net fair value movement in the year	(17)	336	369
Ordinary shares acquired by ESOP Trusts	(656)	(576)	(99)
Write-down of shares held by ESOP Trusts	520	381	175
Other reserves, ending balance	2,047	2,220	2,340
ESOP trust shares [member]
Other reserves, beginning balance	(286)	(75)	(151)
Transferred to income and expense in the year on disposals	22	(16)
Ordinary shares acquired by ESOP Trusts	(656)	(576)	(99)
Write-down of shares held by ESOP Trusts	520	381	175
Other reserves, ending balance	(400)	(286)	(75)
Fair value reserve [member]
Other reserves, beginning balance	380	295	274
Transferred to income and expense in the year on disposals	(42)	(268)	(356)
Transferred to income and expense in the year on impairments		23	10
Net fair value movement in the year	(9)	330	367
Other reserves, ending balance	329	380	295
Cash Flow Hedges Reserve [Member]
Other reserves, beginning balance	(3)	(9)	(13)
Transferred to income and expense in the year on disposals			2
Net fair value movement in the year	(8)	6	2
Other reserves, ending balance	(11)	(3)	(9)
Other reserves [member]
Other reserves, beginning balance	2,129	2,129	2,129
Other reserves, ending balance	£ 2,129	£ 2,129	£ 2,129

XML

Related Party Transactions - Additional Information (Detail) - GBP (£) shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Japan Vaccine Company Limited [member]
Disclosure of transactions between related parties [line items]
Sale of vaccine product	£ 41,000,000	£ 43,000,000
Trading balance receivable	11,000,000	9,000,000
Trading balance payable	0	0
Loans outstanding	£ 7,000,000
Innoviva incorporation [member]
Disclosure of transactions between related parties [line items]
Number of shares owned	32
Percentage of shares owned	31.40%
Royalty charge	£ 173,000,000	108,000,000
Royalty payable	£ 53,000,000	£ 36,000,000
Joint ventures where entity is venturer [member] | Japan Vaccine Company Limited [member]
Disclosure of transactions between related parties [line items]
Ownership interest	50.00%
Medicxi Ventures I Limited Partner [member]
Disclosure of transactions between related parties [line items]
Loans outstanding	£ 7,000,000
Index ventures life VI [member]
Disclosure of transactions between related parties [line items]
Loans outstanding	£ 8,000,000

XML

Adjustments Reconciling Profit After Tax to Operating Cash Flows - Summary of Cash Generated from Operations (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Adjustments to reconcile profit (loss) [abstract]
Profit after tax	£ 2,169	£ 1,062	£ 8,372
Tax on profits	1,356	877	2,154
Share of after tax profits of associates and joint ventures	(13)	(5)	(14)
Finance expense net of finance income	669	664	653
Depreciation	988	978	892
Amortisation of intangible assets	934	796	738
Impairment and assets written off	1,061	226	822
Profit on sale of businesses	(157)	(5)	(9,308)
Profit on sale of intangible assets	(46)	(178)	(349)
Profit on sale of investments in associates	(94)		(843)
Profit on sale of equity investments	(37)	(254)	(342)
Changes in working capital:
(Increase)/decrease in inventories	(461)	70	(111)
(Increase)/decrease in trade receivables	(287)	(188)	98
Increase in trade payables	11	96	40
Decrease/(increase) in other receivables	74	381	(593)
Contingent consideration paid (see Note 39)	(594)	(358)	(121)
Other non-cash increase in contingent consideration liabilities	961	2,281	1,986
Increase in other payables	1,741	1,989	276
(Decrease)/increase in pension and other provisions	(255)	(621)	100
Share-based incentive plans	333	319	368
Fair value adjustments		(3)
Other	(95)	(21)	(187)
Adjustments reconciling profit after tax to operating cash flows	6,089	7,044	(3,741)
Cash generated from operations	£ 8,258	£ 8,106	£ 4,631

XML

Reconciliation of Net Cash Flow to Movement in Net Debt - Summary of Net Debt (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of net debt [Abstract]
Net debt at beginning of year	£ (13,804)	£ (10,727)	£ (14,377)
(Decrease)/increase in cash and bank overdrafts	(905)	(1,164)	1,503
(Decrease)/increase in liquid investments	(4)		2
Net increase in long-term loans	(2,233)
Net repayment of/(increase in) short-term loans	3,200	(148)	2,412
Net repayment of obligations under finance leases	23	18	25
Exchange adjustments	585	(1,781)	(268)
Other non-cash movements	(40)	(2)	(24)
Movement in net debt	626	(3,077)	3,650
Net debt at end of year	£ (13,178)	£ (13,804)	£ (10,727)

XML

Reconciliation of Net Cash Flow to Movement in Net Debt - Summary of Analysis of Changes in Net Debt (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of debt [Line Items]
Beginning balance	£ (13,804)
Exchange	585	£ (1,781)	£ (268)
Other	(24)
Profit and loss	(16)
Disposals	(6)
Cash flow	87
Ending balance	(13,178)	(13,804)
Liquid Investments [member]
Disclosure of debt [Line Items]
Beginning balance	89
Exchange	(7)
Cash flow	(4)
Ending balance	78	89
Cash and cash equivalents [member]
Disclosure of debt [Line Items]
Beginning balance	4,897
Exchange	(106)
Disposals	(6)
Cash flow	(952)
Ending balance	3,833	4,897
Overdrafts [Member]
Disclosure of debt [Line Items]
Beginning balance	(292)
Exchange	6
Cash flow	53
Ending balance	(233)	(292)
Cash and cash equivalents and overdrafts [member]
Disclosure of debt [Line Items]
Beginning balance	4,605
Exchange	(100)
Disposals	(6)
Cash flow	(899)
Ending balance	3,600	4,605
Commercial paper [member]
Disclosure of debt [Line Items]
Beginning balance	(1,094)
Exchange	37
Cash flow	528
Ending balance	(529)	(1,094)
European and US Medium Term Notes [Member]
Disclosure of debt [Line Items]
Beginning balance	(2,680)
Exchange	121
Reclassification	(2,114)
Cash flow	2,636
Ending balance	(2,037)	(2,680)
Other [member]
Disclosure of debt [Line Items]
Beginning balance	(63)
Exchange	2
Other	(5)
Reclassification	(19)
Cash flow	59
Ending balance	(26)	(63)
Short term debt [member]
Disclosure of debt [Line Items]
Beginning balance	(3,837)
Exchange	160
Other	(5)
Reclassification	(2,133)
Cash flow	3,223
Ending balance	(2,592)	(3,837)
European and US medium term notes non-current [member]
Disclosure of debt [Line Items]
Beginning balance	(14,620)
Exchange	530
Other	4
Profit and loss	(16)
Reclassification	2,114
Cash flow	(2,233)
Ending balance	(14,221)	(14,620)
Other non-current debt [member]
Disclosure of debt [Line Items]
Beginning balance	(41)
Exchange	2
Other	(23)
Reclassification	19
Ending balance	(43)	(41)
Long term debt [member]
Disclosure of debt [Line Items]
Beginning balance	(14,661)
Exchange	532
Other	(19)
Profit and loss	(16)
Reclassification	2,133
Cash flow	(2,233)
Ending balance	(14,264)	£ (14,661)
Long Term Debt Due With In One Year [Member]
Disclosure of debt [Line Items]
Beginning balance	(3,837)
Exchange	160
Other	(5)
Reclassification	(2,133)
Disposals	0
Cash flow	3,223
Ending balance	(2,592)
Long Term Debt Due after 2018 [member]
Disclosure of debt [Line Items]
Beginning balance	(14,661)
Exchange	532
Other	(19)
Profit and loss	(16)
Reclassification	2,133
Disposals	0
Cash flow	(2,233)
Ending balance	(14,264)
Derivative financial instruments [member]
Disclosure of debt [Line Items]
Beginning balance	(38)
Other	37
Profit and loss	5
Disposals	0
Cash flow	(2)
Ending balance	2
Other financing items [member]
Disclosure of debt [Line Items]
Exchange	91
Disposals	0
Cash flow	(91)
Accrued interest [member]
Disclosure of debt [Line Items]
Beginning balance	(158)
Exchange	4
Other	1
Profit and loss	(731)
Reclassification	(100)
Disposals	0
Cash flow	781
Ending balance	(203)
Liabilities arising from financing activities [member]
Disclosure of debt [Line Items]
Beginning balance	(18,694)
Exchange	787
Other	14
Profit and loss	(742)
Reclassification	(100)
Disposals	0
Cash flow	1,678
Ending balance	£ (17,057)

XML

Acquisitions and disposals - 2016 Acquisitions - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£) Acquisitions Acquisition	Dec. 31, 2016 GBP (£)	Dec. 31, 2015 GBP (£)
Disclosure of detailed information about business combination [line items]
Cash investment in associates and joint ventures	£ 15
Goodwill	5,734	£ 5,965	£ 5,162
Cash investment in associates and joint ventures	183	263	£ 207
2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	342
Deferred consideration receivable	86
Cash consideration paid	198
Associates [member]
Disclosure of detailed information about business combination [line items]
Cash consideration paid	£ 198
Number of investment holdings sold	2
2017 acquisition [member]
Disclosure of detailed information about business combination [line items]
Number of acquisitions | Acquisition	0
2016 acquisitions [member]
Disclosure of detailed information about business combination [line items]
Number of acquisitions | Acquisitions	2
2016 acquisitions [member] | 2016 business disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	£ 72
Deferred consideration receivable	£ 43
HIV R&D preclinical and discovery stage portfolio [member]
Disclosure of detailed information about business combination [line items]
Cash consideration		24
Initial estimate of recognised for contingent consideration		40
Intangible assets		57
Goodwill		7
Galvani Bioelectronics Limited [member]
Disclosure of detailed information about business combination [line items]
Intangible assets		45
Cash and cash equivalents		£ 41
Proportion of non-controlling interest		45.00%
Fair value of shareholdings		£ 47
Non controlling interest		£ 39

XML

Acquisitions and Disposals - Summary of Profit on Disposal of Businesses (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015
Net assets sold:
Reclassification of exchange from other comprehensive income	£ 109
2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration including currency forwards and purchase adjustments	342
Net assets sold:
Goodwill	(16)
Intangible assets	(21)
Property, plant and equipment	(18)
Inventory	(11)
Cash	(6)
Other net assets	(5)
Net assets sold	(77)
Transaction costs	(8)
Reclassification of exchange from other comprehensive income	(100)
Profit on disposal	£ 157
Oncology [member]
Disclosure of detailed information about business combination [line items]
Cash consideration including currency forwards and purchase adjustments		£ (10,060)
Net assets sold:
Goodwill		(497)
Intangible assets		(516)
Net assets sold		(1,013)
Loss on currency forwards booked in 2014		299
Disposal costs		(118)
Profit on disposal		9,228
Other business disposal [member]
Disclosure of detailed information about business combination [line items]
Cash consideration including currency forwards and purchase adjustments		(309)
Net assets sold:
Goodwill		(14)
Intangible assets		(107)
Property, plant and equipment		(25)
Inventory		(51)
Cash		(5)
Other net assets		(6)
Net assets sold		(208)
Disposal costs		(21)
Profit on disposal		£ 80

XML

Acquisitions and Disposals - Summary of Disposal of Associates (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015
2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	£ 198
Investment associates and joint ventures [member]
Disclosure of detailed information about business combination [line items]
Cash consideration		£ 571
Net book value of shares		143
Reclassification of exchange from other comprehensive income		30
Transaction costs		7
Profit on disposal		£ 386
Investment associates and joint ventures [member] | 2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	198
Net book value of shares	(92)
Reclassification of exchange from other comprehensive income	(7)
Transaction costs	(5)
Profit on disposal	£ 94

XML

Acquisitions and Disposals - Summary of Investment in Associates and Joint Ventures (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of detailed information about business combination [line items]
Contingent consideration paid	£ 91	£ 73	£ 338
Cash (outflow)/inflow	(1,443)	£ (1,269)	6,037
Cash flows in 2015 [member]
Disclosure of detailed information about business combination [line items]
Cash consideration			7,355
Cash and cash equivalents acquired/(divested)			399
Deferred cash proceeds			(38)
Contingent consideration paid			(338)
Transaction costs and other			(109)
Cash (outflow)/inflow			7,269
2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	198
Transaction costs and other	(2)
Cash (outflow)/inflow	196
Investment associates and joint ventures [member]
Disclosure of detailed information about business combination [line items]
Cash consideration			571
Net book value of shares			(143)
Reclassification of exchange from other comprehensive income			(30)
Transaction fees			(7)
Other items			(5)
Profit on disposal			386
Investment associates and joint ventures [member] | 2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	198
Net book value of shares	92
Reclassification of exchange from other comprehensive income	7
Transaction fees	5
Profit on disposal	94
Business combinations [member] | Cash flows in 2015 [member]
Disclosure of detailed information about business combination [line items]
Cash consideration			(3,585)
Cash and cash equivalents acquired/(divested)			404
Contingent consideration paid			(338)
Transaction costs and other			(22)
Cash (outflow)/inflow			(3,541)
Business combinations [member] | 2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	256
Cash and cash equivalents acquired/(divested)	(6)
Contingent consideration paid	39
Transaction costs and other	(7)
Cash (outflow)/inflow	282
Business disposals [member] | Cash flows in 2015 [member]
Disclosure of detailed information about business combination [line items]
Cash consideration			10,369
Cash and cash equivalents acquired/(divested)			(5)
Deferred cash proceeds			(38)
Transaction costs and other			(80)
Cash (outflow)/inflow			10,246
Associates and JV disposal [member] | Cash flows in 2015 [member]
Disclosure of detailed information about business combination [line items]
Cash consideration			571
Transaction costs and other			(7)
Cash (outflow)/inflow			£ 564
Associates and JV disposal [member] | 2017 disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration	(15)
Cash (outflow)/inflow	£ (15)

XML

Acquisitions and Disposals - Summary of Cash Flows from Business Combinations (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2016 GBP (£)
Business acquisitions [member]
Disclosure of detailed information about business combination [line items]
Cash consideration (paid)/received after purchase adjustments	£ (24)
Cash and cash equivalents acquired	41
Cash inflow	17
Business disposals [member]
Disclosure of detailed information about business combination [line items]
Cash consideration (paid)/received after purchase adjustments	72
Cash inflow	£ 72

XML

Acquisitions and disposals - 2015 Acquisitions - Additional Information (Detail) £ in Millions, $ in Millions	1 Months Ended	10 Months Ended	12 Months Ended
	Mar. 31, 2015 GBP (£)	Dec. 31, 2015 GBP (£)	Dec. 31, 2017 GBP (£)	Dec. 31, 2017 USD ($)	Dec. 31, 2015 GBP (£)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 GBP (£)
Disclosure of detailed information about business combination [line items]
Goodwill		£ 5,162	£ 5,734		£ 5,162		£ 5,965
Cash investment in associates and joint ventures		207	183		207		£ 263
Other business disposal [member]
Disclosure of detailed information about business combination [line items]
Cash consideration, net			309
Oncology product [member]
Disclosure of detailed information about business combination [line items]
Oncology business cash consideration			£ 10,395	$ 16,000
Novartis consumer healthcare and vaccines businesses [member]
Disclosure of detailed information about business combination [line items]
Business acquisition date			Mar. 02, 2015	Mar. 02, 2015
Novartis global vaccines business [member]
Disclosure of detailed information about business combination [line items]
Cash consideration			£ 3,417	$ 5,250
Milestone Payments			1,200	$ 1,800
First milestone payments			£ 300			$ 450
Equity ownership percentage and majority control of joint venture			63.50%	63.50%
Vaccines business acquisition [member]
Disclosure of detailed information about business combination [line items]
Cash consideration			£ 120
Fair value of existing investment			15
Goodwill			22
Intangible assets			124
Other net liabilities			11
Novartis consumer health care [member]
Disclosure of detailed information about business combination [line items]
Transaction costs for acquisition recognized in 2014 and 2015					£ 102
Novartis consumer health care and vaccines business [member]
Disclosure of detailed information about business combination [line items]
Group turnover since date of business acquisition		1,941
Estimated group turn over additional amount of after acquisition		£ 320
Investment associates and joint ventures [member]
Disclosure of detailed information about business combination [line items]
Cash investment in associates and joint ventures			£ 16
Issued share capital percentage	6.20%
issued share capital, cash	£ 571

XML

Acquisitions and Disposals - Summary of Fair Values of the Assets Acquired in Business Combinations, Including Goodwill (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Net assets acquired:
Goodwill	£ 5,162	£ 5,734	£ 5,965
Novartis consumer health care business[member]
Net assets acquired:
Intangible assets	6,003
Property, plant and equipment	249
Inventory	257
Trade and other receivables	400
Other assets including cash and cash equivalents	304
Trade and other payables	(402)
Deferred tax liabilities	(1,154)
Other liabilities	(165)
Assets liabilities excluding goodwill	5,492
Non-controllinginterest	(2,150)
Goodwill	774
Net assets liabilities including goodwill	4,116
Novartis consumer health care business[member] | GSK consumer health care holdings [member]
Net assets acquired:
Consideration settled by shares in GSK Consumer Healthcare Holdings	4,116
Total consideration	4,116
Novartis vaccines business [member]
Net assets acquired:
Intangible assets	2,680
Property, plant and equipment	434
Inventory	347
Trade and other receivables	162
Other assets including cash and cash equivalents	283
Trade and other payables	(107)
Deferred tax liabilities	(78)
Other liabilities	(299)
Assets liabilities excluding goodwill	3,422
Non-controllinginterest	(19)
Goodwill	576
Net assets liabilities including goodwill	3,979
Novartis vaccines business [member] | GSK consumer health care holdings [member]
Net assets acquired:
Cash consideration paid after purchase adjustments	3,461
Contingent consideration	594
Deferred tax on contingent consideration	(52)
Loss on settlement of pre-existing relationships	(24)
Total consideration	3,979
Other [member]
Net assets acquired:
Intangible assets	124
Property, plant and equipment	1
Trade and other receivables	2
Other assets including cash and cash equivalents	19
Trade and other payables	(3)
Deferred tax liabilities	(26)
Assets liabilities excluding goodwill	117
Goodwill	22
Net assets liabilities including goodwill	139
Other [member] | GSK consumer health care holdings [member]
Net assets acquired:
Cash consideration paid after purchase adjustments	124
Fair value of equity investment disposal	15
Total consideration	£ 139

XML

Contingent consideration liabilities - Summary of Fair Value Contingent Consideration (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of fair value of contingent consideration [Line Items]
At 1 January 2015	£ 5,896	£ 3,855	£ 1,724
Additions through business combinations		194	594
Remeasurement through income statement	961	2,281	1,986
Cash payments: operating cash flows	(594)	(358)	(121)
Cash payments: investing activities	(91)	(73)	(338)
Other movements		(3)	10
At 31 December 2015	6,172	5,896	3,855
Shionogi ViiV healthcare joint venture [member]
Disclosure of fair value of contingent consideration [Line Items]
At 1 January 2015	5,304	3,409	1,684
Additions through business combinations		154
Remeasurement through income statement	909	2,162	1,874
Cash payments: operating cash flows	(587)	(351)	(121)
Cash payments: investing activities	(84)	(66)	(38)
Other movements		(4)	10
At 31 December 2015	5,542	5,304	3,409
Novartis [member]
Disclosure of fair value of contingent consideration [Line Items]
At 1 January 2015	545	405
Additions through business combinations			594
Remeasurement through income statement	53	152	111
Cash payments: operating cash flows	(7)	(5)
Cash payments: investing activities	(7)	(7)	(300)
At 31 December 2015	584	545	405
Other [member]
Disclosure of fair value of contingent consideration [Line Items]
At 1 January 2015	47	41	40
Additions through business combinations		40
Remeasurement through income statement	(1)	(33)	1
Cash payments: operating cash flows		(2)
Other movements		1
At 31 December 2015	£ 46	£ 47	£ 41

XML

Contingent Consideration Liabilities - Additional Information (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of fair value of contingent consideration [Line Items]
Contingent consideration payable	£ 1,076	£ 561
Shionogi ViiV healthcare joint venture [member]
Disclosure of fair value of contingent consideration [Line Items]
Contingent consideration liability discount percentage	8.50%
Novartis [member] | Bottom of range [member]
Disclosure of fair value of contingent consideration [Line Items]
Contingent consideration liability discount percentage	8.00%
Novartis [member] | Top of range [member]
Disclosure of fair value of contingent consideration [Line Items]
Contingent consideration liability discount percentage	9.00%

XML

Contingent consideration liabilities - Summary of Possible Changes in key Inputs to Valuation of Contingent Consideration Liabilities (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£)
Shionogi ViiV healthcare joint venture [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10% increase in sales forecasts	£ 535
10% decrease in sales forecasts	(535)
1% increase in discount rate	(228)
1% decrease in discount rate	245
Shionogi ViiV healthcare joint venture [member] | 10 cent appreciation of the US Dollar [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent appreciation of US Dollar	329
Shionogi ViiV healthcare joint venture [member] | 10 cent depreciation of US Dollar [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent depreciation of US Dollar	(284)
Shionogi ViiV healthcare joint venture [member] | 10 cent appreciation of the Euro [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent appreciation of Euro	95
Shionogi ViiV healthcare joint venture [member] | 10 cent depreciation of Euro [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent depreciation of Euro	(80)
Novartis vaccines [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10% increase in sales forecasts	56
10% decrease in sales forecasts	(55)
1% increase in discount rate	(18)
1% decrease in discount rate	20
5% increase in probability of milestone success	6
5% decrease in probability of milestone success	(6)
Novartis vaccines [member] | 10 cent appreciation of the US Dollar [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent appreciation of US Dollar	17
Novartis vaccines [member] | 10 cent depreciation of US Dollar [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent depreciation of US Dollar	(15)
Novartis vaccines [member] | 10 cent appreciation of the Euro [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent appreciation of Euro	25
Novartis vaccines [member] | 10 cent depreciation of Euro [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
10 cent depreciation of Euro	£ (21)

XML

Contingent consideration liabilities - Summary of Possible Changes in key Inputs to Valuation of Contingent Consideration Liabilities (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017
Shionogi ViiV healthcare joint venture [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
Increase in sales forecasts	10.00%
Decrease in sales forecasts	10.00%
increase in discount rate	1.00%
Decrease in discount rate	1.00%
Novartis vaccines [member]
Disclosure of valuation techniques and key model inputs used to measure contingent consideration [Line Items]
Increase in sales forecasts	10.00%
Decrease in sales forecasts	10.00%
increase in discount rate	1.00%
Decrease in discount rate	1.00%
Increase in probability of milestone success	5.00%
Decrease in probability of milestone success	5.00%

XML

Non-controlling interests - Summarised Financial Information of ViiV Healthcare Group and GSK Consumer Healthcare Joint Venture (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of noncontrolling interests [Line Items]
Total comprehensive expense for the year attributable to non-controllinginterests	£ 2,882	£ 2,024	£ 7,885
Non-controlling interests in the Consolidated balance sheet	3,557	3,839
Turnover	30,186	27,889	23,923
Profit/(loss) after taxation	637	150	(50)
Other comprehensive income	713	962	(487)
Total comprehensive income	488	753	(42)
Non-current assets	40,474	42,370
Current assets	15,907	16,711
Total assets	56,381	59,081
Current liabilities	(26,569)	(19,001)
Non-current liabilities	(26,323)	(35,117)
Total liabilities	(52,892)	(54,118)
Net assets	3,489	4,963
Net cash inflow from operating activities	6,918	6,497	2,569
Net cash inflow/(outflow) from investing activities	(1,443)	(1,269)	6,037
Net cash outflow from financing activities	(6,380)	(6,392)	(7,103)
ViiV healthcare [member]
Disclosure of noncontrolling interests [Line Items]
Total comprehensive expense for the year attributable to non-controllinginterests	187	(83)	(143)
Dividends paid to non-controlling interests	316	152	163
Non-controlling interests in the Consolidated balance sheet	(476)	(353)
Turnover	4,269	3,527	2,330
Profit/(loss) after taxation	825	(1,249)	(1,426)
Other comprehensive income	20	36	7
Total comprehensive income	845	(1,213)	(1,419)
Non-current assets	2,736	3,064
Current assets	2,533	2,357
Total assets	5,269	5,421
Current liabilities	(2,409)	(1,977)
Non-current liabilities	(8,011)	(7,983)
Total liabilities	(10,420)	(9,960)
Net assets	(5,151)	(4,539)
Net cash inflow from operating activities	2,132	1,750	1,097
Net cash inflow/(outflow) from investing activities	(207)	(326)	(63)
Net cash outflow from financing activities	(1,820)	(1,023)	(814)
Decrease in cash and bank overdrafts in the year	105	401	220
Consumer health care joint venture [member]
Disclosure of noncontrolling interests [Line Items]
Total comprehensive expense for the year attributable to non-controllinginterests	296	730	14
Dividends paid to non-controlling interests	420	346
Non-controlling interests in the Consolidated balance sheet	3,631	3,755
Turnover	7,003	6,530	4,627
Profit/(loss) after taxation	1,211	660	(39)
Other comprehensive income	(387)	1,640	72
Total comprehensive income	824	2,300	33
Non-current assets	12,771	13,315
Current assets	3,282	3,996
Total assets	16,053	17,311
Current liabilities	(2,675)	(3,060)
Non-current liabilities	(1,537)	(2,062)
Total liabilities	(4,212)	(5,122)
Net assets	11,841	12,189
Net cash inflow from operating activities	883	1,496	277
Net cash inflow/(outflow) from investing activities	270	(537)	(691)
Net cash outflow from financing activities	(1,194)	(980)	(42)
Decrease in cash and bank overdrafts in the year	£ (41)	£ (21)	£ (456)

XML

Non-controlling interests - Additional Information (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of noncontrolling interests [Line Items]
Profit after taxation	£ 637	£ 150	£ (50)
ViiV healthcare [member]
Disclosure of noncontrolling interests [Line Items]
Profit after taxation	825	(1,249)	(1,426)
Shionogi ViiV healthcare joint venture [member]
Disclosure of noncontrolling interests [Line Items]
Remeasurement of contingent consideration payable for acquisition	£ 909	£ 2,186	£ 1,874

XML

Non-controlling interests - Schedule of Amount Attributable to VIIV Healthcare Group Included in GSK's Consolidated Statement of Comprehensive Income, Consolidated Statement of Changes in Equity and Consolidated Balance Sheet (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of noncontrolling interests [Line Items]
Total comprehensive income for the year attributable to non-controllinginterests	£ 2,882	£ 2,024	£ 7,885
Non-controlling interests in the Consolidated balance sheet	3,557	3,839
Consumer health care joint venture [member]
Disclosure of noncontrolling interests [Line Items]
Total comprehensive income for the year attributable to non-controllinginterests	296	730	£ 14
Dividends paid to non-controlling interests	420	346
Non-controlling interests in the Consolidated balance sheet	£ 3,631	£ 3,755

XML

Commitments - Schedule of Contractual Obligations and Commitments (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Contractual Obligations And Commitments [Abstract]
Intangible assets	£ 5,254	£ 7,199
Property, plant and equipment	584	496
Investments	107	166
Purchase commitments	346	52
Pensions	738	874
Other commitments	38	143
Interest on loans	8,510	9,410
Finance lease charges	12	3
Total contractual obligations and commitments	£ 15,589	£ 18,343

XML

Commitments - Additional Information (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of Commitments [Abstract]
Payment due, 2018	£ 123,000,000
Payment due, 2019	123,000,000
Payment due, 2020	123,000,000
Payment due, 2021	123,000,000
Payment due, 2022	123,000,000
Payment due, 2023	123,000,000
Ongoing annual funding requirement	130,000,000
Commitments under non-cancellable operating leases	£ 117,000,000	£ 186,000,000

XML

Commitments - Summary of Commitments Under Non-Cancellable Operating Leases (Detail) - GBP (£)	Dec. 31, 2017	Dec. 31, 2016
Disclosure of operating lease by lessee [Line Items]
Total commitments under non-cancellable operating leases	£ 1,045,000,000	£ 840,000,000
Not later than one year [member]
Disclosure of operating lease by lessee [Line Items]
Total commitments under non-cancellable operating leases	186,000,000	153,000,000
Between one and two years [member]
Disclosure of operating lease by lessee [Line Items]
Total commitments under non-cancellable operating leases	149,000,000	129,000,000
Between two and three years [member]
Disclosure of operating lease by lessee [Line Items]
Total commitments under non-cancellable operating leases	122,000,000	94,000,000
Between Three and Four Years [Member]
Disclosure of operating lease by lessee [Line Items]
Total commitments under non-cancellable operating leases	107,000,000	74,000,000
Between four and five years [member]
Disclosure of operating lease by lessee [Line Items]
Total commitments under non-cancellable operating leases	94,000,000	66,000,000
Later than five years [member]
Disclosure of operating lease by lessee [Line Items]
Total commitments under non-cancellable operating leases	£ 387,000,000	£ 324,000,000

XML

Financial instruments and related disclosures - Additional Information (Detail) shares in Millions, $ in Billions	12 Months Ended
	Dec. 31, 2017 GBP (£) shares	Dec. 12, 2017 GBP (£)	Dec. 31, 2016 GBP (£) shares	Dec. 31, 2015 GBP (£)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2014 GBP (£)
Disclosure of detailed information about financial instruments [line items]
Amount of borrowings repayable within one year	£ 13,178,000,000		£ 13,804,000,000	£ 10,727,000,000			£ 14,377,000,000
Non-controlling interests	3,557,000,000		3,839,000,000
Total capital	16,700,000,000
Short-term finance through issuance of commercial paper	529,000,000		1,094,000,000
Maximum exposure to credit risk	9,988,000,000		£ 11,002,000,000
Bank balances and deposits held with counter parties | shares			2,583
Group trade receivables due from three largest US wholesalers	4,672,000,000		£ 4,615,000,000
Carrying value of shares held by trust under employee share ownership plan	400,000,000		286,000,000
Fair value of shares held by trust under employee share ownership plan	882,000,000		667,000,000
Treasury shares at cost	5,800,000,000		6,451,000,000
Remeasurement through income statement	(961,000,000)		(2,281,000,000)	(1,986,000,000)
Net gains recognised in other comprehensive income	22,000,000		29,000,000
Contingent consideration liabilities	6,172,000,000		5,896,000,000	£ 3,855,000,000			£ 1,724,000,000
Derivative assets			156,000,000
Increase in anticipated contractual cash flows for repayment of debt and debt interest		£ 2,600,000,000
Bonds In A Designated Hedging Relationship [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases	4,315,000,000		3,189,000,000
Foreign Exchange Contracts [member]
Disclosure of detailed information about financial instruments [line items]
Net asset fair value classified as held for trading under IAS 39	15,000,000		34,000,000
Asset classified as held for trading under IAS 39	62,000,000		133,000,000
Liability classified as held for trading under IAS 39	47,000,000		99,000,000
Shionogi ViiV healthcare joint venture [member]
Disclosure of detailed information about financial instruments [line items]
Remeasurement through income statement	909,000,000		2,162,000,000
Novartis [member]
Disclosure of detailed information about financial instruments [line items]
Remeasurement through income statement	53,000,000		152,000,000
Level 3 [member]
Disclosure of detailed information about financial instruments [line items]
Net losses recognised in the income statement	970,000,000		2,283,000,000
Level 3 [member] | Equity investments [member]
Disclosure of detailed information about financial instruments [line items]
Net gains (losses) on equity investments held	(6,000,000)		21,000,000
Level 3 [member] | Shionogi ViiV healthcare joint venture [member]
Disclosure of detailed information about financial instruments [line items]
Contingent consideration liabilities	5,542,000,000		5,304,000,000
Level 3 [member] | Novartis [member]
Disclosure of detailed information about financial instruments [line items]
Contingent consideration liabilities	584,000,000		545,000,000
Not later than one year [member]
Disclosure of detailed information about financial instruments [line items]
Derivative assets	68,000,000		156,000,000
Increase in contractual cash flows for non-derivative financial liabilities	8,400,000,000
Between one and two years [member]
Disclosure of detailed information about financial instruments [line items]
Decrease in contractual cash flows for non-derivative financial liabilities	8,900,000,000
Credit risk [member]
Disclosure of detailed information about financial instruments [line items]
Amount of cash held at unrated counter parties	45,000,000
Cash in transit	£ 32,000,000
Bank balances and deposits held with counter parties | shares	1,715
Cash held by subsidiary	£ 1,700,000,000
Derivative assets	£ 68,000,000
Credit risk [member] | Non USA [member]
Disclosure of detailed information about financial instruments [line items]
Number of major customers accounting for more than 5% of trade receivables	0
Credit risk [member] | Nigeria [member]
Disclosure of detailed information about financial instruments [line items]
Concentration of credit risk	£ 7,000,000
Credit risk [member] | Austria [member]
Disclosure of detailed information about financial instruments [line items]
Concentration of credit risk	2,000,000
Credit risk [member] | HDFC bank [member]
Disclosure of detailed information about financial instruments [line items]
Balances or deposits with banks	17,000,000
Credit risk [member] | State Bank of India [member]
Disclosure of detailed information about financial instruments [line items]
Balances or deposits with banks	10,000,000
Credit risk [member] | Not later than three months [member]
Disclosure of detailed information about financial instruments [line items]
Cash reserves	2,500,000,000
Liquidity risk [member]
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents and liquid investments	3,900,000,000
Cash and cash equivalents and liquid investments held centrally	2,500,000,000
Short-term finance through issuance of commercial paper	£ 500,000,000				$ 0.7	$ 1.4
Description of contractual committed facilities	The five-year committed facilities were agreed in September 2015 and were extended by one year to 2021 in September 2016. The 364 day committed facilities were agreed in August 2017. These facilities were undrawn at 31 December 2017. GSK considers this level of committed facilities to be adequate, given current liquidity requirements.
Amount held at European medium term note programme	£ 15,000,000,000
Notes issued at European medium term note programme	9,000,000,000
Notes issued under us shelf registration	£ 7,200,000,000				9.7
Description of maturity date of borrowings	GSK's borrowings mature at dates between 2018 and 2045.
Liquidity risk [member] | Not later than one year [member]
Disclosure of detailed information about financial instruments [line items]
Amount of borrowings repayable within one year	£ 2,800,000,000
Committed facilities during the period	1,900,000,000				2.5
Liquidity risk [member] | Later than one year and not later than five years [member]
Disclosure of detailed information about financial instruments [line items]
Committed facilities during the period	1,900,000,000
1% (100 basis points) increase in sterling interest rates [member]
Disclosure of detailed information about financial instruments [line items]
Impact on income through interest rate movements	24,000,000		3,000,000
External credit grades [member] | Credit risk [member]
Disclosure of detailed information about financial instruments [line items]
Concentration of credit risk	£ 500,000,000		£ 900,000,000
BBB/Baa [member]
Disclosure of detailed information about financial instruments [line items]
Bank balances and deposits held with counter parties | shares			388
BBB/Baa [member] | Credit risk [member]
Disclosure of detailed information about financial instruments [line items]
Bank balances and deposits held with counter parties | shares	80
BBB -/ Baa3 Rated [member] | Credit risk [member]
Disclosure of detailed information about financial instruments [line items]
Bank balances and deposits held with counter parties | shares	27
Floating interest rate [member]
Disclosure of detailed information about financial instruments [line items]
Percentage of increase in interest rate	1.00%
Floating interest rate [member] | 1% (100 basis points) increase in sterling interest rates [member]
Disclosure of detailed information about financial instruments [line items]
Impact on income through interest rate movements	£ 5,000,000		£ 3,000,000
Top of range [member] | Credit risk [member] | Non USA [member]
Disclosure of detailed information about financial instruments [line items]
Maximum percentage of trade receivables balance held by major customer account	5.00%
Pharmaceuticals and Vaccines [member] | Credit risk [member] | USA [member]
Disclosure of detailed information about financial instruments [line items]
Percentage of sales to three largest wholesalers	83.00%
Group trade receivables due from three largest US wholesalers	£ 1,265,000,000		£ 1,323,000,000
US commercial paper program [member] | Liquidity risk [member]
Disclosure of detailed information about financial instruments [line items]
Short-term finance at commercial paper programme	£ 7,400,000,000				$ 10.0
ViiV healthcare [member] | Credit risk [member]
Disclosure of detailed information about financial instruments [line items]
Percentage of ownership interest in subsidiary	78.30%

XML

Financial Instruments and Related Disclosures - Summary of External Credit Exposure (Detail) - GBP (£) £ in Millions, shares in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of external credit grades [line items]
Bank balances and deposits		2,583
US Treasury and Treasury repo only money market funds		£ 2,248
Liquidity funds		66
Government securities		89
3rd party financial derivatives		156
Total		5,142
Credit risk [member]
Disclosure of external credit grades [line items]
Bank balances and deposits	1,715
US Treasury and Treasury repo only money market funds	£ 1,715
Liquidity funds	403
Government securities	78
3rd party financial derivatives	68
Total	3,979
AAA/Aaa [member]
Disclosure of external credit grades [line items]
US Treasury and Treasury repo only money market funds		2,248
Liquidity funds		66
Total		£ 2,314
AAA/Aaa [member] | Credit risk [member]
Disclosure of external credit grades [line items]
US Treasury and Treasury repo only money market funds	1,715
Liquidity funds	403
Total	£ 2,118
AA/Aa [member]
Disclosure of external credit grades [line items]
Bank balances and deposits		542
Government securities		£ 85
3rd party financial derivatives		70
Total		£ 697
AA/Aa [member] | Credit risk [member]
Disclosure of external credit grades [line items]
Bank balances and deposits	423
Government securities	£ 77
3rd party financial derivatives	26
Total	£ 526
A/A [member]
Disclosure of external credit grades [line items]
Bank balances and deposits		1,560
3rd party financial derivatives		£ 86
Total		£ 1,646
A/A [member] | Credit risk [member]
Disclosure of external credit grades [line items]
Bank balances and deposits	1,167
3rd party financial derivatives	£ 42
Total	£ 1,209
BBB/Baa [member]
Disclosure of external credit grades [line items]
Bank balances and deposits		388
Government securities		£ 4
Total		£ 392
BBB/Baa [member] | Credit risk [member]
Disclosure of external credit grades [line items]
Bank balances and deposits	80
Government securities	£ 1
Total	£ 81
BB+/Ba1 and Below/Unrated [member]
Disclosure of external credit grades [line items]
Bank balances and deposits		93
Total		£ 93
BB+/Ba1 and Below/Unrated [member] | Credit risk [member]
Disclosure of external credit grades [line items]
Bank balances and deposits	45
Total	£ 45

XML

Financial Instruments and Related Disclosures - Summary of Financial Assets and Liabilities (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Disclosure of detailed information about financial instruments [line items]
Total financial assets	£ 10,906	£ 11,987
Cash and cash equivalents	3,833	4,897	£ 5,830
Total borrowings	(13,178)	(13,804)	£ (10,727)	£ (14,377)
Trade and other payables, Other provisions and certain Other non-current liabilities in scope of IAS 39	(20,325)	(18,713)
Total financial liabilities	(43,660)	(43,593)
Net financial assets and financial liabilities	(32,754)	(31,606)
Total financial assets fair value	10,906	11,987
Total financial liabilities fair value	(46,599)	(46,624)
Net financial assets and financial liabilities	(35,693)	(34,637)
Bonds In A Designated Hedging Relationship [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases:	(4,315)	(3,189)
Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of detailed information about financial instruments [line items]
Total financial assets	7,413	7,225
Financial Liabilities at Amortised Cost, Category [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases:	(17,023)	(18,726)
Obligations under finance leases	(66)	(64)
Total borrowings	(17,089)	(18,790)
Borrowings excluding obligations under finance leases	(19,962)	(21,757)
Obligations under finance leases	(66)	(64)
Total borrowings	(20,028)	(21,821)
Trade and other payables, Other provisions and certain Other non-current liabilities in scope of IAS 39	(20,325)	(18,713)
Financial Liabilities at Amortised Cost, Category [member] | Bonds In A Designated Hedging Relationship [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases:	(4,315)	(3,189)
Borrowings excluding obligations under finance leases	(4,405)	(3,335)
Financial Liabilities at Amortised Cost, Category [member] | Other Bonds [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases:	(11,894)	(14,111)
Borrowings excluding obligations under finance leases	(14,743)	(16,996)
Financial Liabilities at Amortised Cost, Category [member] | Bank Loans and Overdrafts [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases:	(236)	(332)
Borrowings excluding obligations under finance leases	(236)	(332)
Financial Liabilities at Amortised Cost, Category [member] | Commercial paper [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases:	(529)	(1,094)
Borrowings excluding obligations under finance leases	(529)	(1,094)
Financial Liabilities at Amortised Cost, Category [member] | Other Borrowing [member]
Disclosure of detailed information about financial instruments [line items]
Borrowings excluding obligations under finance leases:	(49)
Borrowings excluding obligations under finance leases	(49)
Financial Liabilities at Fair Value Through Profit or Loss, Category [member] | Contingent Consideration Liabilities [member]
Disclosure of detailed information about financial instruments [line items]
Total financial liabilities	(6,172)	(5,896)
Total financial liabilities fair value	(6,172)	(5,896)
Financial Liabilities at Fair Value Through Profit or Loss, Category [member] | Derivatives Financial Liabilities Designated At Fair Value Through Profit Or Loss [member]
Disclosure of detailed information about financial instruments [line items]
Total financial liabilities	(26)	(92)
Total financial liabilities fair value	(26)	(92)
Financial Liabilities at Fair Value Through Profit or Loss, Category [member] | Derivatives financial liabilities classified as held for trading under IAS39 [member]
Disclosure of detailed information about financial instruments [line items]
Total financial liabilities	(48)	(102)
Total financial liabilities fair value	(48)	(102)
Financial Assets Available-for-sale, Category [member] | Government bonds [member]
Disclosure of detailed information about financial instruments [line items]
Total financial assets	78	89
Total financial assets fair value	78	89
Financial Assets Available-for-sale, Category [member] | Other Investments [member]
Disclosure of detailed information about financial instruments [line items]
Total financial assets	918	985
Total financial assets fair value	918	985
Loans and Receivables, Category [member]
Disclosure of detailed information about financial instruments [line items]
Cash and cash equivalents	3,833	4,897
Total financial assets fair value	5,495	5,499
Loans and Receivables, Category [member] | Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of detailed information about financial instruments [line items]
Total financial assets	5,495	5,499
Total financial assets fair value	3,833	4,897
Financial Assets at Fair Value Through Profit or Loss, Category [member] | Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of detailed information about financial instruments [line items]
Total financial assets	506	361
Total financial assets fair value	506	361
Financial Assets at Fair Value Through Profit or Loss, Category [member] | Derivatives Financial Assets Designated At Fair Value Through Profit Or Loss [member]
Disclosure of detailed information about financial instruments [line items]
Total financial assets	5	23
Total financial assets fair value	5	23
Financial Assets at Fair Value Through Profit or Loss, Category [member] | Derivatives Financial Assets Classified As Held For Trading Under IAS39 [member]
Disclosure of detailed information about financial instruments [line items]
Total financial assets	71	133
Total financial assets fair value	£ 71	£ 133

XML

Financial Instruments and Related Disclosures - Summary of Fair Value of Financial Instruments (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	£ 10,906	£ 11,987
Financial liabilities at fair value	(46,599)	(46,624)
At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	1,578	1,591
Financial liabilities at fair value	(6,246)	(6,090)
Financial Liabilities at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial liabilities at fair value	(26)	(92)
Financial Liabilities at Fair Value Through Profit or Loss That Meet Definition of Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial liabilities at fair value	(48)	(102)
Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		23
Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		133
Liquid Investments [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	78	89
Other Investments [member] | Financial Assets Available-for-sale, Category [member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	918	985
Other Investments [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	918	985
Other non-current assets [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		6
Other non-current assets [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	38
Other non-current assets [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	426
Other non-current assets [member] | Financial Assets at Fair Value Through Profit or Loss, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		355
Trade and Other Receivable [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	42
Derivatives Financial Assets Designated At Fair Value Through Profit Or Loss [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	5
Derivatives Financial Assets Designated At Fair Value Through Profit Or Loss [member] | Financial Assets at Fair Value Through Profit or Loss, Category [member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	5	23
Derivatives assets held for trading [Member] | Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	71
Contingent Consideration Liabilities [member] | Financial Liabilities at Fair Value Through Profit or Loss, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial liabilities at fair value	(6,172)	(5,896)
Level 1 of fair value hierarchy [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	612	664
Level 1 of fair value hierarchy [member] | Liquid Investments [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	77	84
Level 1 of fair value hierarchy [member] | Other Investments [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	535	580
Level 2 of fair value hierarchy [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	450	516
Financial liabilities at fair value	(73)	(193)
Level 2 of fair value hierarchy [member] | Financial Liabilities at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial liabilities at fair value	(26)	(92)
Level 2 of fair value hierarchy [member] | Financial Liabilities at Fair Value Through Profit or Loss That Meet Definition of Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial liabilities at fair value	(47)	(101)
Level 2 of fair value hierarchy [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		23
Level 2 of fair value hierarchy [member] | Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		133
Level 2 of fair value hierarchy [member] | Liquid Investments [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	1	5
Level 2 of fair value hierarchy [member] | Other non-current assets [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	382
Level 2 of fair value hierarchy [member] | Other non-current assets [member] | Financial Assets at Fair Value Through Profit or Loss, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		355
Level 2 of fair value hierarchy [member] | Derivatives Financial Assets Designated At Fair Value Through Profit Or Loss [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	5
Level 2 of fair value hierarchy [member] | Derivatives assets held for trading [Member] | Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	62
Level 3 [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	516	411
Financial liabilities at fair value	(6,173)	(5,897)
Level 3 [member] | Financial Liabilities at Fair Value Through Profit or Loss That Meet Definition of Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial liabilities at fair value	(1)	(1)
Level 3 [member] | Other Investments [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	383	405
Level 3 [member] | Other non-current assets [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value		6
Level 3 [member] | Other non-current assets [member] | Financial Assets Available-for-sale, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	38
Level 3 [member] | Other non-current assets [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	44
Level 3 [member] | Trade and Other Receivable [member] | Financial Assets at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	42
Level 3 [member] | Derivatives assets held for trading [Member] | Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial assets at fair value	9
Level 3 [member] | Contingent Consideration Liabilities [member] | Financial Liabilities at Fair Value Through Profit or Loss, Category [member] | At Fair Value [Member]
Disclosure Of Financial Assets And Liabilities [Line Items]
Financial liabilities at fair value	£ (6,172)	£ (5,896)

XML

Financial Instruments and Related Disclosures - Summary of Movement in Financial Instruments Measured Using Level 3 Valuation Method (Detail) - Level 3 [member] - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of fair value measurement of assets and liabilities [Line Items]
Beginning balance	£ (5,486)	£ (3,582)
Net losses recognised in the income statement	(970)	(2,283)
Net gains recognised in other comprehensive income	22	29
Contingent consideration for businesses divested/acquired during the year	80	(194)
Payment of contingent consideration liabilities	685	431
Additions	117	81
Disposals	(52)	(15)
Transfers from Level 3	(24)	(11)
Exchange	(29)	58
Ending balance	£ (5,657)	£ (5,486)

XML

Financial instruments and related disclosures - Summary of Financial Assets and Non Financial Assets (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of financial assets and non financial assets [Line Items]
Trade and other receivables (Note 24)	£ 6,000	£ 6,026
Other non-current assets (Note 22)	1,413	1,199
Financial assets	10,906	11,987
Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of financial assets and non financial assets [Line Items]
Trade and other receivables (Note 24)	6,000	6,026
Other non-current assets (Note 22)	1,413	1,199
Financial assets	7,413	7,225
Financial Assets at Fair Value Through Profit or Loss, Category [member] | Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of financial assets and non financial assets [Line Items]
Trade and other receivables (Note 24)	42
Other non-current assets (Note 22)	464	361
Financial assets	506	361
Loans and Receivables, Category [member] | Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of financial assets and non financial assets [Line Items]
Trade and other receivables (Note 24)	5,148	5,135
Other non-current assets (Note 22)	347	364
Financial assets	5,495	5,499
Financial Instruments [member] | Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of financial assets and non financial assets [Line Items]
Trade and other receivables (Note 24)	5,190	5,135
Other non-current assets (Note 22)	811	725
Financial assets	6,001	5,860
Non Financial Instruments [member] | Trade and Other Receivables and Certain Other Non-current Assets in Scope of IAS 39 [member]
Disclosure of financial assets and non financial assets [Line Items]
Trade and other receivables (Note 24)	810	891
Other non-current assets (Note 22)	602	474
Financial assets	£ 1,412	£ 1,365

XML

Financial instruments and related disclosures - Schedule of Ageing of Financial Assets Which Are Past Due and For Which No Provision for Bad or Doubtful Debts Has Been Made (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of financial assets that are past due but not impaired [line items]
Financial Assets	£ 10,906	£ 11,987
Financial Assets Past Due and No Provision for Bad and Doubtful Debt [member]
Disclosure of financial assets that are past due but not impaired [line items]
Financial Assets	411	521
Financial Assets Past Due and No Provision for Bad and Doubtful Debt [member] | Past Due by 1-30 Days [member]
Disclosure of financial assets that are past due but not impaired [line items]
Financial Assets	142	137
Financial Assets Past Due and No Provision for Bad and Doubtful Debt [member] | Past Due by 31-90 Days [member]
Disclosure of financial assets that are past due but not impaired [line items]
Financial Assets	70	178
Financial Assets Past Due and No Provision for Bad and Doubtful Debt [member] | Past Due by 91-180 Days [member]
Disclosure of financial assets that are past due but not impaired [line items]
Financial Assets	64	55
Financial Assets Past Due and No Provision for Bad and Doubtful Debt [member] | Past Due by 181-365 Days [member]
Disclosure of financial assets that are past due but not impaired [line items]
Financial Assets	27	53
Financial Assets Past Due and No Provision for Bad and Doubtful Debt [member] | Past Due by More Than 365 Days [member]
Disclosure of financial assets that are past due but not impaired [line items]
Financial Assets	£ 108	£ 98

XML

Financial instruments and related disclosures - Reconciliation of financial instruments within Trade and other payables, Other provisions, Other non-current liabilities and Contingent consideration liabilities (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of financial liabilities [line items]
Other provisions (Note 29)	£ (1,265)	£ (1,500)
Other non-currentliabilities (Note 30)	(981)	(8,445)
Financial liabilities	(43,660)	(43,593)
Trade and Other Payables, Other Provisions and Certain Other Non-Current Liabilities in Scope of IAS 39 [member]
Disclosure of financial liabilities [line items]
Trade and other payables (Note 27)	(20,970)	(11,964)
Other provisions (Note 29)	(1,265)	(1,500)
Other non-currentliabilities (Note 30)	(981)	(8,445)
Contingent consideration liabilities (Note 39)	(6,172)	(5,896)
Financial liabilities	(29,388)	(27,805)
Financial Liabilities at Fair Value Through Profit or Loss, Category [member] | Trade and Other Payables, Other Provisions and Certain Other Non-Current Liabilities in Scope of IAS 39 [member]
Disclosure of financial liabilities [line items]
Contingent consideration liabilities (Note 39)	(6,172)	(5,896)
Financial liabilities	(6,172)	(5,896)
Other Liabilities [member] | Trade and Other Payables, Other Provisions and Certain Other Non-Current Liabilities in Scope of IAS 39 [member]
Disclosure of financial liabilities [line items]
Trade and other payables (Note 27)	(20,129)	(11,041)
Other provisions (Note 29)	(117)	(113)
Other non-currentliabilities (Note 30)	(79)	(7,559)
Financial liabilities	(20,325)	(18,713)
Financial Instruments [member] | Trade and Other Payables, Other Provisions and Certain Other Non-Current Liabilities in Scope of IAS 39 [member]
Disclosure of financial liabilities [line items]
Trade and other payables (Note 27)	(20,129)	(11,041)
Other provisions (Note 29)	(117)	(113)
Other non-currentliabilities (Note 30)	(79)	(7,559)
Contingent consideration liabilities (Note 39)	(6,172)	(5,896)
Financial liabilities	(26,497)	(24,609)
Non Financial Instruments [member] | Trade and Other Payables, Other Provisions and Certain Other Non-Current Liabilities in Scope of IAS 39 [member]
Disclosure of financial liabilities [line items]
Trade and other payables (Note 27)	(841)	(923)
Other provisions (Note 29)	(1,148)	(1,387)
Other non-currentliabilities (Note 30)	(902)	(886)
Financial liabilities	£ (2,891)	£ (3,196)

XML

Financial instruments and related disclosures - Fair Values of Derivatives Held (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of detailed information about hedging instruments [line items]
Fair value of Assets	£ 76	£ 156
Fair value of Liabilities	(74)	(194)
Financial Assets at Fair Value Through Profit or Loss, Mandatory Measured at Fair Value, Category [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Assets	5	23
Financial Assets at Fair Value Through Profit or Loss, Mandatory Measured at Fair Value, Category [member] | Net Investment Hedges [member] | Foreign Exchange Contracts [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Assets	5	18
Financial Assets at Fair Value Through Profit or Loss, Mandatory Measured at Fair Value, Category [member] | Cash Flow Hedges [member] | Foreign Exchange Contracts [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Assets		5
Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Assets	71	133
Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member] | Foreign Exchange Contracts [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Assets	62	133
Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member] | Embedded and Other Derivatives [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Assets	9
Financial Liabilities at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Liabilities	(26)	(92)
Financial Liabilities at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | Net Investment Hedges [member] | Foreign Exchange Contracts [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Liabilities	(25)	(92)
Financial Liabilities at Fair Value Through Profit or Loss, Designated Upon Initial Recognition or Subsequently, Category [member] | Cash Flow Hedges [member] | Foreign Exchange Contracts [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Liabilities	(1)
Financial Liabilities at Fair Value Through Profit or Loss That Meet Definition of Held for Trading, Category [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Liabilities	(48)	(102)
Financial Liabilities at Fair Value Through Profit or Loss That Meet Definition of Held for Trading, Category [member] | Foreign Exchange Contracts [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Liabilities	(47)	(99)
Financial Liabilities at Fair Value Through Profit or Loss That Meet Definition of Held for Trading, Category [member] | Embedded and Other Derivatives [member]
Disclosure of detailed information about hedging instruments [line items]
Fair value of Liabilities	£ (1)	£ (3)

XML

Financial instruments and related disclosures - Fair Values of Derivatives Held (Parenthetical) (Detail) - Foreign Exchange Contracts [member]	Dec. 31, 2017	Dec. 31, 2016
Financial Assets at Fair Value Through Profit or Loss, Mandatory Measured at Fair Value, Category [member] | Net Investment Hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Principal amount	6,333,000,000	5,362,000,000
Financial Assets at Fair Value Through Profit or Loss, Mandatory Measured at Fair Value, Category [member] | Cash Flow Hedges [member]
Disclosure of detailed information about hedging instruments [line items]
Principal amount	38,000,000	170,000,000
Financial Assets at Fair Value Through Profit or Loss, Classified as Held for Trading, Category [member]
Disclosure of detailed information about hedging instruments [line items]
Principal amount	14,449,000,000	14,943,000,000

XML

Financial instruments and related disclosures - Schedule of Offsetting of Financial Assets and Liabilities (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Trade and Other Receivable [member]
Disclosure of offsetting of financial assets and financial liabilities [Line Items]
Gross financial assets/(liabilities)	£ 5,191	£ 5,136
Gross financial (Liabilities)/assets set off	(1)	(1)
Net financial assets/(liabilities)per balance sheet	5,190	5,135
Related amounts not set off in the balance sheet	(31)	(29)
Net amount	5,159	5,106
Derivative financial assets [member]
Disclosure of offsetting of financial assets and financial liabilities [Line Items]
Gross financial assets/(liabilities)	76	156
Net financial assets/(liabilities)per balance sheet	76	156
Related amounts not set off in the balance sheet	(64)	(117)
Net amount	12	39
Trades and other payables [member]
Disclosure of offsetting of financial assets and financial liabilities [Line Items]
Gross financial assets/(liabilities)	(20,130)	(11,042)
Gross financial (Liabilities)/assets set off	1	1
Net financial assets/(liabilities)per balance sheet	(20,129)	(11,041)
Related amounts not set off in the balance sheet	31	29
Net amount	(20,098)	(11,012)
Derivative financial liabilities [member]
Disclosure of offsetting of financial assets and financial liabilities [Line Items]
Gross financial assets/(liabilities)	(74)	(194)
Net financial assets/(liabilities)per balance sheet	(74)	(194)
Related amounts not set off in the balance sheet	64	117
Net amount	£ (10)	£ (77)

XML

Financial instruments and related disclosures - Schedule of Debt Interest Rate Repricing (Detail) - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of debt interest rate repricing [Line Items]
Total debt	£ (17,023)	£ (18,726)
Total interest bearing	(16,974)	(18,723)
Non-interest bearing	(49)	(3)
Total debt	(17,023)	(18,726)
Floating and Fixed Rate Debt [member] | Later Than One Year [Member]
Disclosure of debt interest rate repricing [Line Items]
Total debt	(2,802)	(4,106)
Total debt	(2,802)	(4,106)
Floating and Fixed Rate Debt [member] | Between one and two years [member]
Disclosure of debt interest rate repricing [Line Items]
Total debt	(1,340)	(2,216)
Total debt	(1,340)	(2,216)
Floating and Fixed Rate Debt [member] | Between two and three years [member]
Disclosure of debt interest rate repricing [Line Items]
Total debt	(1,076)	(1,277)
Total debt	(1,076)	(1,277)
Floating and Fixed Rate Debt [member] | Between Three and Four Years [Member]
Disclosure of debt interest rate repricing [Line Items]
Total debt	(16)
Total debt	(16)
Floating and Fixed Rate Debt [member] | Between four and five years [member]
Disclosure of debt interest rate repricing [Line Items]
Total debt	(1,475)
Total debt	(1,475)
Floating and Fixed Rate Debt [member] | Between Five and Ten Years [Member]
Disclosure of debt interest rate repricing [Line Items]
Total debt	(3,664)	(4,082)
Total debt	(3,664)	(4,082)
Floating and Fixed Rate Debt [member] | Greater Than Ten Years [Member]
Disclosure of debt interest rate repricing [Line Items]
Total debt	(6,650)	(7,045)
Total debt	(6,650)	(7,045)
Fixed interest rate [member]
Disclosure of debt interest rate repricing [Line Items]
Total interest bearing	(16,209)	(17,342)
Floating interest rate [member]
Disclosure of debt interest rate repricing [Line Items]
Total interest bearing	£ (765)	£ (1,381)

XML

Financial instruments and related disclosures - Impact of Non-functional Currency Foreign Exchange Exposures (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
10 cent appreciation of the US Dollar [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	£ 76,000,000	£ 77,000,000
(Increase)/decrease in net debt	(637,000,000)	(746,000,000)
10 cent appreciation of the Euro [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	(5,000,000)	18,000,000
(Increase)/decrease in net debt	197,000,000	190,000,000
10 Yen appreciation of the Yen [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	9,000,000	1,000,000
(Increase)/decrease in net debt	(4,000,000)	(11,000,000)
10 cent depreciation of US Dollar [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	(66)	(66)
(Increase)/decrease in net debt	549,000,000	634,000,000
10 cent depreciation of Euro [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	4	(16)
(Increase)/decrease in net debt	(165,000,000)	(160,000,000)
Yen Exchange Rates [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	(8)	(1)
10 cent depreciation of Yen [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
(Increase)/decrease in net debt	£ 4,000,000	£ 10,000,000

XML

Financial instruments and related disclosures - Impact of Interest Rate Currency Movements (Detail) - GBP (£) £ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
1% (100 basis points) increase in sterling interest rates [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	£ 24	£ 3
1% (100 Basis Points) Increase in US Dollar Interest Rates [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	(24)	(3)
1% (100 Basis Points) Increase in Euro Interest Rates [Member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Increase/(decrease) in income	£ 5	£ 3

XML

Financial instruments and related disclosures - Summary of Maturity Analysis for Non-derivative Financial Liabilities (Detail) - GBP (£)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Finance charge o s obligations ce under finance leases £m	£ (66)	£ (64)
Finance charge on obligations under finance leases	12	3
Non Derivatives Financial Liabilities [Member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(17,137,000,000)	(18,849,000,000)
Interest on debt	8,510,000,000	(9,410,000,000)
Finance charge o s obligations ce under finance leases £m	(66,000,000)	(64,000,000)
Finance charge on obligations under finance leases	(12,000,000)	(3,000,000)
and not t	(29,803,000,000)	(29,466,000,000)
Total	(55,528,000,000)	(57,792,000,000)
Non Derivatives Financial Liabilities [Member] | Not later than one year [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(2,802,000,000)	(4,108,000,000)
Interest on debt	555,000,000	(705,000,000)
Finance charge o s obligations ce under finance leases £m	(23,000,000)	(23,000,000)
Finance charge on obligations under finance leases	(2,000,000)	(2,000,000)
and not t	(21,521,000,000)	(11,621,000,000)
Total	(24,903,000,000)	(16,459,000,000)
Non Derivatives Financial Liabilities [Member] | Between one and two years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(1,344,000,000)	(2,218,000,000)
Interest on debt	497,000,000	(566,000,000)
Finance charge o s obligations ce under finance leases £m	(27,000,000)	(22,000,000)
Finance charge on obligations under finance leases	(2,000,000)	(1,000,000)
and not t	(853,000,000)	(8,784,000,000)
Total	(2,723,000,000)	(11,591,000,000)
Non Derivatives Financial Liabilities [Member] | Between two and three years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(1,078,000,000)	(1,282,000,000)
Interest on debt	488,000,000	(503,000,000)
Finance charge o s obligations ce under finance leases £m	(8,000,000)	(12,000,000)
Finance charge on obligations under finance leases	(1,000,000)
and not t	(813,000,000)	(961,000,000)
Total	(2,388,000,000)	(2,758,000,000)
Non Derivatives Financial Liabilities [Member] | Between Three and Four Years [Member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(16,000,000)
Interest on debt	488,000,000	(496,000,000)
Finance charge o s obligations ce under finance leases £m	(2,000,000)	(7,000,000)
Finance charge on obligations under finance leases	(1,000,000)
and not t	(784,000,000)	(786,000,000)
Total	(1,291,000,000)	(1,289,000,000)
Non Derivatives Financial Liabilities [Member] | Between four and five years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(1,483,000,000)
Interest on debt	468,000,000	(496,000,000)
Finance charge o s obligations ce under finance leases £m	(1,000,000)
Finance charge on obligations under finance leases	(1,000,000)
and not t	(752,000,000)	(705,000,000)
Total	(2,705,000,000)	(1,201,000,000)
Non Derivatives Financial Liabilities [Member] | Between Five and Ten Years [Member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(3,694,000,000)	(4,117,000,000)
Interest on debt	2,018,000,000	(2,122,000,000)
Finance charge o s obligations ce under finance leases £m	(5,000,000)
Finance charge on obligations under finance leases	(5,000,000)
and not t	(3,609,000,000)	(3,474,000,000)
Total	(9,331,000,000)	(9,713,000,000)
Non Derivatives Financial Liabilities [Member] | Greater Than Ten Years [Member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Debt	(6,720,000,000)	(7,124,000,000)
Interest on debt	3,996,000,000	(4,522,000,000)
and not t	(1,471,000,000)	(3,135,000,000)
Total	£ (12,187,000,000)	£ (14,781,000,000)

XML

Financial instruments and related disclosures - Summary Anticipated Contractual Cash Flows for Derivative Instruments, Excluding Embedded Derivatives and Equity Options, Using Undiscounted Cash Flows (Detail) - Derivative Instruments [Member] - GBP (£) £ in Millions	Dec. 31, 2017	Dec. 31, 2016
Disclosure of detailed information about financial instruments [line items]
Receivables	£ 20,319	£ 21,286
Payables	(20,326)	(21,323)
Not later than one year [member]
Disclosure of detailed information about financial instruments [line items]
Receivables	20,319	21,266
Payables	£ (20,326)	(21,303)
Between one and two years [member]
Disclosure of detailed information about financial instruments [line items]
Receivables		20
Payables		£ (20)

XML

Employee Share Schemes - Additional Information (Detail) £ / shares in Units, shares in Thousands, £ in Millions	12 Months Ended
	Dec. 31, 2017 GBP (£) shares £ / shares	Dec. 31, 2017 shares £ / shares $ / shares	Dec. 31, 2016 GBP (£) shares £ / shares	Dec. 31, 2016 $ / shares	Dec. 31, 2015 GBP (£) shares £ / shares	Dec. 31, 2015 $ / shares
Disclosure of employee share schemes [Line Items]
Cost of share-based incentive plans | £	£ 347		£ 338		£ 349
Savings-Related Share Option Schemes [member]
Disclosure of employee share schemes [Line Items]
Percentage of share options granted at market price	20.00%
Number of options granted	2,000
Weighted average fair value of options granted | £ / shares	£ 2.08	£ 2.08
Number share options were not exercisable	6,700	6,700
Share Value Plan [member]
Disclosure of employee share schemes [Line Items]
Cost of share-based incentive plans | £	£ 276		£ 271		£ 307
Expected future dividend yield percentage share granted	4.80%		4.50%		5.70%
Number of awards granted	13,018		12,983		13,019
Weighted average fair value of awards | £ / shares	£ 13.68		£ 14.97		£ 11.57
Share Value Plan [member] | American Depositary Shares [member]
Disclosure of employee share schemes [Line Items]
Number of awards granted	6,610		6,589		7,198
Weighted average fair value of awards | $ / shares		£ 35.63		$ 39.18		$ 35.66
Performance Share Plan [member]
Disclosure of employee share schemes [Line Items]
Cost of share-based incentive plans | £	£ 47		£ 39		£ 26
Number of awards granted	3,900
Weighted average fair value of awards | £ / shares	£ 11.09
Number of outstanding awards	12,900	12,900
Performance Share Plan [member] | American Depositary Shares [member]
Disclosure of employee share schemes [Line Items]
Number of awards granted	1.0
Weighted average fair value of awards | $ / shares		£ 32.85
Number of outstanding awards	3,200	3,200
Employee share ownership plan [member]
Disclosure of employee share schemes [Line Items]
Number of treasury shares acquired by ESOP trusts | £	£ 610

XML

Employee Share Schemes - Schedule of Number of Shares and ADS Issuable (Detail) - Share Value Plan [member] shares in Thousands	12 Months Ended
	Dec. 31, 2017 shares £ / shares	Dec. 31, 2017 shares $ / shares	Dec. 31, 2016 shares £ / shares	Dec. 31, 2016 shares $ / shares	Dec. 31, 2015 shares £ / shares	Dec. 31, 2015 shares $ / shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of shares, Beginning balance	32,855	32,855	32,577	32,577	32,912	32,912
Number of shares, Awards granted	13,018	13,018	12,983	12,983	13,019	13,019
Number of shares, Awards exercised	(10,596)	(10,596)	(11,198)	(11,198)	(11,476)	(11,476)
Number of shares, Awards cancelled	(1,352)	(1,352)	(1,507)	(1,507)	(1,878)	(1,878)
Number of shares, Ending balance	33,925	33,925	32,855	32,855	32,577	32,577
Weighted fair value, Awards granted | £ / shares	£ 13.68		£ 14.97		£ 11.57
American Depositary Shares [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of shares, Beginning balance	17,083	17,083	17,520	17,520	21,227	21,227
Number of shares, Awards granted	6,610	6,610	6,589	6,589	7,198	7,198
Number of shares, Awards exercised	(5,674)	(5,674)	(6,214)	(6,214)	(8,878)	(8,878)
Number of shares, Awards cancelled	(627)	(627)	(812)	(812)	(2,027)	(2,027)
Number of shares, Ending balance	17,392	17,392	17,083	17,083	17,520	17,520
Weighted fair value, Awards granted | $ / shares		$ 35.63		$ 39.18		$ 35.66

XML

Employee Share Schemes - Summary of Valuation Model Used to Valuing Saving - Related Option to Arrive at the Share Based Payment Charge (Detail) - Share Options and Savings-Related Options [member] - £ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of share options and savings related options [Line Items]
Risk-free interest rate	0.54%	0.32%	0.88%
Dividend yield	5.90%	4.90%	6.50%
Volatility	23.00%	23.00%	21.00%
Expected life	3 years	3 years	3 years
Savings-related options grant price (including 20% discount)	£ 10.86	£ 12.95	£ 10.14

XML

Employee Share Schemes - Summary of Valuation Model Used to Valuing Saving - Related Option to Arrive at the Share Based Payment Charge (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Options and Savings-Related Options [member]
Disclosure of share options and savings related options [Line Items]
Savings-related options grant price discount	20.00%	20.00%	20.00%

XML

Employee Share Schemes - Summary of Option Outstanding (Detail) - Dec. 31, 2017 shares in Thousands	shares yr £ / shares	shares yr $ / shares
Share Option Schemes [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of Shares | shares	3,600	3,600
Share option schemes - shares Weighted exercise price	£ 11.86
Weighted average market price on exercise during year	£ 16.07
Weighted average remaining contractual life | yr	1.4	1.4
Share Option Schemes [member] | Top of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Range of exercise prices on options outstanding at year end	£ 12.21
Share Option Schemes [member] | Bottom of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Range of exercise prices on options outstanding at year end	£ 11.47
Share Option Schemes American Depositary Shares [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of Shares | shares	3,277	3,277
Share option schemes - shares Weighted exercise price | $ / shares		$ 39.62
Weighted average market price on exercise during year | $ / shares		$ 41.50
Weighted average remaining contractual life | yr	1.0	1.0
Share Option Schemes American Depositary Shares [member] | Top of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Range of exercise prices on options outstanding at year end | $ / shares		$ 48.66
Share Option Schemes American Depositary Shares [member] | Bottom of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Range of exercise prices on options outstanding at year end | $ / shares		$ 33.42
Savings-Related Share Option Schemes [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of Shares | shares	6,852	6,852
Share option schemes - shares Weighted exercise price	£ 10.77
Weighted average market price on exercise during year	£ 14.28
Weighted average remaining contractual life | yr	2.1	2.1
Savings-Related Share Option Schemes [member] | Top of range [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Range of exercise prices on options outstanding at year end	£ 12.95

XML

Employee Share Schemes - Summary of Shares Held for Share Award Schemes (Detail) - Employee share ownership plan [member] pure in Thousands, £ in Millions	Dec. 31, 2017 GBP (£)	Dec. 31, 2016 GBP (£)
Disclosure of terms and conditions of share-based payment arrangement [line items]
Shares held for share award schemes, Number of shares	66,558	42,571
Shares held for share award schemes, Nominal value	£ 17	£ 11
Shares held for share award schemes, Carrying value	399	285
Shares held for share award schemes, Market value	£ 880	£ 665
Shares held for share option schemes, Number of shares	139	139
Shares held for share option schemes, Nominal value	£ 0	£ 0
Shares held for share option schemes, Carrying value	1	1
Shares held for share option schemes, Market value	£ 2	£ 2

XML

Principal Group companies - Schedule of the Subsidiaries and Their Counties of Incorporation and the Equity Share Capital of These Entities wholly owned by the Group (Detail)	12 Months Ended
	Dec. 31, 2017
GlaxoSmithKline Argentina S.A. [member] | Argentina [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Argentina S.A.
Country of incorporation	Argentina
GlaxoSmithKline Australia Pty Ltd [Member] | Australia [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Australia Pty Ltd
Country of incorporation	Australia
GlaxoSmithKline Consumer Healthcare Australia Pty Ltd [member] | Australia [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare Australia Pty Ltd
Country of incorporation	Australia
GlaxoSmithKline Brasil Limitada [Member] | Brazil [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Brasil Limitada
Country of incorporation	Brazil
GlaxoSmithKline Consumer Healthcare Inc. [Member] | Canada [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare Inc.
Country of incorporation	Canada
GlaxoSmithKline Inc. [Member] | Canada [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Inc.
Country of incorporation	Canada
ID Biomedical Corporation of Quebec [Member] | Canada [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	ID Biomedical Corporation of Quebec
Country of incorporation	Canada
GlaxoSmithKline Limited [Member] | China (Hong Kong) [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Limited
Country of incorporation	China (Hong Kong)
Sino-American Tianjin Smith Kline and French Laboratories Ltd [Member] | China [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Sino-American Tianjin Smith Kline & French Laboratories Ltd
Country of incorporation	China
GlaxoSmithKline Consumer Healthcare Limited [member] | India [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare Limited
Country of incorporation	India
GlaxoSmithKline Pharmaceuticals Limited [member] | India [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Pharmaceuticals Limited
Country of incorporation	India
GlaxoSmithKline Consumer Healthcare Japan K.K. [member] | Japan [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare Japan K.K.
Country of incorporation	Japan
GlaxoSmithKline K.K. [member] | Japan [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline K.K.
Country of incorporation	Japan
ViiV Healthcare Kabushiki Kaisha [member] | Japan [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	ViiV Healthcare Kabushiki Kaisha
Country of incorporation	Japan
GlaxoSmithKline Pakistan Limited [member] | Pakistan [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Pakistan Limited
Country of incorporation	Pakistan
Glaxo Wellcome Manufacturing Pte Ltd. [member] | Singapore [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Glaxo Wellcome Manufacturing Pte Ltd.
Country of incorporation	Singapore
GlaxoSmithKline Korea Limited [member] | Republic of Korea [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Korea Limited
Country of incorporation	Republic of Korea
GlaxoSmithKline llaclari Sanayi ve Ticaret A.S. [member] | Turkey [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline llaclari Sanayi ve Ticaret A.S.
Country of incorporation	Turkey
GlaxoSmithKline Biologicals SA [Member] | Belgium [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Biologicals SA
Country of incorporation	Belgium
GlaxoSmithKline Pharmaceuticals S.A. [Member] | Belgium [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Pharmaceuticals SA
Country of incorporation	Belgium
GlaxoSmithKline Pharmaceuticals S.A. [Member] | Poland [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Pharmaceuticals S.A.
Country of incorporation	Poland
GlaxoSmithKline Biologicals S.A.S. [Member] | France [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Biologicals S.A.S.
Country of incorporation	France
GlaxoSmithKline Sante Grand Public SAS [Member] | France [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Sante Grand Public SAS
Country of incorporation	France
Laboratoire GlaxoSmithKline [Member] | France [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Laboratoire GlaxoSmithKline
Country of incorporation	France
ViiV Healthcare SAS [Member] | France [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	ViiV Healthcare SAS
Country of incorporation	France
GlaxoSmithKline Consumer Healthcare GmbH and Co. KG [member] | Germany [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare GmbH & Co. KG
Country of incorporation	Germany
GlaxoSmithKline GmbH and Co. KG [member] | Germany [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline GmbH & Co. KG
Country of incorporation	Germany
GSK Vaccines GmbH [Member] | Germany [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GSK Vaccines GmbH
Country of incorporation	Germany
GlaxoSmithKline Consumer Healthcare S.p.A. [Member] | Italy [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare S.p.A.
Country of incorporation	Italy
GlaxoSmithKline S.p.A. [Member] | Italy [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline S.p.A.
Country of incorporation	Italy
GSK Vaccines S.r.l. [Member] | Italy [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GSK Vaccines S.r.l.
Country of incorporation	Italy
GlaxoSmithKline B.V. [Member] | Netherlands [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline B.V.
Country of incorporation	Netherlands
GlaxoSmithKline Consumer Healthcare S p z o o [member] | Poland [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Haelthcare Sp.z.o.o.
Country of incorporation	Poland
GSK Services Sp z o.o. [Member] | Poland [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GSK Services Sp z o.o.
Country of incorporation	Poland
GlaxoSmithKline Trading Services Limited [Member] | Ireland [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Trading Services Limited
Country of incorporation	Republic of Ireland
GlaxoSmithKline Healthcare AO [member] | Russia [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Healthcare AO
Country of incorporation	Russia
GlaxoSmithKline S.A. [Member] | Spain [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline S.A.
Country of incorporation	Spain
Laboratorios ViiV Healthcare, S.L. [Member] | Spain [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Laboratorios ViiV Healthcare, S.L.
Country of incorporation	Spain
Novartis Consumer Health S.A. [Member] | Switzerland [Member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Novartis Consumer Health S.A.
Country of incorporation	Switzerland
Block Drug Company Inc. [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Block Drug Company, Inc.
Country of incorporation	US
Corixa Corporation [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Corixa Corporation
Country of incorporation	US
GlaxoSmithKline Capital Inc. [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Capital Inc.
Country of incorporation	US
GlaxoSmithKline Consumer Health Care L P [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare, L.P.
Country of incorporation	US
GlaxoSmithKline Holdings (Americas) Inc. [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Holdings (Americas) Inc.
Country of incorporation	US
GlaxoSmithKline LLC [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline LLC
Country of incorporation	US
Human Genome Sciences, Inc. [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Human Genome Sciences, Inc.
Country of incorporation	US
GSK Consumer Health, Inc [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GSK Consumer Health, Inc. (formerly Novartis Consumer Health, Inc.)
Country of incorporation	US
S.R One, Limited [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	S.R. One, Limited
Country of incorporation	US
Stiefel Laboratories, Inc. [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Stiefel Laboratories, Inc.
Country of incorporation	US
Vii V Health Care Company [member] | US [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	ViiV Healthcare Company
Country of incorporation	US
Glaxo Group Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Glaxo Group Limited
Country of incorporation	England
Glaxo Operations UK Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Glaxo Operations UK Limited
Country of incorporation	England
GlaxoSmithKline Capital PLC [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Capital plc
Country of incorporation	England
GlaxoSmithKline Consumer Healthcare Holdings Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare Holdings Limited
Country of incorporation	England
GlaxoSmithKline Consumer Healthcare (UK) Trading Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Consumer Healthcare (UK) Trading Limited
Country of incorporation	England
GlaxoSmithKline Export Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Export Limited
Country of incorporation	England
GlaxoSmithKline Finance PLC [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Finance plc
Country of incorporation	England
GlaxoSmithKline Holdings Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Holdings Limited
Country of incorporation	England
GlaxoSmithKline Research and Development Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Research & Development Limited
Country of incorporation	England
GlaxoSmithKline Services Unlimited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline Services Unlimited
Country of incorporation	England
GlaxoSmithKline UK Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	GlaxoSmithKline UK Limited
Country of incorporation	England
Setfirst Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	Setfirst Limited
Country of incorporation	England
SmithKline Beecham Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	SmithKline Beecham Limited
Country of incorporation	England
ViiV Health Care Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	ViiV Healthcare Limited
Country of incorporation	England
ViiV Healthcare UK Limited [member] | UK [member]
Disclosure of subsidiaries [line items]
Name of subsidiary	ViiV Healthcare UK Limited
Country of incorporation	England

XML

Principal Group companies - Schedule of the Subsidiaries and Their Counties of Incorporation and the Equity Share Capital of These Entities wholly owned by the Group (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017
Australia [member] | GlaxoSmithKline Consumer Healthcare Australia Pty Ltd [member]
Disclosure of subsidiaries [line items]
Country of incorporation	Australia
Proportion of ownership interest in subsidiary	63.50%
Canada [member] | GlaxoSmithKline Consumer Healthcare Inc. [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	Canada
Proportion of ownership interest in subsidiary	63.50%
Canada [member] | ID Biomedical Corporation of Quebec [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	Canada
China [member] | Sino-American Tianjin Smith Kline and French Laboratories Ltd [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	China
Proportion of ownership interest in subsidiary	34.90%
India [member] | GlaxoSmithKline Consumer Healthcare Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	India
Proportion of ownership interest in subsidiary	72.50%
India [member] | GlaxoSmithKline Pharmaceuticals Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	India
Proportion of ownership interest in subsidiary	75.00%
Japan [member] | GlaxoSmithKline Consumer Healthcare Japan K.K. [member]
Disclosure of subsidiaries [line items]
Country of incorporation	Japan
Proportion of ownership interest in subsidiary	63.50%
Japan [member] | ViiV Healthcare Kabushiki Kaisha [member]
Disclosure of subsidiaries [line items]
Country of incorporation	Japan
Proportion of ownership interest in subsidiary	78.30%
Pakistan [member] | GlaxoSmithKline Pakistan Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	Pakistan
Proportion of ownership interest in subsidiary	82.60%
France [Member] | GlaxoSmithKline Biologicals S.A.S. [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	France
France [Member] | GlaxoSmithKline Sante Grand Public SAS [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	France
Proportion of ownership interest in subsidiary	6350.00%
France [Member] | Laboratoire GlaxoSmithKline [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	France
France [Member] | ViiV Healthcare SAS [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	France
Proportion of ownership interest in subsidiary	78.30%
Germany [Member] | GlaxoSmithKline Consumer Healthcare GmbH and Co. KG [member]
Disclosure of subsidiaries [line items]
Country of incorporation	Germany
Proportion of ownership interest in subsidiary	63.50%
Italy [member] | GlaxoSmithKline Consumer Healthcare S.p.A. [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	Italy
Proportion of ownership interest in subsidiary	63.50%
Poland [member] | GlaxoSmithKline Consumer Healthcare S p z o o [member]
Disclosure of subsidiaries [line items]
Country of incorporation	Poland
Proportion of ownership interest in subsidiary	63.50%
Spain [Member] | Laboratorios ViiV Healthcare, S.L. [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	Spain
Proportion of ownership interest in subsidiary	78.30%
Switzerland [Member] | Novartis Consumer Health S.A. [Member]
Disclosure of subsidiaries [line items]
Country of incorporation	Switzerland
Proportion of ownership interest in subsidiary	63.50%
US [member] | Block Drug Company Inc. [member]
Disclosure of subsidiaries [line items]
Country of incorporation	US
Proportion of ownership interest in subsidiary	63.50%
US [member] | GlaxoSmithKline Consumer Health Care L P [member]
Disclosure of subsidiaries [line items]
Country of incorporation	US
Proportion of ownership interest in subsidiary	55.90%
US [member] | GSK Consumer Health, Inc [member]
Disclosure of subsidiaries [line items]
Country of incorporation	US
Proportion of ownership interest in subsidiary	63.50%
US [member] | Vii V Health Care Company [member]
Disclosure of subsidiaries [line items]
Country of incorporation	US
Proportion of ownership interest in subsidiary	78.30%
UK [member] | Glaxo Group Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | Glaxo Operations UK Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | GlaxoSmithKline Capital PLC [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | GlaxoSmithKline Consumer Healthcare Holdings Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
Proportion of ownership interest in subsidiary	63.50%
UK [member] | GlaxoSmithKline Consumer Healthcare (UK) Trading Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
Proportion of ownership interest in subsidiary	63.50%
UK [member] | GlaxoSmithKline Export Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | GlaxoSmithKline Finance PLC [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | GlaxoSmithKline Holdings Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | GlaxoSmithKline Research and Development Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | GlaxoSmithKline Services Unlimited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | GlaxoSmithKline UK Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | Setfirst Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | SmithKline Beecham Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
UK [member] | ViiV Health Care Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
Proportion of ownership interest in subsidiary	78.30%
UK [member] | ViiV Healthcare UK Limited [member]
Disclosure of subsidiaries [line items]
Country of incorporation	England
Proportion of ownership interest in subsidiary	78.30%

XML

Legal Proceedings - Additional Information (Detail) £ in Millions, $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($)	Feb. 28, 2018 USD ($)	Dec. 31, 2017 GBP (£)	Dec. 31, 2016 GBP (£)	Feb. 12, 2016 GBP (£)
Disclosure of Legal Proceedings [line items]
Provisions for legal and other disputes			£ 186.0	£ 344.0
Acts of violence [member]
Disclosure of Legal Proceedings [line items]
Amount of compensation awarded to plaintiff | $		$ 3
UK Competition and Markets Authority [member]
Disclosure of Legal Proceedings [line items]
Fine paid by group					£ 37.6
Fine paid by other companies					£ 7.4
SEC/DOJ and SFO Anti-corruption enquiries [member]
Disclosure of Legal Proceedings [line items]
Civil Penalty | $	$ 20
Zofran [Member] | Commencement of major litigation [member] | United States [Member]
Disclosure of Legal Proceedings [line items]
Number of personal injury cases		420
Zofran [Member] | Commencement of major litigation [member] | Massachusetts United States [Member]
Disclosure of Legal Proceedings [line items]
Number of personal injury cases		406