N-CSR

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF

REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-21780

MFS SERIES TRUST XII

(Exact name of registrant as specified in charter)

111 Huntington Avenue, Boston, Massachusetts 02199

(Address of principal executive offices) (Zip code)

Susan S. Newton

Massachusetts Financial Services Company

111 Huntington Avenue

Boston, Massachusetts 02199

(Name and address of agents for service)

Registrant’s telephone number, including area code: (617) 954-5000

Date of fiscal year end: October 31

Date of reporting period: October 31, 2012*

* This Form N-CSR pertains to the following series of the Registrant, MFS Equity Opportunities Fund (formerly MFS Sector Rotational Fund). The remaining series of the Registrant, MFS Lifetime Retirement Income Fund, MFS Lifetime 2010 Fund, MFS Lifetime 2015 Fund, MFS Lifetime 2020 Fund, MFS Lifetime 2025 Fund, MFS Lifetime 2030 Fund, MFS Lifetime 2035 Fund, MFS Lifetime 2040 Fund, MFS Lifetime 2045 Fund, MFS Lifetime 2050 Fund, and MFS Lifetime 2055 Fund have fiscal year ends of April 30.

ITEM 1. REPORTS TO STOCKHOLDERS.

ANNUAL REPORT

October 31, 2012

MFS® EQUITY OPPORTUNITIES FUND

MSR-ANN

MFS® EQUITY OPPORTUNITIES FUND

CONTENTS

Letter from the Chairman and CEO	1
Portfolio composition	2
Management review	3
Performance summary	5
Expense table	8
Portfolio of investments	10
Statement of assets and liabilities	13
Statement of operations	15
Statements of changes in net assets	16
Financial highlights	17
Notes to financial statements	23
Report of independent registered public accounting firm	33
Trustees and officers	34
Board review of investment advisory agreement	39
Proxy voting policies and information	43
Quarterly portfolio disclosure	43
Further information	43
Federal tax information	43
MFS® privacy notice	44
Contact information    back cover

The report is prepared for the general information of shareholders.

It is authorized for distribution to prospective investors only when preceded or accompanied by a current prospectus.

NOT FDIC INSURED Ÿ MAY LOSE VALUE Ÿ NO BANK GUARANTEE

LETTER FROM THE CHAIRMAN AND CEO

Dear Shareholders:

As 2012 winds down, economic uncertainty continues to dominate world financial markets. In the United States, all eyes are riveted to the ongoing budget deal

negotiations and the specter of a “fiscal cliff.” Overseas, we see growth slowing in China and Japan, and the eurozone has entered its second recession in four years against a backdrop of double-digit unemployment and the continuing sovereign debt crisis.

Amidst the instability, there are silver linings — especially in the U.S. where the labor and housing markets have picked up, consumer confidence has risen and industrial output has increased. Additionally, a U.S. budgetary compromise could propel markets, unleashing pent-up spending and investments, which would help to revive both the U.S. and global economies.

As always, managing risk in the face of uncertainty remains a top priority for investors. At MFS®, an emphasis on global research and our disciplined risk management approach anchor our uniquely collaborative investment process. Our global team of more than 200 investment professionals shares ideas and evaluates opportunities across continents, investment disciplines, and asset classes — all with a goal of building better insights, and ultimately better results — for our clients.

We are mindful of the many economic challenges we face locally, nationally and globally. It is more important than ever to maintain a long-term view, employ time-tested principles, such as asset allocation and diversification, and work closely with investment advisors to identify and pursue the most suitable opportunities.

Respectfully,

Robert J. Manning

Chairman and Chief Executive Officer

MFS Investment Management®

December 14, 2012

The opinions expressed in this letter are subject to change, may not be relied upon for investment advice, and no forecasts can be guaranteed.

1

PORTFOLIO COMPOSITION

Portfolio structure

Top ten holdings
Discover Financial Services	3.9%
SolarWinds, Inc.	3.7%
Time Warner Cable, Inc.	3.2%
Delphi Automotive PLC	3.0%
Copa Holdings S.A., “A”	2.9%
Comcast Corp., “Special A”	2.9%
Apple, Inc.	2.9%
Pfizer, Inc.	2.8%
Ingredion, Inc.	2.7%
Aetna, Inc.	2.7%

Equity sectors
Financial Services	24.8%
Consumer Staples	11.0%
Health Care	10.2%
Technology	8.6%
Leisure	8.3%
Transportation	7.6%
Retailing	6.1%
Energy	4.8%
Industrial Goods & Services	4.8%
Autos & Housing	4.8%
Utilities & Communications	4.3%
Special Products & Services	2.5%
Basic Materials	1.6%

Percentages are based on net assets as of 10/31/12.

The portfolio is actively managed and current holdings may be different.

2

MANAGEMENT REVIEW

Summary of Results

For the twelve months ended October 31, 2012, Class A shares of the MFS Equity Opportunities Fund (the “fund”) provided a total return of 15.50%, at net asset value. This compares with a return of 14.97% for the fund’s benchmark, the Russell 1000 Index.

Market Environment

Just prior to the beginning of the reporting period, markets were roiled by several global concerns. These included the aftermath of the U.S. sovereign debt-ceiling debacle, the path of eurozone integration and the scope of its bailout facilities, and the likelihood of a Chinese hard landing. Amidst this turmoil, global equity markets had declined sharply and credit spreads widened. At the same time, global consumer and producer sentiment indicators had fallen precipitously, while highly-rated sovereign bond yields hit multi-decade lows.

During the first half of the period, however, additional liquidity from the U.S. Federal Reserve (Fed), in the form of “Operation Twist”, and the European Central Bank (ECB), in the form of 3-year, Long Term Refinancing Operations, or LTROs, coupled with healthier global macroeconomic conditions led by moderate but sustained U.S. growth, ushered in improved market dynamics.

During the latter part of the period, market trends were more mixed. Worsening conditions were driven by broadly weaker global macroeconomic indicators, as well as renewed concerns over the eurozone’s capacity and determination to address its ongoing crisis. However, broad market sentiment remained relatively resilient, as equity markets generally maintained gains and credit spreads did not indicate deterioration. A new round of monetary easing by the Fed (QE3) and the ECB (rate cut and a new bond purchase facility) towards the end of the period instilled additional confidence in risk markets. Nonetheless, towards the end of the period, weaker equity earnings reports and declining forward guidance caused market sentiment to soften.

Contributors to Performance

Stock selection and, to a lesser extent, an overweight position in the financial services sector was a positive factor for performance relative to the Russell 1000 Index. Within this sector, holdings of credit card company Discover Financial Services and insurance company Allied World Assurance Co. ^(h) were among the fund’s top relative contributors. Shares of Discover Financial Services rose largely in response to the company’s increase of its share repurchase program during the reporting period. The stock of Allied World Assurance strengthened as a result of better-than-expected earnings driven by significant growth in their property & specialty reinsurance segment.

The fund’s underweight position in the energy sector benefited relative returns as the sector underperformed the benchmark. Security selection and an underweight position in the technology sector also contributed to relative performance. Within the technology sector, the timing of the fund’s ownership in shares of information technology infrastructure management provider SolarWinds aided relative returns.

3

Management Review – continued

Additionally, stock selection in the consumer staples sector supported relative performance. Within this sector, the holdings of ingredient provider Ingredion Inc. contributed to relative results.

Top relative contributors in other sectors included cable telecommunications company Time Warner Cable, airline services provider Copa Holdings, clothing retailer Gap ^(h), and hospital operator HCA. Shares of Copa appreciated during the reporting period as the company benefited from growing Latin America air travel and increased revenue per passenger. The fund’s timing of ownership in shares of automotive parts companies Delphi Automotive and O’Reilly Automotive ^(h) also aided relative performance.

Detractors from Performance

Stock selection and, to a lesser extent, an underweight position in the utilities & communications sector detracted from relative performance. The fund’s holdings of power generation company NRG Energy ^(h) held back relative returns as the stock underperformed the benchmark over the reporting period. Additionally, the fund’s overweight position in integrated electric power company AES Corp. hindered relative results. Shares of AES declined over the period largely due to generally weak industry pricing and reports of a number of power outage incidents suffered by a plant located in Chile.

Security selection in the basic materials sector was another negative factor for relative performance. Holdings of iron ore miner Cliffs Natural Resources and steel producer Steel Dynamics ^(h) were among the fund’s top relative detractors.

Elsewhere, holdings of specialty retailer Zumiez Inc. ^(b), truckload carrier Swift Transportation ^(b)(h), speech and imaging software firm Nuance Communications ^(h), automotive supplies manufacturer Lear Corp. ^(h), and women’s apparel company ANN INC. ^(b) dampened relative performance as all five stocks turned in weak performance for the period.

Respectfully,

Matthew Krummell

Portfolio Manager

(b) Security is not a benchmark constituent.

(h) Security was not held in the portfolio at period end.

The views expressed in this report are those of the portfolio manager only through the end of the period of the report as stated on the cover and do not necessarily reflect the views of MFS or any other person in the MFS organization. These views are subject to change at any time based on market or other conditions, and MFS disclaims any responsibility to update such views. These views may not be relied upon as investment advice or an indication of trading intent on behalf of any MFS portfolio. References to specific securities are not recommendations of such securities, and may not be representative of any MFS portfolio’s current or future investments.

4

PERFORMANCE SUMMARY THROUGH 10/31/12

The following chart illustrates a representative class of the fund’s historical performance in comparison to its benchmark(s). Performance results include the deduction of the maximum applicable sales charge and reflect the percentage change in net asset value, including reinvestment of dividends and capital gains distributions. The performance of other share classes will be greater than or less than that of the class depicted below. Benchmarks are unmanaged and may not be invested in directly. Benchmark returns do not reflect sales charges, commissions or expenses. (See Notes to Performance Summary.)

Performance data shown represents past performance and is no guarantee of future results. Investment return and principal value fluctuate so your shares, when sold, may be worth more or less than the original cost; current performance may be lower or higher than quoted. The performance shown does not reflect the deduction of taxes, if any, that a shareholder would pay on fund distributions or the redemption of fund shares.

Growth of a Hypothetical $10,000 Investment

5

Performance Summary – continued

Total Returns as of: 10/31/12

Average annual without sales charge

	Share class	Class inception date	1-yr	5-yr	10-yr	Life (t)
	A	8/30/00	15.50%	(0.59)%	8.15%	N/A
	B	1/03/07	14.56%	(1.31)%	N/A	1.42%
	C	3/01/04	14.63%	(1.30)%	N/A	4.63%
	I	2/28/11	15.79%	N/A	N/A	5.16%
	R1	5/01/08	14.66%	N/A	N/A	0.23%
	R2	5/01/08	15.16%	N/A	N/A	0.72%
	R3	5/01/08	15.51%	N/A	N/A	0.98%
	R4	5/01/08	15.79%	N/A	N/A	1.24%
	R5 (formerly Class W)	3/03/08	15.68%	N/A	N/A	1.91%
Comparative benchmark
	Russell 1000 Index (f)		14.97%	0.53%	7.31%	N/A
Average annual with sales charge
	A With Initial Sales Charge (5.75%)		8.86%	(1.76)%	7.51%	N/A
	B With CDSC (Declining over six years from 4% to 0%) (x)		10.56%	(1.70)%	N/A	1.26%
	C With CDSC (1% for 12 months) (x)		13.63%	(1.30)%	N/A	4.63%

Class I, R1, R2, R3, R4 and R5 shares do not have a sales charge.

CDSC – Contingent Deferred Sales Charge.

As further discussed in Note 5 in the Notes to Financial Statements, on May 10, 2012, sales of Class W shares (including exchanges) were suspended. On May 11, 2012, certain Class W shares were automatically converted to Class I shares. Shareholders of certain Class W shares became shareholders of Class I and received Class I shares with a total net asset value equal to their Class W shares at the time of the conversion. On May 30, 2012, remaining Class W shares, which represented MFS seed money, were redesignated Class R5. Class R5 shares are generally available only to certain eligible retirement plans and to funds distributed by MFD. Class R5 shares do not pay a 12b-1 distribution fee or sub-accounting costs. On June 1, 2012, Class R5 shares were offered for sale to the public. For further information about the fund’s fee arrangements and changes to those fee arrangements, please see Note 3 in the Notes to Financial Statements.

(f) Source: FactSet Research Systems Inc.

(t) For the period from the class inception date through the stated period end (for those share classes with less than 10 years of performance history). No comparative benchmark performance information is provided for “life” periods. (See Notes to Performance Summary.)

(x) Assuming redemption at the end of the applicable period.

6

Performance Summary – continued

Benchmark Definition

Russell 1000 Index – constructed to provide a comprehensive barometer for the large-cap segment of the U.S. equity universe based on total market capitalization, which represents approximately 92% of the investable U.S. equity market.

It is not possible to invest directly in an index.

Notes to Performance Summary

Performance information in the chart and tables for periods prior to January 3, 2007, reflect performance information of the Penn Street Advisors Sector Rotational Portfolio, the fund’s predecessor (the Predecessor Fund). On January 3, 2007, the fund acquired all of the assets of the Predecessor Fund pursuant to an agreement and plan of reorganization, in exchange for Class A and Class C shares of the fund. The dates in the table are the inception dates for the predecessor fund’s Class A and C shares.

Prior to February 1, 2010, Valley Forge Capital Advisors, Inc. (Valley Forge) served as the sub-adviser for the fund. Effective February 1, 2010, Valley Forge no longer served as the sub-adviser of the fund and MFS assumed responsibility for the day-to-day management of the funds portfolio in its capacity as the funds investment adviser.

Average annual total return represents the average annual change in value for each share class for the periods presented. Life returns are presented where the share class has less than 10 years of performance history and represent the average annual total return from the class inception date to the stated period end date. As the fund’s share classes may have different inception dates, the life returns may represent different time periods and may not be comparable. As a result, no comparative benchmark performance information is provided for life periods.

Performance results reflect any applicable expense subsidies and waivers in effect during the periods shown. Without such subsidies and waivers the fund’s performance results would be less favorable. Please see the prospectus and financial statements for complete details.

Performance results do not include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles and may differ from amounts reported in the financial highlights.

From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

7

EXPENSE TABLE

Fund expenses borne by the shareholders during the period, May 1, 2012 through October 31, 2012

As a shareholder of the fund, you incur two types of costs: (1) transaction costs, including sales charges (loads) on certain purchase or redemption payments, and (2) ongoing costs, including management fees; distribution and service (12b-1) fees; and other fund expenses. This example is intended to help you understand your ongoing costs (in dollars) of investing in the fund and to compare these costs with the ongoing costs of investing in other mutual funds.

The example is based on an investment of $1,000 invested at the beginning of the period and held for the entire period May 1, 2012 through October 31, 2012.

Actual Expenses

The first line for each share class in the following table provides information about actual account values and actual expenses. You may use the information in this line, together with the amount you invested, to estimate the expenses that you paid over the period. Simply divide your account value by $1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then multiply the result by the number in the first line under the heading entitled “Expenses Paid During Period” to estimate the expenses you paid on your account during this period.

Hypothetical Example for Comparison Purposes

The second line for each share class in the following table provides information about hypothetical account values and hypothetical expenses based on the fund’s actual expense ratio and an assumed rate of return of 5% per year before expenses, which is not the fund’s actual return. The hypothetical account values and expenses may not be used to estimate the actual ending account balance or expenses you paid for the period. You may use this information to compare the ongoing costs of investing in the fund and other funds. To do so, compare this 5% hypothetical example with the 5% hypothetical examples that appear in the shareholder reports of the other funds.

Please note that the expenses shown in the table are meant to highlight your ongoing costs only and do not reflect any transactional costs, such as sales charges (loads). Therefore, the second line for each share class in the table is useful in comparing ongoing costs only, and will not help you determine the relative total costs of owning different funds. In addition, if these transactional costs were included, your costs would have been higher.

8

Expense Table – continued

Share Class		Annualized Expense Ratio		Beginning Account Value 5/01/12		Ending Account Value 10/31/12		Expenses Paid During Period (p) 5/01/12-10/31/12
A	Actual		1.32%		$1,000.00		$1,015.51		$6.69
	Hypothetical (h)		1.32%		$1,000.00		$1,018.50		$6.70
B	Actual		2.07%		$1,000.00		$1,011.00		$10.46
	Hypothetical (h)		2.07%		$1,000.00		$1,014.73		$10.48
C	Actual		2.06%		$1,000.00		$1,011.55		$10.42
	Hypothetical (h)		2.06%		$1,000.00		$1,014.78		$10.43
I	Actual		1.07%		$1,000.00		$1,016.54		$5.42
	Hypothetical (h)		1.07%		$1,000.00		$1,019.76		$5.43
R1	Actual		2.06%		$1,000.00		$1,011.57		$10.42
	Hypothetical (h)		2.06%		$1,000.00		$1,014.78		$10.43
R2	Actual		1.56%		$1,000.00		$1,013.65		$7.90
	Hypothetical (h)		1.56%		$1,000.00		$1,017.29		$7.91
R3	Actual		1.31%		$1,000.00		$1,015.53		$6.64
	Hypothetical (h)		1.31%		$1,000.00		$1,018.55		$6.65
R4	Actual		1.06%		$1,000.00		$1,016.54		$5.37
	Hypothetical (h)		1.06%		$1,000.00		$1,019.81		$5.38
R5 (formerly Class W)	Actual		1.13%		$1,000.00		$1,016.53		$5.73
	Hypothetical (h)		1.13%		$1,000.00		$1,019.46		$5.74

(h) 5% class return per year before expenses.

(p) Expenses paid are equal to each class’ annualized expense ratio, as shown above, multiplied by the average account value over the period, multiplied by the number of days in the period, divided by the number of days in the year. Expenses paid do not include any applicable sales charges (loads). If these transaction costs had been included, your costs would have been higher.

Expense Changes Impacting the Table

As further discussed in Note 5 in the Notes to Financial statements, the Class W shares were redesignated Class R5 on May 30, 2012 which resulted in changes to the fund’s fee agreements. Class R5 shares are generally available only to certain eligible retirement plans and to the funds distributed by MFD. Class R5 shares do not pay a 12b-1 distribution fee or sub-accounting costs. Additional changes to the fund’s fee arrangements occurred during the six month period as well. Had these fee changes been in effect throughout the entire six month period, the annualized expense ratios would have been 1.00% for Class R5; the actual expenses paid during the period would have been approximately $5.07 for Class R5; and the hypothetical expenses paid during the period would have been approximately $5.08 for Class R5. For further information about the fund’s fee arrangements and changes to those fee arrangements, please see Note 3 in the Notes to Financial Statements.

9

PORTFOLIO OF INVESTMENTS

10/31/12

The Portfolio of Investments is a complete list of all securities owned by your fund. It is categorized by broad-based asset classes.

Common Stocks - 99.4%
Issuer	Shares/Par		Value ($)
Airlines - 5.1%
Copa Holdings S.A., “A”		46,810	$	4,344,903
Spirit Airlines, Inc. (a)		187,700		3,294,135
			$	7,639,038
Automotive - 4.8%
Delphi Automotive PLC (a)		140,310	$	4,411,346
General Motors Co. (a)		110,090		2,807,295
			$	7,218,641
Business Services - 2.5%
FleetCor Technologies, Inc. (a)		79,360	$	3,762,458
Cable TV - 6.1%
Comcast Corp., “Special A”		119,020	$	4,337,089
Time Warner Cable, Inc.		48,460		4,802,871
			$	9,139,960
Computer Software - 5.7%
Microsoft Corp.		107,900	$	3,078,927
SolarWinds, Inc. (a)		108,190		5,473,332
			$	8,552,259
Computer Software - Systems - 2.9%
Apple, Inc.		7,160	$	4,260,916
Consumer Products - 2.3%
Nu Skin Enterprises, Inc., “A”		72,660	$	3,438,998
Energy - Independent - 2.4%
Energy XXI (Bermuda) Ltd.		109,109	$	3,611,508
Energy - Integrated - 2.4%
Chevron Corp.		32,830	$	3,618,194
Food & Beverages - 5.1%
Coca-Cola Enterprises, Inc.		111,780	$	3,514,363
Ingredion, Inc.		65,940		4,052,672
			$	7,567,035

10

Portfolio of Investments – continued

Issuer	Shares/Par		Value ($)
Common Stocks - continued
Food & Drug Stores - 2.5%
Kroger Co.		145,860	$	3,678,589
Health Maintenance Organizations - 5.0%
Aetna, Inc.		91,020	$	3,977,574
UnitedHealth Group, Inc.		61,490		3,443,440
			$	7,421,014
Insurance - 16.1%
Aflac, Inc.		48,960	$	2,437,229
American International Group, Inc. (a)		105,380		3,680,923
Everest Re Group Ltd.		35,030		3,890,082
Genworth Financial, Inc. (a)		326,560		1,946,298
Hartford Financial Services Group, Inc.		143,220		3,109,306
MetLife, Inc.		76,360		2,710,016
Prudential Financial, Inc.		47,060		2,684,773
Validus Holdings Ltd.		101,220		3,623,676
			$	24,082,303
Leisure & Toys - 2.2%
Activision Blizzard, Inc.		296,000	$	3,223,440
Machinery & Tools - 4.8%
Allison Transmission Holdings, Inc.		190,710	$	3,850,435
Regal Beloit Corp.		51,810		3,376,976
			$	7,227,411
Major Banks - 2.2%
JPMorgan Chase & Co.		77,240	$	3,219,363
Medical & Health Technology & Services - 2.3%
HCA Holdings, Inc.		121,510	$	3,452,099
Metals & Mining - 1.6%
Cliffs Natural Resources, Inc.		66,470	$	2,410,867
Other Banks & Diversified Financials - 6.5%
CapitalSource, Inc.		483,080	$	3,821,163
Discover Financial Services		143,240		5,872,840
			$	9,694,003
Pharmaceuticals - 2.9%
Pfizer, Inc.		171,110	$	4,255,506

11

Portfolio of Investments – continued

Issuer	Shares/Par		Value ($)
Common Stocks - continued
Specialty Stores - 3.6%
ANN INC. (a)		91,690	$	3,223,820
Zumiez, Inc. (a)		87,490		2,214,372
			$	5,438,192
Tobacco - 3.6%
Lorillard, Inc.		30,390	$	3,525,544
Schweitzer-Mauduit International, Inc.		52,880		1,852,386
			$	5,377,930
Trucking - 2.5%
Atlas Air Worldwide Holdings, Inc. (a)		67,130	$	3,691,479
Utilities - Electric Power - 4.3%
AES Corp.		274,060	$	2,863,927
CenterPoint Energy, Inc.		165,240		3,580,751
			$	6,444,678
Total Common Stocks (Identified Cost, $135,961,676)			$	148,425,881
Money Market Funds - 0.5%
MFS Institutional Money Market Portfolio, 0.16%, at Cost and Net Asset Value (v)		807,942	$	807,942
Total Investments (Identified Cost, $136,769,618)			$	149,233,823
Other Assets, Less Liabilities - 0.1%				100,973
Net Assets - 100.0%			$	149,334,796

(a) Non-income producing security.

(v) Underlying affiliated fund that is available only to investment companies managed by MFS. The rate quoted for the MFS Institutional Money Market Portfolio is the annualized seven-day yield of the fund at period end.

The following abbreviations are used in this report and are defined:

PLC Public Limited Company

See Notes to Financial Statements

12

Financial Statements

STATEMENT OF ASSETS AND LIABILITIES

At 10/31/12

This statement represents your fund’s balance sheet, which details the assets and liabilities comprising the total value of the fund.

Assets
Investments-
Non-affiliated issuers, at value (identified cost, $135,961,676)	$148,425,881
Underlying affiliated funds, at cost and value	807,942
Total investments, at value (identified cost, $136,769,618)	$149,233,823
Cash	36,500
Receivables for
Fund shares sold	101,029
Dividends	314,738
Total assets	$149,686,090
Liabilities
Payable for fund shares reacquired	$192,420
Payable to affiliates
Investment adviser	9,341
Shareholder servicing costs	86,651
Distribution and service fees	5,117
Payable for independent Trustees’ compensation	101
Accrued expenses and other liabilities	57,664
Total liabilities	$351,294
Net assets	$149,334,796
Net assets consist of
Paid-in capital	$243,018,757
Unrealized appreciation (depreciation) on investments	12,464,205
Accumulated net realized gain (loss) on investments	(106,995,249	)
Undistributed net investment income	847,083
Net assets	$149,334,796
Shares of beneficial interest outstanding	7,931,225

13

Statement of Assets and Liabilities – continued

	Net assets		Shares outstanding		Net asset value per share (a)
Class A		$87,130,479		4,588,702		$18.99
Class B		10,056,067		547,047		18.38
Class C		31,014,141		1,685,612		18.40
Class I		14,921,383		783,359		19.05
Class R1		101,003		5,503		18.36
Class R2		117,417		6,326		18.56
Class R3		120,291		6,345		18.96
Class R4		5,763,955		302,561		19.05
Class R5 (formerly Class W)		110,060		5,770		19.07

(a) Maximum offering price per share was equal to the net asset value per share for all share classes, except for Class A, for which the maximum offering price per share was $20.15 [100 / 94.25 x $18.99]. On sales of $50,000 or more, the maximum offering price of Class A shares is reduced. A contingent deferred sales charge may be imposed on redemptions of Class A, Class B, and Class C shares. Redemption price per share was equal to the net asset value per share for Classes I, R1, R2, R3, R4, and R5.

Shares outstanding are rounded for presentation purposes.

See Notes to Financial Statements

14

Financial Statements

STATEMENT OF OPERATIONS

Year ended 10/31/12

This statement describes how much your fund earned in investment income and accrued in expenses. It also describes any gains and/or losses generated by fund operations.

Net investment income
Income
Dividends	$3,220,197
Interest	9,630
Dividends from underlying affiliated funds	1,238
Total investment income	$3,231,065
Expenses
Management fee	$1,131,313
Distribution and service fees	645,238
Shareholder servicing costs	241,032
Administrative services fee	32,247
Independent Trustees’ compensation	5,418
Custodian fee	23,145
Shareholder communications	32,549
Audit and tax fees	43,878
Legal fees	2,097
Registration fees	114,988
Miscellaneous	21,354
Total expenses	$2,293,259
Fees paid indirectly	(1	)
Reduction of expenses by investment adviser	(539	)
Net expenses	$2,292,719
Net investment income	$938,346
Realized and unrealized gain (loss) on investments
Realized gain (loss) on investments (identified cost basis)	$11,140,575
Change in unrealized appreciation (depreciation) on investments	$9,161,607
Net realized and unrealized gain (loss) on investments	$20,302,182
Change in net assets from operations	$21,240,528

See Notes to Financial Statements

15

Financial Statements

STATEMENTS OF CHANGES IN NET ASSETS

These statements describe the increases and/or decreases in net assets resulting from operations, any distributions, and any shareholder transactions.

	Years ended 10/31
	2012			2011
Change in net assets
From operations
Net investment income		$938,346			$1,869,194
Net realized gain (loss) on investments		11,140,575			27,025,101
Net unrealized gain (loss) on investments		9,161,607			(23,293,015	)
Change in net assets from operations		$21,240,528			$5,601,280
Distributions declared to shareholders
From net investment income		$(1,580,018	)		$(1,050,009	)
Change in net assets from fund share transactions		$(22,800,355	)		$(6,965,918	)
Total change in net assets		$(3,139,845	)		$(2,414,647	)
Net assets
At beginning of period		152,474,641			154,889,288
At end of period (including undistributed net investment income of $847,083 and $1,488,755, respectively)		$149,334,796			$152,474,641

See Notes to Financial Statements

16

Financial Statements

FINANCIAL HIGHLIGHTS

The financial highlights table is intended to help you understand the fund’s financial performance for the past 5 years (or life of a particular share class, if shorter). Certain information reflects financial results for a single fund share. The total returns in the table represent the rate by which an investor would have earned (or lost) on an investment in the fund share class (assuming reinvestment of all distributions) held for the entire period.

Class A	Years ended 10/31
	2012			2011			2010			2009		2008
Net asset value, beginning of period		$16.66			$16.01			$12.62			$12.40		$20.02
Income (loss) from investment operations
Net investment income (d)		$0.14			$0.21			$0.08			$0.04		$0.02
Net realized and unrealized gain (loss) on investments and foreign currency		2.40			0.57			3.34			0.18		(7.64	)
Total from investment operations		$2.54			$0.78			$3.42			$0.22		$(7.62	)
Less distributions declared to shareholders
From net investment income		$(0.21	)		$(0.13	)		$(0.03	)		$—		$—
Net asset value, end of period (x)		$18.99			$16.66			$16.01			$12.62		$12.40
Total return (%) (r)(s)(t)(x)		15.50			4.88			27.15			1.77		(38.06	)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.34			1.32			1.37			1.41		1.38
Expenses after expense reductions (f)		1.34			1.32			1.37			1.39		1.38
Net investment income		0.80			1.23			0.59			0.34		0.13
Portfolio turnover		123			154			191			211		196
Net assets at end of period (000 omitted)		$87,130			$91,778			$90,409			$137,360		$236,816

See Notes to Financial Statements

17

Financial Highlights – continued

Class B	Years ended 10/31
	2012			2011			2010			2009			2008
Net asset value, beginning of period		$16.12			$15.50			$12.28			$12.16			$19.75
Income (loss) from investment operations
Net investment income (loss) (d)		$0.01			$0.08			$(0.02	)		$(0.04	)		$(0.09	)
Net realized and unrealized gain (loss) on investments and foreign currency		2.32			0.56			3.24			0.16			(7.50	)
Total from investment operations		$2.33			$0.64			$3.22			$0.12			$(7.59	)
Less distributions declared to shareholders
From net investment income		$(0.07	)		$(0.02	)		$—			$—			$—
Net asset value, end of period (x)		$18.38			$16.12			$15.50			$12.28			$12.16
Total return (%) (r)(s)(t)(x)		14.56			4.14			26.22			0.99			(38.43	)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		2.09			2.07			2.12			2.12			2.03
Expenses after expense reductions (f)		2.09			2.07			2.12			2.10			2.03
Net investment income (loss)		0.05			0.51			(0.16	)		(0.39	)		(0.53	)
Portfolio turnover		123			154			191			211			196
Net assets at end of period (000 omitted)		$10,056			$10,419			$11,825			$12,028			$15,029

Class C	Years ended 10/31
	2012			2011			2010			2009			2008
Net asset value, beginning of period		$16.13			$15.51			$12.29			$12.16			$19.76
Income (loss) from investment operations
Net investment income (loss) (d)		$0.01			$0.08			$(0.02	)		$(0.04	)		$(0.09	)
Net realized and unrealized gain (loss) on investments and foreign currency		2.34			0.55			3.24			0.17			(7.51	)
Total from investment operations		$2.35			$0.63			$3.22			$0.13			$(7.60	)
Less distributions declared to shareholders
From net investment income		$(0.08	)		$(0.01	)		$—			$—			$—
Net asset value, end of period (x)		$18.40			$16.13			$15.51			$12.29			$12.16
Total return (%) (r)(s)(t)(x)		14.63			4.09			26.20			1.07			(38.46	)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		2.09			2.07			2.12			2.12			2.03
Expenses after expense reductions (f)		2.09			2.07			2.12			2.10			2.03
Net investment income (loss)		0.06			0.49			(0.16	)		(0.39	)		(0.53	)
Portfolio turnover		123			154			191			211			196
Net assets at end of period (000 omitted)		$31,014			$32,005			$34,189			$46,261			$61,857

See Notes to Financial Statements

18

Financial Highlights – continued

Class I	Years ended 10/31
	2012			2011 (i)
Net asset value, beginning of period		$16.72			$17.79
Income (loss) from investment operations
Net investment income (d)		$0.17			$0.05
Net realized and unrealized gain (loss) on investments and foreign currency		2.42			(1.12	)(g)
Total from investment operations		$2.59			$(1.07	)
Less distributions declared to shareholders
From net investment income		$(0.26	)		$—
Net asset value, end of period (x)		$19.05			$16.72
Total return (%) (r)(s)(x)		15.79			(6.01	)(n)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.08			0.99	(a)
Expenses after expense reductions (f)		1.08			0.99	(a)
Net investment income		0.97			0.46	(a)
Portfolio turnover		123			154
Net assets at end of period (000 omitted)		$14,921			$7,440

Class R1	Years ended 10/31
	2012			2011			2010			2009			2008 (i)
Net asset value, beginning of period		$16.11			$15.51			$12.29			$12.16			$18.32
Income (loss) from investment operations
Net investment income (loss) (d)		$0.01			$0.08			$(0.02	)		$(0.05	)		$(0.04	)
Net realized and unrealized gain (loss) on investments and foreign currency		2.33			0.55			3.24			0.18			(6.12	)(g)
Total from investment operations		$2.34			$0.63			$3.22			$0.13			$(6.16	)
Less distributions declared to shareholders
From net investment income		$(0.09	)		$(0.03	)		$—			$—			$—
Net asset value, end of period (x)		$18.36			$16.11			$15.51			$12.29			$12.16
Total return (%) (r)(s)(x)		14.66			4.08			26.20			1.07			(33.62	)(n)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		2.09			2.06			2.12			2.12			2.03	(a)
Expenses after expense reductions (f)		2.09			2.06			2.12			2.10			2.03	(a)
Net investment income (loss)		0.06			0.47			(0.15	)		(0.41	)		(0.48	)(a)
Portfolio turnover		123			154			191			211			196
Net assets at end of period (000 omitted)		$101			$92			$85			$67			$66

See Notes to Financial Statements

19

Financial Highlights – continued

Class R2	Years ended 10/31
	2012			2011			2010			2009		2008 (i)
Net asset value, beginning of period		$16.30			$15.67			$12.38			$12.19		$18.32
Income (loss) from investment operations
Net investment income (d)		$0.10			$0.16			$0.05			$0.01		$0.00	(w)
Net realized and unrealized gain (loss) on investments and foreign currency		2.34			0.57			3.27			0.18		(6.13	)(g)
Total from investment operations		$2.44			$0.73			$3.32			$0.19		$(6.13	)
Less distributions declared to shareholders
From net investment income		$(0.18	)		$(0.10	)		$(0.03	)		$—		$—
Net asset value, end of period (x)		$18.56			$16.30			$15.67			$12.38		$12.19
Total return (%) (r)(s)(x)		15.16			4.67			26.82			1.56		(33.46	)(n)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.59			1.56			1.62			1.62		1.53	(a)
Expenses after expense reductions (f)		1.59			1.56			1.62			1.60		1.52	(a)
Net investment income		0.55			0.94			0.35			0.08		0.02	(a)
Portfolio turnover		123			154			191			211		196
Net assets at end of period (000 omitted)		$117			$99			$86			$68		$67
Class R3	Years ended 10/31
	2012			2011			2010			2009		2008 (i)
Net asset value, beginning of period		$16.65			$15.99			$12.63			$12.41		$18.62
Income (loss) from investment operations
Net investment income (d)		$0.14			$0.20			$0.08			$0.04		$0.02
Net realized and unrealized gain (loss) on investments and foreign currency		2.39			0.60			3.33			0.18		(6.23	)(g)
Total from investment operations		$2.53			$0.80			$3.41			$0.22		$(6.21	)
Less distributions declared to shareholders
From net investment income		$(0.22	)		$(0.14	)		$(0.05	)		$—		$—
Net asset value, end of period (x)		$18.96			$16.65			$15.99			$12.63		$12.41
Total return (%) (r)(s)(x)		15.44			4.98			27.11			1.77		(33.35	)(n)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.34			1.31			1.37			1.37		1.27	(a)
Expenses after expense reductions (f)		1.34			1.31			1.37			1.35		1.27	(a)
Net investment income		0.80			1.20			0.60			0.33		0.28	(a)
Portfolio turnover		123			154			191			211		196
Net assets at end of period (000 omitted)		$120			$102			$86			$68		$67

See Notes to Financial Statements

20

Financial Highlights – continued

Class R4	Years ended 10/31
	2012			2011			2010			2009		2008 (i)
Net asset value, beginning of period		$16.73			$16.07			$12.68			$12.43		$18.62
Income (loss) from investment operations
Net investment income (d)		$0.18			$0.25			$0.10			$0.07		$0.04
Net realized and unrealized gain (loss) on investments and foreign currency		2.40			0.58			3.37			0.18		(6.23	)(g)
Total from investment operations		$2.58			$0.83			$3.47			$0.25		$(6.19	)
Less distributions declared to shareholders
From net investment income		$(0.26	)		$(0.17	)		$(0.08	)		$—		$—
Net asset value, end of period (x)		$19.05			$16.73			$16.07			$12.68		$12.43
Total return (%) (r)(s)(x)		15.72			5.18			27.52			2.01		(33.24	)(n)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.09			1.07			1.10			1.12		1.03	(a)
Expenses after expense reductions (f)		1.09			1.07			1.10			1.11		1.03	(a)
Net investment income		1.04			1.48			0.73			0.57		0.57	(a)
Portfolio turnover		123			154			191			211		196
Net assets at end of period (000 omitted)		$5,764			$4,985			$4,886			$1,258		$1,069
Class R5 (formerly Class W) (y)	Years ended 10/31
	2012			2011			2010			2009		2008 (i)
Net asset value, beginning of period		$16.70			$16.04			$12.67			$12.42		$17.96
Income (loss) from investment operations
Net investment income (d)		$0.21			$0.23			$0.10			$0.05		$0.03
Net realized and unrealized gain (loss) on investments and foreign currency		2.37			0.59			3.35			0.20		(5.57	)(g)
Total from investment operations		$2.58			$0.82			$3.45			$0.25		$(5.54	)
Less distributions declared to shareholders
From net investment income		$(0.21	)		$(0.16	)		$(0.08	)		$—		$—
Net asset value, end of period (x)		$19.07			$16.70			$16.04			$12.67		$12.42
Total return (%) (r)(s)(x)		15.68			5.10			27.34			2.01		(30.85	)(n)
Ratios (%) (to average net assets) and Supplemental data:
Expenses before expense reductions (f)		1.22			1.16			1.22			1.20		1.13	(a)
Expenses after expense reductions (f)		1.22			1.16			1.22			1.19		1.12	(a)
Net investment income		1.19			1.32			0.72			0.36		0.30	(a)
Portfolio turnover		123			154			191			211		196
Net assets at end of period (000 omitted)		$110			$5,556			$13,324			$15,824		$1,430

See Notes to Financial Statements

21

Financial Highlights – continued

(a) Annualized.

(d) Per share data is based on average shares outstanding.

(f) Ratios do not reflect reductions from fees paid indirectly, if applicable.

(g) The per share amount varies from the net realized and unrealized gain/loss for the period because of the timing of sales of fund shares and the per share amount of realized and unrealized gains and losses at such time.

(i) For the period from the class’ inception February 28, 2011 (Class I), March 3, 2008 (Class R5), and May 1, 2008 (Classes R1, R2, R3, and R4) through the stated period end.

(n) Not annualized.

(r) Certain expenses have been reduced without which performance would have been lower.

(s) From time to time the fund may receive proceeds from litigation settlements, without which performance would be lower.

(t) Total returns do not include any applicable sales charges.

(w) Per share amount was less than $0.01.

(x) The net asset values per share and total returns have been calculated on net assets which include adjustments made in accordance with U.S. generally accepted accounting principles required at period end for financial reporting purposes.

(y) As further discussed in Note 5 in the Notes to Financial Statements, on May 10, 2012, sales of Class W shares (including exchanges) were suspended. On May 11, 2012, certain Class W shares were automatically converted to Class I shares. Shareholders of certain Class W shares became shareholders of Class I and received Class I shares with a total net asset value equal to their Class W shares at the time of the conversion. On May 30, 2012, remaining Class W shares, which represented MFS seed money, were redesignated Class R5. Class R5 shares are generally available only to certain eligible retirement plans and to funds distributed by MFD. Class R5 shares do not pay a 12b-1 distribution fee or sub-accounting costs. On June 1, 2012, Class R5 shares were offered for sale to the public. For further information about the fund’s fee arrangements and changes to those fee arrangements, please see Note 3 in the Notes to Financial Statements.

See Notes to Financial Statements

22

NOTES TO FINANCIAL STATEMENTS

(1) Business and Organization

MFS Equity Opportunities Fund (the fund) is a series of MFS Series Trust XII (the trust). The trust is organized as a Massachusetts business trust and is registered under the Investment Company Act of 1940, as amended, as an open-end management investment company.

(2) Significant Accounting Policies

General – The preparation of financial statements in conformity with U.S. 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. In the preparation of these financial statements, management has evaluated subsequent events occurring after the date of the fund’s Statement of Assets and Liabilities through the date that the financial statements were issued.

In this reporting period the fund adopted FASB Accounting Standards Update 2011-04, Fair Value Measurement (Topic 820) – Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S. GAAP and IFRSs (“ASU 2011-04”). ASU 2011-04 seeks to improve the comparability of fair value measurements as presented and disclosed in financial statements prepared in accordance with U.S. GAAP and International Financial Reporting Standards (IFRS) by providing common requirements for fair value measurement and disclosure.

In December 2011, the Financial Accounting Standards Board issued Accounting Standards Update 2011-11, Balance Sheet (Topic 210) – Disclosures about Offsetting Assets and Liabilities (“ASU 2011-11”). Effective for annual reporting periods beginning on or after January 1, 2013 and interim periods within those annual periods, ASU 2011-11 is intended to enhance disclosure requirements on the offsetting of financial assets and liabilities. Although still evaluating the potential impacts of ASU 2011-11 to the fund, management expects that the impact of the fund’s adoption will be limited to additional financial statement disclosures.

Investment Valuations – Equity securities, including restricted equity securities, are generally valued at the last sale or official closing price as provided by a third-party pricing service on the market or exchange on which they are primarily traded. Equity securities, for which there were no sales reported that day, are generally valued at the last quoted daily bid quotation as provided by a third-party pricing service on the market or exchange on which such securities are primarily traded. Short-term instruments with a maturity at issuance of 60 days or less generally are valued at amortized cost, which approximates market value. Open-end investment companies are generally valued at net asset value per share. Securities and other assets generally valued on the basis of information from a third-party pricing service may also be valued at a broker/dealer bid quotation. Values obtained from third-party pricing services can utilize both transaction data and market information such as yield, quality, coupon rate, maturity, type of issue, trading characteristics, and other market data. The values

23

Notes to Financial Statements – continued

of foreign securities and other assets and liabilities expressed in foreign currencies are converted to U.S. dollars using the mean of bid and asked prices for rates provided by a third-party pricing service.

The Board of Trustees has delegated primary responsibility for determining or causing to be determined the value of the fund’s investments (including any fair valuation) to the adviser pursuant to valuation policies and procedures approved by the Board. If the adviser determines that reliable market quotations are not readily available, investments are valued at fair value as determined in good faith by the adviser in accordance with such procedures under the oversight of the Board of Trustees. Under the fund’s valuation policies and procedures, market quotations are not considered to be readily available for most types of debt instruments and floating rate loans and many types of derivatives. These investments are generally valued at fair value based on information from third-party pricing services. In addition, investments may be valued at fair value if the adviser determines that an investment’s value has been materially affected by events occurring after the close of the exchange or market on which the investment is principally traded (such as foreign exchange or market) and prior to the determination of the fund’s net asset value, or after the halting of trading of a specific security where trading does not resume prior to the close of the exchange or market on which the security is principally traded. Events that occur on a frequent basis after foreign markets close (such as developments in foreign markets and significant movements in the U.S. markets) and prior to the determination of the fund’s net asset value may be deemed to have a material effect on the value of securities traded in foreign markets. Accordingly, the fund’s foreign equity securities may often be valued at fair value. The adviser generally relies on third-party pricing services or other information (such as the correlation with price movements of similar securities in the same or other markets; the type, cost and investment characteristics of the security; the business and financial condition of the issuer; and trading and other market data) to assist in determining whether to fair value and at what value to fair value an investment. The value of an investment for purposes of calculating the fund’s net asset value can differ depending on the source and method used to determine value. When fair valuation is used, the value of an investment used to determine the fund’s net asset value may differ from quoted or published prices for the same investment. There can be no assurance that the fund could obtain the fair value assigned to an investment if it were to sell the investment at the same time at which the fund determines its net asset value per share.

Various inputs are used in determining the value of the fund’s assets or liabilities. These inputs are categorized into three broad levels. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, an investment’s level within the fair value hierarchy is based on the lowest level of input that is significant to the fair value measurement. The fund’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment, and considers factors specific to the investment. Level 1 includes unadjusted quoted prices in active markets for identical assets or liabilities. Level 2 includes other significant observable market-based inputs (including quoted prices for similar securities, interest rates, prepayment speed, and credit risk). Level 3 includes unobservable inputs, which may include the adviser’s own assumptions in determining

24

Notes to Financial Statements – continued

the fair value of investments. The following is a summary of the levels used as of October 31, 2012 in valuing the fund’s assets or liabilities:

Investments at Value	Level 1		Level 2		Level 3		Total
Equity Securities		$148,425,881		$—		$—		$148,425,881
Mutual Funds		807,942		—		—		807,942
Total Investments		$149,233,823		$—		$—		$149,233,823

For further information regarding security characteristics, see the Portfolio of Investments.

Security Loans – State Street Bank and Trust Company (“State Street”), as lending agent, loans the securities of the fund to certain qualified institutions (the “Borrowers”) approved by the fund. The loans are collateralized by cash and/or U.S. Treasury and federal agency obligations in an amount typically at least equal to the market value of the securities loaned. The market value of the loaned securities is determined at the close of business of the fund and any additional required collateral is delivered to the fund on the next business day. State Street provides the fund with indemnification against Borrower default. The fund bears the risk of loss with respect to the investment of cash collateral. On loans collateralized by cash, the cash collateral is invested in a money market fund or short-term securities. A portion of the income generated upon investment of the collateral is remitted to the Borrowers, and the remainder is allocated between the fund and the lending agent. On loans collateralized by U.S. Treasury and/or federal agency obligations, a fee is received from the Borrower, and is allocated between the fund and the lending agent. Income from securities lending is included in “Interest” income on the Statement of Operations. The dividend and interest income earned on the securities loaned is accounted for in the same manner as other dividend and interest income.

Indemnifications – Under the fund’s organizational documents, its officers and Trustees may be indemnified against certain liabilities and expenses arising out of the performance of their duties to the fund. Additionally, in the normal course of business, the fund enters into agreements with service providers that may contain indemnification clauses. The fund’s maximum exposure under these agreements is unknown as this would involve future claims that may be made against the fund that have not yet occurred.

Investment Transactions and Income – Investment transactions are recorded on the trade date. Interest income is recorded on the accrual basis. Dividends received in cash are recorded on the ex-dividend date. Certain dividends from foreign securities will be recorded when the fund is informed of the dividend if such information is obtained subsequent to the ex-dividend date. Dividend and interest payments received in additional securities are recorded on the ex-dividend or ex-interest date in an amount equal to the value of the security on such date.

The fund may receive proceeds from litigation settlements. Any proceeds received from litigation involving portfolio holdings are reflected in the Statement of Operations in realized gain/loss if the security has been disposed of by the fund or in unrealized gain/loss if the security is still held by the fund. Any other proceeds from litigation not related to portfolio holdings are reflected as other income in the Statement of Operations.

25

Notes to Financial Statements – continued

Fees Paid Indirectly – The fund’s custody fee may be reduced according to an arrangement that measures the value of cash deposited with the custodian by the fund. This amount, for the year ended October 31, 2012, is shown as a reduction of total expenses on the Statement of Operations.

Tax Matters and Distributions – The fund intends to qualify as a regulated investment company, as defined under Subchapter M of the Internal Revenue Code, and to distribute all of its taxable income, including realized capital gains. As a result, no provision for federal income tax is required. The fund’s federal tax returns, when filed, will remain subject to examination by the Internal Revenue Service for a three year period.

Distributions to shareholders are recorded on the ex-dividend date. Income and capital gain distributions are determined in accordance with income tax regulations, which may differ from U.S. generally accepted accounting principles. Certain capital accounts in the financial statements are periodically adjusted for permanent differences in order to reflect their tax character. These adjustments have no impact on net assets or net asset value per share. Temporary differences which arise from recognizing certain items of income, expense, gain or loss in different periods for financial statement and tax purposes will reverse at some time in the future. Distributions in excess of net investment income or net realized gains are temporary overdistributions for financial statement purposes resulting from differences in the recognition or classification of income or distributions for financial statement and tax purposes.

During the year ended October 31, 2012, there were no significant adjustments due to differences between book and tax accounting.

The tax character of distributions declared to shareholders for the last two fiscal years is as follows:

	10/31/12		10/31/11
Ordinary income (including any short-term capital gains)		$1,580,018		$1,050,009

The federal tax cost and the tax basis components of distributable earnings were as follows:

As of 10/31/12
Cost of investments	$136,807,294
Gross appreciation	19,109,875
Gross depreciation	(6,683,346	)
Net unrealized appreciation (depreciation)	$12,426,529
Undistributed ordinary income	847,083
Capital loss carryforwards	(106,957,573	)

Under the Regulated Investment Company Modernization Act of 2010 (the “Act”), net capital losses recognized after October 31, 2011 may be carried forward indefinitely, and their character is retained as short-term and/or long-term losses. Previously, net capital losses were carried forward for eight years and treated as short-term losses. As a transition rule, the Act requires that post-enactment net capital losses be used before pre-enactment net capital losses.

26

Notes to Financial Statements – continued

As of October 31, 2012, the fund had capital loss carryforwards available to offset future realized gains. Such losses expire as follows:

Pre-enactment losses:
10/31/16	$(33,646,696	)
10/31/17	(73,310,877	)
Total	$(106,957,573	)

Multiple Classes of Shares of Beneficial Interest – The fund offers multiple classes of shares, which differ in their respective distribution and service fees. The fund’s income, realized and unrealized gain (loss), and common expenses are allocated to shareholders based on the daily net assets of each class. Dividends are declared separately for each class. Differences in per share dividend rates are generally due to differences in separate class expenses. Class B shares will convert to Class A shares approximately eight years after purchase. The fund’s distributions declared to shareholders as reported on the Statements of Changes in Net Assets are presented by class as follows:

	From net investment income
	Year ended 10/31/12		Year ended 10/31/11
Class A		$1,139,585		$799,464
Class B		46,998		16,704
Class C		146,868		31,156
Class I		99,978		—
Class R1		532		179
Class R2		1,072		561
Class R3		1,334		741
Class R4		76,563		59,880
Class R5 (formerly Class W)		67,088		141,324
Total		$1,580,018		$1,050,009

On May 30, 2012, Class W shares were redesignated Class R5. See Note 5 for additional information.

(3) Transactions with Affiliates

Investment Adviser – The fund has an investment advisory agreement with MFS to provide overall investment management and related administrative services and facilities to the fund.

The management fee is computed daily and paid monthly at the following annual rates:

First $1 billion of average daily net assets	0.75	%
Next $1.5 billion of average daily net assets	0.65	%
Next $2.5 billion of average daily net assets	0.60	%
Average daily net assets in excess of $5 billion	0.50	%

The management fee incurred for the year ended October 31, 2012 was equivalent to an annual effective rate of 0.75% of the fund’s average daily net assets.

27

Notes to Financial Statements – continued

The investment adviser has agreed in writing to pay a portion of the fund’s total annual operating expenses, exclusive of interest, taxes, extraordinary expenses, brokerage and transaction costs, and investment-related expenses, such that total annual fund operating expenses do not exceed the following rates annually of each class’ average daily net assets.

Classes
A	B		C		I		R1		R2		R3		R4		R5
1.40%		2.15%		2.15%		1.15%		2.15%		1.65%		1.40%		1.15%		1.09% (a	)

(a) Prior to the redesignation of Class W shares to Class R5 shares on May 30, 2012, the investment adviser had agreed in writing to pay a portion of the fund’s total annual operating expenses, exclusive of interest, taxes, extraordinary expenses, brokerage and transaction costs, and investment-related expenses, such that total annual operating expense did not exceed 1.25% of average daily net assets for Class W shares.

This written agreement will continue until modified by the fund’s Board of Trustees, but such agreement will continue at least until February 28, 2014. For the year ended October 31, 2012 the fund’s actual operating expenses did not exceed the limit and therefore, the investment adviser did not pay any portion of the fund’s expenses related to this agreement.

Distributor – MFS Fund Distributors, Inc. (MFD), a wholly-owned subsidiary of MFS, as distributor, received $25,508 for the year ended October 31, 2012, as its portion of the initial sales charge on sales of Class A shares of the fund.

The Board of Trustees has adopted a distribution plan for certain class shares pursuant to Rule 12b-1 of the Investment Company Act of 1940.

The fund’s distribution plan provides that the fund will pay MFD for services provided by MFD and financial intermediaries in connection with the distribution and servicing of certain share classes. One component of the plan is a distribution fee paid to MFD and another component of the plan is a service fee paid to MFD. MFD may subsequently pay all, or a portion, of the distribution and/or service fees to financial intermediaries.

Distribution Plan Fee Table:

	Distribution Fee Rate (d)		Service Fee Rate (d)		Total Distribution Plan (d)		Annual Effective Rate (e)		Distribution and Service Fee
Class A		—		0.25%		0.25%		0.25%		$224,158
Class B		0.75%		0.25%		1.00%		1.00%		102,764
Class C		0.75%		0.25%		1.00%		1.00%		314,143
Class R1		0.75%		0.25%		1.00%		1.00%		956
Class R2		0.25%		0.25%		0.50%		0.50%		540
Class R3		—		0.25%		0.25%		0.25%		277
Class R5 (formerly Class W)		—		—		—		0.10%		2,400
Total Distribution and Service Fees										$645,238

(d) In accordance with the distribution plan for certain classes, the fund pays distribution and/or service fees equal to these annual percentage rates of each class’ average daily net assets. The distribution and service fee rates disclosed by class represent the current rates in effect at the end of the reporting period.

28

Notes to Financial Statements – continued

(e) The annual effective rates represent actual fees incurred under the distribution plan for the year ended October 31, 2012 based on each class’ average daily net assets. Effective May 30, 2012, Class W shares were redesignated Class R5 shares. Effective May 31, 2012, the 0.10% Class W distribution fee was eliminated.

Certain Class A shares are subject to a contingent deferred sales charge (CDSC) in the event of a shareholder redemption within 18 months of purchase for shares purchased on or after August 1, 2012, and within 24 months of purchase for shares purchased prior to August 1, 2012. Class C shares are subject to a CDSC in the event of a shareholder redemption within 12 months of purchase. Class B shares are subject to a CDSC in the event of a shareholder redemption within six years of purchase. All contingent deferred sales charges are paid to MFD and during the year ended October 31, 2012, were as follows:

	Amount
Class A		$65
Class B		20,802
Class C		1,749

Shareholder Servicing Agent – MFS Service Center, Inc. (MFSC), a wholly-owned subsidiary of MFS, receives a fee from the fund for its services as shareholder servicing agent calculated as a percentage of the average daily net assets of the fund as determined periodically under the supervision of the fund’s Board of Trustees. For the year ended October 31, 2012, the fee was $52,902, which equated to 0.0351% annually of the fund’s average daily net assets. MFSC also receives payment from the fund for out-of-pocket expenses, sub-accounting and other shareholder servicing costs which may be paid to affiliated and unaffiliated service providers. For the year ended October 31, 2012, these out-of-pocket expenses, sub-accounting and other shareholder servicing costs amounted to $188,130. Effective with the redesignation of Class W to Class R5 on May 30, 2012 (as discussed in Note 5), Class R5 shares do not incur sub-accounting fees.

Administrator – MFS provides certain financial, legal, shareholder communications, compliance, and other administrative services to the fund. Under an administrative services agreement, the fund partially reimburses MFS the costs incurred to provide these services. The fund is charged an annual fixed amount of $17,500 plus a fee based on average daily net assets. The administrative services fee incurred for the year ended October 31, 2012 was equivalent to an annual effective rate of 0.0214% of the fund’s average daily net assets.

Trustees’ and Officers’ Compensation – The fund pays compensation to independent Trustees in the form of a retainer, attendance fees, and additional compensation to Board and Committee chairpersons. The fund does not pay compensation directly to Trustees or officers of the fund who are also officers of the investment adviser, all of whom receive remuneration for their services to the fund from MFS. Certain officers and Trustees of the fund are officers or directors of MFS, MFD, and MFSC.

Other – This fund and certain other funds managed by MFS (the funds) have entered into services agreements (the Agreements) which provide for payment of fees by the funds to Tarantino LLC and Griffin Compliance LLC in return for the provision of

29

Notes to Financial Statements – continued

services of an Independent Chief Compliance Officer (ICCO) and Assistant ICCO, respectively, for the funds. The ICCO and Assistant ICCO are officers of the funds and the sole members of Tarantino LLC and Griffin Compliance LLC, respectively. The funds can terminate the Agreements with Tarantino LLC and Griffin Compliance LLC at any time under the terms of the Agreements. For the year ended October 31, 2012, the aggregate fees paid by the fund to Tarantino LLC and Griffin Compliance LLC were $1,362 and are included in “Miscellaneous” expense on the Statement of Operations. MFS has agreed to reimburse the fund for a portion of the payments made by the fund in the amount of $539, which is shown as a reduction of total expenses in the Statement of Operations. Additionally, MFS has agreed to bear all expenses associated with office space, other administrative support, and supplies provided to the ICCO and Assistant ICCO.

The fund invests in the MFS Institutional Money Market Portfolio which is managed by MFS and seeks a high level of current income consistent with preservation of capital and liquidity. Income earned on this investment is included in “Dividends from underlying affiliated funds” on the Statement of Operations. This money market fund does not pay a management fee to MFS.

On May 31, 2012, MFS purchased 5,770 shares of Class R5 for an aggregate amount of $100,000. At October 31, 2012, MFS held 100%, 88%, 87%, and 100% of the outstanding shares of Class R1, Class R2, Class R3, and Class R5, respectively.

(4) Portfolio Securities

Purchases and sales of investments, other than U.S. Government securities and short-term obligations, aggregated $184,210,066 and $205,878,439, respectively.

(5) Shares of Beneficial Interest

The fund’s Declaration of Trust permits the Trustees to issue an unlimited number of full and fractional shares of beneficial interest. Transactions in fund shares were as follows:

	Year ended 10/31/12				Year ended 10/31/11 (i)
	Shares		Amount		Shares		Amount
Shares sold
Class A		852,116		$15,141,159		2,464,718		$41,847,783
Class B		37,749		650,828		110,139		1,847,652
Class C		111,348		1,912,365		439,963		7,362,604
Class I		701,692		12,843,723		481,667		8,015,820
Class R1		12		214		224		3,656
Class R2		194		3,351		583		9,655
Class R3		142		2,497		683		12,444
Class R4		54,995		1,004,511		91,957		1,574,093
Class R5 (formerly Class W)		18,578		323,165		1,096,469		19,455,681
		1,776,826		$31,881,813		4,686,403		$80,129,388

30

Notes to Financial Statements – continued

	Year ended 10/31/12						Year ended 10/31/11 (i)
	Shares			Amount			Shares			Amount
Shares issued to shareholders in reinvestment of distributions
Class A		64,688			$1,023,368			39,046			$657,545
Class B		2,496			38,490			781			12,799
Class C		6,809			105,065			1,339			21,968
Class I		317			5,027			—			—
Class R1		35			532			11			179
Class R2		69			1,072			34			561
Class R3		84			1,334			44			741
Class R4		4,834			76,563			3,552			59,880
Class R5 (formerly Class W)		4,005			63,519			3,058			51,525
		83,337			$1,314,970			47,865			$805,198
Shares reacquired
Class A		(1,835,646	)		$(32,762,705	)		(2,644,252	)		$(44,574,000	)
Class B		(139,586	)		(2,393,855	)		(227,468	)		(3,744,297	)
Class C		(416,153	)		(7,165,752	)		(662,405	)		(10,857,614	)
Class I		(363,605	)		(6,420,118	)		(36,712	)		(611,547	)
Class R1		(236	)		(4,110	)		(1	)		(22	)
Class R2		(18	)		(330	)		(5	)		(83	)
Class R4		(55,268	)		(1,000,788	)		(101,606	)		(1,700,936	)
Class R5 (formerly Class W)		(349,514	)		(6,249,480	)		(1,597,587	)		(26,412,005	)
		(3,160,026	)		$(55,997,138	)		(5,270,036	)		$(87,900,504	)
Net change
Class A		(918,842	)		$(16,598,178	)		(140,488	)		$(2,068,672	)
Class B		(99,341	)		(1,704,537	)		(116,548	)		(1,883,846	)
Class C		(297,996	)		(5,148,322	)		(221,103	)		(3,473,042	)
Class I		338,404			6,428,632			444,955			7,404,273
Class R1		(189	)		(3,364	)		234			3,813
Class R2		245			4,093			612			10,133
Class R3		226			3,831			727			13,185
Class R4		4,561			80,286			(6,097	)		(66,963	)
Class R5 (formerly Class W)		(326,931	)		(5,862,796	)		(498,060	)		(6,904,799	)
		(1,299,863	)		$(22,800,355	)		(535,768	)		$(6,965,918	)

(i) For Class I, the period is from inception, February 28, 2011, through the stated period end.

Redesignation of Class W to Class R5 – On May 10, 2012, sales of Class W shares (including exchanges) were suspended. On May 11, 2012, certain Class W shares were automatically converted to Class I shares. Shareholders of certain Class W shares became shareholders of Class I and received Class I shares with a total net asset value equal to their Class W shares at the time of the conversion. On May 30, 2012, remaining Class W shares, which represented MFS seed money, were redesignated Class R5. Class R5 shares are generally available only to certain eligible retirement plans

31

Notes to Financial Statements – continued

and to funds distributed by MFD. Class R5 shares do not pay a 12b-1 distribution fee or sub-accounting costs. On June 1, 2012, Class R5 shares were offered for sale to the public.

(6) Line of Credit

The fund and certain other funds managed by MFS participate in a $1.1 billion unsecured committed line of credit, subject to a $1 billion sublimit, provided by a syndication of banks under a credit agreement. Borrowings may be made for temporary financing needs. Interest is charged to each fund, based on its borrowings, generally at a rate equal to the higher of the Federal Reserve funds rate or one month LIBOR plus an agreed upon spread. A commitment fee, based on the average daily, unused portion of the committed line of credit, is allocated among the participating funds at the end of each calendar quarter. In addition, the fund and other funds managed by MFS have established unsecured uncommitted borrowing arrangements with certain banks for temporary financing needs. Interest is charged to each fund, based on its borrowings, at a rate equal to the Federal Reserve funds rate plus an agreed upon spread. For the year ended October 31, 2012, the fund’s commitment fee and interest expense were $1,008 and $0, respectively, and are included in “Miscellaneous” expense on the Statement of Operations.

(7) Transactions in Underlying Affiliated Funds-Affiliated Issuers

An affiliated issuer may be considered one in which the fund owns 5% or more of the outstanding voting securities, or a company which is under common control. For the purposes of this report, the fund assumes the following to be an affiliated issuer:

Underlying Affiliated Fund	Beginning Shares/Par Amount		Acquisitions Shares/Par Amount		Dispositions Shares/Par Amount			Ending Shares/Par Amount
MFS Institutional Money Market Portfolio		174,611		35,441,993		(34,808,662	)		807,942
Underlying Affiliated Fund	Realized Gain (Loss)		Capital Gain Distributions		Dividend Income			Ending Value
MFS Institutional Money Market Portfolio		$—		$—		$1,238			$807,942

32

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Board of Trustees of MFS Series Trust XII and Shareholders of MFS Equity Opportunities Fund:

We have audited the accompanying statement of assets and liabilities of MFS Equity Opportunities Fund (one of the portfolios comprising the MFS Series Trust XII), (the “Fund”), including the portfolio of investments, as of October 31, 2012, and the related statement of operations for the year then ended, the statements of changes in net assets for each of the two years in the period then ended, and the financial highlights for each of the periods indicated therein. These financial statements and financial highlights are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements and financial highlights based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements and financial highlights are free of material misstatement. We were not engaged to perform an audit of the Fund’s internal control over financial reporting. Our audits included consideration of internal control over financial reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the Fund’s internal control over financial reporting. Accordingly, we express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements and financial highlights, assessing the accounting principles used and significant estimates made by management, and evaluating the overall financial statement presentation. Our procedures included confirmation of securities owned as of October 31, 2012, by correspondence with the custodian and brokers. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements and financial highlights referred to above present fairly, in all material respects, the financial position of MFS Equity Opportunities Fund at October 31, 2012, the results of its operations for the year then ended, the changes in its net assets for each of the two years in the period then ended and the financial highlights for each of the periods indicated therein, in conformity with U.S. generally accepted accounting principles.

Boston, Massachusetts

December 14, 2012

33

TRUSTEES AND OFFICERS — IDENTIFICATION AND BACKGROUND

The Trustees and officers of the Trust, as of December 1, 2012, are listed below, together with their principal occupations during the past five years. (Their titles may have varied during that period.) The address of each Trustee and officer is 111 Huntington Avenue, Boston, Massachusetts 02199-7618.

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
INTERESTED TRUSTEES
Robert J. Manning (k) (age 49)	Trustee	February 2004	Massachusetts Financial Services Company, Chairman, Chief Executive Officer and Director; President (until December 2009); Chief Investment Officer (until July 2010)	N/A
INDEPENDENT TRUSTEES
David H. Gunning (age 70)	Trustee and Chair of Trustees	January 2004	Retired; Cleveland-Cliffs Inc. (mining products and service provider), Vice Chairman/Director (until 2007)	Lincoln Electric Holdings, Inc. (welding equipment manufacturer), Director; Development Alternatives, Inc. (consulting), Director/Non-Executive Chairman; Portman Limited (mining), Director (until 2008)
Robert E. Butler (age 71)	Trustee	January 2006	Consultant – investment company industry regulatory and compliance matters	N/A
Maureen R. Goldfarb (age 57)	Trustee	January 2009	Private investor	N/A
William R. Gutow (age 71)	Trustee	December 1993	Private investor and real estate consultant; Capitol Entertainment Management Company (video franchise), Vice Chairman	Atlantic Coast Tan (tanning salons), Vice Chairman (until 2007); Texas Donuts (donut franchise), Vice Chairman (until 2010)
Michael Hegarty (age 67)	Trustee	December 2004	Private investor; Rouse Properties Inc. (real estate), Director	N/A

34

Trustees and Officers – continued

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
John P. Kavanaugh (age 58)	Trustee	January 2009	Private investor	N/A
J. Dale Sherratt (age 74)	Trustee	June 1989	Insight Resources, Inc. (acquisition planning specialists), President; Wellfleet Investments (investor in health care companies), Managing General Partner	N/A
Laurie J. Thomsen (age 55)	Trustee	March 2005	Private investor; New Profit, Inc. (venture philanthropy), Executive Partner (until 2010)	The Travelers Companies (insurance), Director
Robert W. Uek (age 71)	Trustee	January 2006	Consultant to investment company industry	N/A
OFFICERS
John M. Corcoran (k) (age 47)	President	October 2008	Massachusetts Financial Services Company, Senior Vice President (since October 2008); State Street Bank and Trust (financial services provider), Senior Vice President, (until September 2008)	N/A
Christopher R. Bohane (k) (age 38)	Assistant Secretary and Assistant Clerk	July 2005	Massachusetts Financial Services Company, Vice President and Senior Counsel	N/A
Kino Clark (k) (age 44)	Assistant Treasurer	January 2012	Massachusetts Financial Services Company, Vice President	N/A
Thomas H. Connors (k) (age 53)	Assistant Secretary and Assistant Clerk	September 2012	Massachusetts Financial Services Company, Vice President and Senior Counsel; Deutsche Asset Management, Director and Senior Counsel (until 2012)	N/A

35

Trustees and Officers – continued

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
Ethan D. Corey (k) (age 49)	Assistant Secretary and Assistant Clerk	July 2005	Massachusetts Financial Services Company, Senior Vice President and Associate General Counsel	N/A
David L. DiLorenzo (k) (age 44)	Treasurer	July 2005	Massachusetts Financial Services Company, Senior Vice President	N/A
Robyn L. Griffin (age 37)	Assistant Independent Chief Compliance Officer	August 2008	Griffin Compliance LLC (provider of compliance services), Principal (since August 2008); State Street Corporation (financial services provider), Mutual Fund Administration Assistant Vice President (October 2006 – July 2008);	N/A
Brian E. Langenfeld (k) (age 39)	Assistant Secretary and Assistant Clerk	June 2006	Massachusetts Financial Services Company, Vice President and Senior Counsel	N/A
Susan S. Newton (k) (age 62)	Assistant Secretary and Assistant Clerk	May 2005	Massachusetts Financial Services Company, Senior Vice President and Associate General Counsel	N/A
Susan A. Pereira (k) (age 42)	Assistant Secretary and Assistant Clerk	July 2005	Massachusetts Financial Services Company, Vice President and Senior Counsel	N/A
Kasey L. Phillips (k) (age 41)	Assistant Treasurer	September 2012	Massachusetts Financial Services Company, Vice President; Wells Fargo Funds Management, LLC, Senior Vice President, Fund Treasurer (until 2012)	N/A

36

Trustees and Officers – continued

Name, Age	Position(s) Held with Fund	Trustee/Officer Since (h)	Principal Occupations During the Past Five Years	Other Directorships (j)
Mark N. Polebaum (k) (age 60)	Secretary and Clerk	January 2006	Massachusetts Financial Services Company, Executive Vice President, General Counsel and Secretary	N/A
Frank L. Tarantino (age 68)	Independent Chief Compliance Officer	June 2004	Tarantino LLC (provider of compliance services), Principal	N/A
Richard S. Weitzel (k) (age 42)	Assistant Secretary and Assistant Clerk	October 2007	Massachusetts Financial Services Company, Senior Vice President and Associate General Counsel	N/A
James O. Yost (k) (age 52)	Deputy Treasurer	September 1990	Massachusetts Financial Services Company, Senior Vice President	N/A

(h) Date first appointed to serve as Trustee/officer of an MFS fund. Each Trustee has served continuously since appointment unless indicated otherwise. For the period from December 15, 2004 until February 22, 2005, Mr. Manning served as Advisory Trustee. For the period October 2008, until January 2012, Mr. Corcoran served as Treasurer of the Funds. Prior to January 2012, Messrs. DiLorenzo and Yost served as Assistant Treasurers of the Funds.

(j) Directorships or trusteeships of companies required to report to the Securities and Exchange Commission (i.e., “public companies”).

(k) “Interested person” of the Trust within the meaning of the Investment Company Act of 1940 (referred to as the 1940 Act), which is the principal federal law governing investment companies like the fund, as a result of position with MFS. The address of MFS is 111 Huntington Avenue, Boston, Massachusetts 02199-7618.

Each Trustee has been elected by shareholders and each Trustee and officer holds office until his or her successor is chosen and qualified or until his or her earlier death, resignation, retirement or removal. The Trust does not hold annual meetings for the purpose of electing Trustees, and Trustees are not elected for fixed terms. Messrs. Butler, Kavanaugh, Uek and Ms. Thomsen are members of the Trust’s Audit Committee.

Each of the Fund’s Trustees and officers holds comparable positions with certain other funds of which MFS or a subsidiary is the investment adviser or distributor, and, in the case of the officers, with certain affiliates of MFS. As of January 1, 2012, the Trustees served as board members of 131 funds within the MFS Family of Funds.

37

Trustees and Officers – continued

The Statement of Additional Information for the Fund includes further information about the Trustees and is available without charge upon request by calling 1-800-225-2606.

Investment Adviser	Custodian
Massachusetts Financial Services Company 111 Huntington Avenue Boston, MA 02199-7618	State Street Bank and Trust 1 Lincoln Street Boston, MA 02111-2900
Distributor	Independent Registered Public Accounting Firm
MFS Fund Distributors, Inc. 111 Huntington Avenue Boston, MA 02199-7618	Ernst & Young LLP 200 Clarendon Street Boston, MA 02116
Portfolio Manager
Matthew Krummel

38

BOARD REVIEW OF INVESTMENT ADVISORY AGREEMENT

The Investment Company Act of 1940 requires that both the full Board of Trustees and a majority of the non-interested (“independent”) Trustees, voting separately, annually approve the continuation of the Fund’s investment advisory agreement with MFS. The Trustees consider matters bearing on the Fund and its advisory arrangements at their meetings throughout the year, including a review of performance data at each regular meeting. In addition, the independent Trustees met several times over the course of three months beginning in May and ending in July, 2012 (“contract review meetings”) for the specific purpose of considering whether to approve the continuation of the investment advisory agreement for the Fund and the other investment companies that the Board oversees (the “MFS Funds”). The independent Trustees were assisted in their evaluation of the Fund’s investment advisory agreement by independent legal counsel, from whom they received separate legal advice and with whom they met separately from MFS during various contract review meetings. The independent Trustees were also assisted in this process by the MFS Funds’ Independent Chief Compliance Officer, a full-time senior officer appointed by and reporting to the independent Trustees.

In connection with their deliberations regarding the continuation of the investment advisory agreement, the Trustees, including the independent Trustees, considered such information and factors as they believed, in light of the legal advice furnished to them and their own business judgment, to be relevant. The investment advisory agreement for the Fund was considered separately, although the Trustees also took into account the common interests of all MFS Funds in their review. As described below, the Trustees considered the nature, quality, and extent of the various investment advisory, administrative, and shareholder services performed by MFS under the existing investment advisory agreement and other arrangements with the Fund.

In connection with their contract review meetings, the Trustees received and relied upon materials that included, among other items: (i) information provided by Lipper Inc., an independent third party, on the investment performance of the Fund for various time periods ended December 31, 2011 and the investment performance of a group of funds with substantially similar investment classifications/objectives (the “Lipper performance universe”), (ii) information provided by Lipper Inc. on the Fund’s advisory fees and other expenses and the advisory fees and other expenses of comparable funds identified by Lipper Inc. (the “Lipper expense group”), (iii) information provided by MFS on the advisory fees of comparable portfolios of other clients of MFS, including institutional separate accounts and other clients, (iv) information as to whether and to what extent applicable expense waivers, reimbursements or fee “breakpoints” are observed for the Fund, (v) information regarding MFS’ financial results and financial condition, including MFS’ and certain of its affiliates’ estimated profitability from services performed for the Fund and the MFS Funds as a whole, and compared to MFS’ institutional business, (vi) MFS’ views regarding the outlook for the mutual fund industry and the strategic business plans of MFS, (vii) descriptions of various functions performed by MFS for the Funds, such as compliance monitoring and portfolio trading practices, and (viii) information regarding the overall organization of MFS, including information about MFS’ senior management and other personnel providing investment advisory, administrative and other services to

39

Board Review of Investment Advisory Agreement – continued

the Fund and the other MFS Funds. The comparative performance, fee and expense information prepared and provided by Lipper Inc. was not independently verified and the independent Trustees did not independently verify any information provided to them by MFS.

The Trustees’ conclusion as to the continuation of the investment advisory agreement was based on a comprehensive consideration of all information provided to the Trustees and not the result of any single factor. Some of the factors that figured particularly in the Trustees’ deliberations are described below, although individual Trustees may have evaluated the information presented differently from one another, giving different weights to various factors. It is also important to recognize that the fee arrangements for the Fund and other MFS Funds are the result of years of review and discussion between the independent Trustees and MFS, that certain aspects of such arrangements may receive greater scrutiny in some years than in others, and that the Trustees’ conclusions may be based, in part, on their consideration of these same arrangements during the course of the year and in prior years.

In January 2007, the Fund acquired all of the assets and identified liabilities of the Penn Street Advisors Sector Rotational Portfolio, the fund’s predecessor (the “Predecessor Fund”), and assumed the performance record of the Predecessor Fund. As a result, performance information for the Fund includes the performance of the Predecessor Fund adjusted to reflect the Fund’s applicable sales charges.

Based on information provided by Lipper Inc. and MFS, the Trustees reviewed the Fund’s total return investment performance as well as the performance of peer groups of funds over various time periods. The Trustees placed particular emphasis on the total return performance of the Fund’s Class A shares in comparison to the performance of funds in its Lipper performance universe over the three-year period ended December 31, 2011, which the Trustees believed was a long enough period to reflect differing market conditions. The total return performance of the Fund’s Class A shares was in the 4th quintile relative to the other funds in the universe for this three-year period (the 1st quintile being the best performers and the 5th quintile being the worst performers). The total return performance of the Fund’s Class A shares was in the 3rd quintile for each of the one- and five-year periods ended December 31, 2011 relative to the Lipper performance universe. Because of the passage of time, these performance results may differ from the performance results for more recent periods, including those shown elsewhere in this report.

The Trustees expressed continued concern to MFS about the substandard investment performance of the Fund. In the course of their deliberations, the Trustees took into account information provided by MFS in connection with the contract review meetings, as well as during investment review meetings conducted with portfolio management personnel during the course of the year, as to MFS’ efforts to improve the Fund’s performance, including the termination of the sub-advisory relationship with Valley Forge Capital Advisors, Inc. and the assignment of an MFS portfolio manager for the Fund in 2010. In addition, the Trustees requested that they receive a separate update on the Fund’s performance at each of their regular meetings. After reviewing these and related factors, the Trustees concluded, within the context of their overall conclusions regarding the investment advisory agreement, that MFS’ responses and efforts and plans to improve investment performance were sufficient to support approval of the

40

Board Review of Investment Advisory Agreement – continued

continuance of the investment advisory agreement for an additional one-year period, but that they would continue to closely monitor the performance of the Fund.

In assessing the reasonableness of the Fund’s advisory fee, the Trustees considered, among other information, the Fund’s advisory fee and the total expense ratio of the Fund’s Class A shares as a percentage of average daily net assets and the advisory fee and total expense ratios of peer groups of funds based on information provided by Lipper Inc. The Trustees considered that MFS currently observes an expense limitation for the Fund, which may not be changed without the Trustees’ approval. The Trustees also considered that, according to the Lipper data (which takes into account any fee reductions or expense limitations that were in effect during the Fund’s last fiscal year), the Fund’s effective advisory fee rate and total expense ratio were each approximately at the Lipper expense group median.

The Trustees also considered the advisory fees charged by MFS to institutional accounts, if any. In comparing these fees, the Trustees considered information provided by MFS as to the generally broader scope of services provided by MFS to the Fund in comparison to institutional accounts, the higher demands placed on MFS’ investment personnel and trading infrastructure as a result of the daily cash in-flows and out-flows of the Fund, and the impact on MFS and expenses associated with the more extensive regulatory regime to which the Fund is subject in comparison to institutional accounts.

The Trustees also considered whether the Fund is likely to benefit from any economies of scale in the management of the Fund in the event of growth in assets of the Fund. They noted that the Fund’s advisory fee rate schedule is subject to contractual breakpoints that reduce the Fund’s advisory fee rate on average daily net assets over $1 billion, $2.5 billion and $5 billion. The Trustees concluded that the existing breakpoints were sufficient to allow the Fund to benefit from economies of scale as its assets grow.

The Trustees also considered information prepared by MFS relating to MFS’ costs and profits with respect to the Fund, the MFS Funds considered as a group, and other investment companies and accounts advised by MFS, as well as MFS’ methodologies used to determine and allocate its costs to the MFS Funds, the Fund and other accounts and products for purposes of estimating profitability.

After reviewing these and other factors described herein, the Trustees concluded, within the context of their overall conclusions regarding the investment advisory agreement, that the advisory fees charged to the Fund represent reasonable compensation in light of the services being provided by MFS to the Fund.

In addition, the Trustees considered MFS’ resources and related efforts to continue to retain, attract and motivate capable personnel to serve the Fund. The Trustees also considered current and developing conditions in the financial services industry, including the presence of large and well-capitalized companies which are spending, and appear to be prepared to continue to spend, substantial sums to engage personnel and to provide services to competing investment companies. In this regard, the Trustees also considered the financial resources of MFS and its ultimate parent, Sun Life Financial Inc. The Trustees also considered the advantages and possible disadvantages to the Fund of having an adviser that also serves other investment companies as well as other accounts.

41

Board Review of Investment Advisory Agreement – continued

The Trustees also considered the nature, quality, cost, and extent of administrative, transfer agency, and distribution services provided to the Fund by MFS and its affiliates under agreements and plans other than the investment advisory agreement, including any 12b-1 fees the Fund pays to MFS Fund Distributors, Inc., an affiliate of MFS. The Trustees also considered the nature, extent and quality of certain other services MFS performs or arranges for on the Fund’s behalf, which may include securities lending programs, directed expense payment programs, class action recovery programs, and MFS’ interaction with third-party service providers, principally custodians and sub-custodians. The Trustees concluded that the various non-advisory services provided by MFS and its affiliates on behalf of the Fund were satisfactory.

The Trustees also considered benefits to MFS from the use of the Fund’s portfolio brokerage commissions, if applicable, to pay for investment research and various other factors. Additionally, the Trustees considered so-called “fall-out benefits” to MFS such as reputational value derived from serving as investment manager to the Fund.

Based on their evaluation of factors that they deemed to be material, including those factors described above, the Board of Trustees, including the independent Trustees, concluded that the Fund’s investment advisory agreement with MFS should be continued for an additional one-year period, commencing August 1, 2012.

A discussion regarding the Board’s most recent review and renewal of the fund’s Investment Advisory Agreement with MFS is available by clicking on the fund’s name under “Mutual Funds” in the “Products and Performance” section of the MFS Web site (mfs.com).

42

PROXY VOTING POLICIES AND INFORMATION

A general description of the MFS funds’ proxy voting policies and procedures is available without charge, upon request, by calling 1-800-225-2606, by visiting the Proxy Voting section of mfs.com or by visiting the SEC’s Web site at http://www.sec.gov.

Information regarding how the fund voted proxies relating to portfolio securities during the most recent twelve-month period ended June 30 is available without charge by visiting the Proxy Voting section of mfs.com or by visiting the SEC’s Web site at http://www.sec.gov.

QUARTERLY PORTFOLIO DISCLOSURE

The fund will file a complete schedule of portfolio holdings with the Securities and Exchange Commission (the Commission) for the first and third quarters of each fiscal year on Form N-Q. A shareholder can obtain the quarterly portfolio holdings report at mfs.com. The fund’s Form N-Q is also available on the EDGAR database on the Commission’s Internet Web site at http://www.sec.gov, and may be reviewed and copied at the:

Public Reference Room

Securities and Exchange Commission

100 F Street, NE, Room 1580

Washington, D.C. 20549

Information on the operation of the Public Reference Room may be obtained by calling the Commission at 1-800-SEC-0330. Copies of the fund’s Form N-Q also may be obtained, upon payment of a duplicating fee, by electronic request at the following e-mail address: publicinfo@sec.gov or by writing the Public Reference Section at the above address.

FURTHER INFORMATION

From time to time, MFS may post important information about the fund or the MFS funds on the MFS web site (mfs.com). This information is available by visiting the “News & Commentary” section of mfs.com or by clicking on the fund’s name under “Mutual Funds” in the “Products and Performance” section of mfs.com.

FEDERAL TAX INFORMATION (unaudited)

The fund will notify shareholders of amounts for use in preparing 2012 income tax forms in January 2013. The following information is provided pursuant to provisions of the Internal Revenue Code.

The fund designates the maximum amount allowable as qualified dividend income eligible for the 15% tax rate.

For corporate shareholders, 100% of the ordinary income dividends paid during the fiscal year qualify for the corporate dividends received deduction.

43

rev. 3/11

FACTS WHAT DOES MFS DO WITH YOUR PERSONAL INFORMATION?

Why? Financial companies choose how they share your personal information. Federal law gives consumers the right to limit some but not all sharing. Federal law also requires us to tell you how we collect, share, and protect your personal information. Please read this notice carefully to understand what we do.

What? The types of personal information we collect and share depend on the product or service you have with us. This information can include:   • Social Security number and account balances • Account transactions and transaction history • Checking account information and wire transfer instructions   When you are no longer our customer, we continue to share your information as described in this notice.

How? All financial companies need to share customers’ personal information to run their everyday business. In the section below, we list the reasons financial companies can share their customers’ personal information; the reasons MFS chooses to share; and whether you can limit this sharing.

Reasons we can share your personal information	Does MFS share?	Can you limit this sharing?
For our everyday business purposes – such as to process your transactions, maintain your account(s), respond to court orders and legal investigations, or report to credit bureaus	Yes	No
For our marketing purposes – to offer our products and services to you	No	We don’t share
For joint marketing with other financial companies	No	We don’t share
For our affiliates’ everyday business purposes – information about your transactions and experiences	No	We don’t share
For our affiliates’ everyday business purposes – information about your creditworthiness	No	We don’t share
For nonaffiliates to market to you	No	We don’t share

Questions? Call 800-225-2606 or go to mfs.com.

44

Page 2

Who we are
Who is providing this notice?	MFS Funds, MFS Investment Management, MFS Institutional Advisors, Inc., MFS Fund Distributors, Inc., MFS Heritage Trust Company, and MFS Service Center, Inc.

What we do
How does MFS protect my personal information?	To protect your personal information from unauthorized access and use, we use security measures that comply with federal law. These measures include procedural, electronic, and physical safeguards for the protection of the personal information we collect about you.
How does MFS collect my personal information?	We collect your personal information, for example, when you • open an account or provide account information • direct us to buy securities or direct us to sell your securities • make a wire transfer We also collect your personal information from others, such as credit bureaus, affiliates and other companies.
Why can’t I limit all sharing?	Federal law gives you the right to limit only • sharing for affiliates’ everyday business purposes – information about your creditworthiness • affiliates from using your information to market to you • sharing for nonaffiliates to market to you State laws and individual companies may give you additional rights to limit sharing.

Definitions
Affiliates	Companies related by common ownership or control. They can be financial and nonfinancial companies. • MFS does not share personal information with affiliates, except for everyday business purposes as described on page one of this notice.
Nonaffiliates	Companies not related by common ownership or control. They can be financial and nonfinancial companies. • MFS does not share with nonaffiliates so they can market to you.
Joint Marketing	A formal agreement between nonaffiliated financial companies that together market financial products or services to you. • MFS doesn’t jointly market.

Other important information

If you own an MFS product or receive an MFS service in the name of a third party such as a bank or broker-dealer, their privacy policy may apply to you instead of ours.

45

Save paper with eDelivery.

MFS® will send you prospectuses,

reports, and proxies directly via e-mail so you will get information faster with less mailbox clutter.

To sign up:

1. Go to mfs.com.

2. Log in via MFS® Access.

3. Select eDelivery.

If you own your MFS fund shares through a financial institution or a retirement plan, MFS® TALK, MFS® Access, or eDelivery may not be available to you.

CONTACT

WEB SITE

mfs.com

MFS TALK

1-800-637-8255

24 hours a day

ACCOUNT SERVICE AND LITERATURE

Shareholders

1-800-225-2606

Financial advisors

1-800-343-2829

Retirement plan services

1-800-637-1255

MAILING ADDRESS

MFS Service Center, Inc.

P.O. Box 55824

Boston, MA 02205-5824

OVERNIGHT MAIL

MFS Service Center, Inc.

c/o Boston Financial Data Services

30 Dan Road

Canton, MA 02021-2809

ITEM 2. CODE OF ETHICS.

The Registrant has adopted a Code of Ethics pursuant to Section 406 of the Sarbanes-Oxley Act and as defined in Form N-CSR that applies to the Registrant’s principal executive officer and principal financial and accounting officer. During the period covered by this report, the Registrant has not amended any provision in its Code of Ethics (the “Code”) that relates to an element of the Code’s definitions enumerated in paragraph (b) of Item 2 of this Form N-CSR. During the period covered by this report, the Registrant did not grant a waiver, including an implicit waiver, from any provision of the Code.

A copy of the Code of Ethics is filed as an exhibit to this Form N-CSR.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Messrs. Robert E. Butler, John P. Kavanaugh and Robert W. Uek and Ms. Laurie J. Thomsen, members of the Audit Committee, have been determined by the Board of Trustees in their reasonable business judgment to meet the definition of “audit committee financial expert” as such term is defined in Form N-CSR. In addition, Messrs. Butler, Kavanaugh and Uek and Ms. Thomsen are “independent” members of the Audit Committee (as such term has been defined by the Securities and Exchange Commission in regulations implementing Section 407 of the Sarbanes-Oxley Act of 2002). The Securities and Exchange Commission has stated that the designation of a person as an audit committee financial expert pursuant to this Item 3 on the Form N-CSR does not impose on such a person any duties, obligations or liability that are greater than the duties, obligations or liability imposed on such person as a member of the Audit Committee and the Board of Trustees in the absence of such designation or identification.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Items 4(a) through 4(d) and 4(g):

The Board of Trustees has appointed Ernst & Young LLP (“E&Y”) to serve as independent accountants to the series of the Registrant (the series referred to as the “Fund”). The tables below set forth the audit fees billed to the Fund as well as fees for non-audit services provided to the Fund and/or to the Fund’s investment adviser, Massachusetts Financial Services Company (“MFS”) and to various entities either controlling, controlled by, or under common control with MFS that provide ongoing services to the Fund (“MFS Related Entities”).

For the fiscal years ended October 31, 2012 and 2011, audit fees billed to the Fund by E&Y were as follows:

	Audit Fees
Fees billed by E&Y:	2012		2011
MFS Equity Opportunities Fund		34,954		33,672

For the fiscal years ended October 31, 2012 and 2011, fees billed by E&Y for audit-related, tax and other services provided to the Fund and for audit-related, tax and other services provided to MFS and MFS Related Entities were as follows:

	Audit-Related Fees1				Tax Fees2				All Other  Fees3
Fees billed by E&Y:	2012		2011		2012		2011		2012		2011
To MFS Equity Opportunities Fund		0		0		7,790		7,377		0		0
	Audit-Related Fees1				Tax Fees2				All Other  Fees3
Fees billed by E&Y:	2012		2011		2012		2011		2012		2011
To MFS and MFS Related Entities of MFS Equity Opportunities Fund*		0		0		0		0		0		0
Aggregate fees for non-audit services:

	2012		20114
To MFS Equity Opportunities Fund, MFS and MFS Related Entities#		47,790		117,377

^*  This amount reflects the fees billed to MFS and MFS Related Entities for non-audit services relating directly to the operations and financial reporting of the Fund (portions of which services also related to the operations and financial reporting of other funds within the MFS Funds complex).

# This amount reflects the aggregate fees billed by E&Y for non-audit services rendered to the Fund and for non-audit services rendered to MFS and the MFS Related Entities.

¹  The fees included under “Audit-Related Fees” are fees related to assurance and related services that are reasonably related to the performance of the audit or review of financial statements, but not reported under “Audit Fees,” including accounting consultations, agreed-upon procedure reports, attestation reports, comfort letters and internal control reviews.

²  The fees included under “Tax Fees” are fees associated with tax compliance, tax advice and tax planning, including services relating to the filing or amendment of federal, state or local income tax returns, regulated investment company qualification reviews and tax distribution and analysis.

³  The fees under “All Other Fees” are fees for products and services provided by E&Y other than those reported under “Audit Fees,” “Audit-Related Fees” and “Tax Fees”.

⁴  E&Y fees reported in 2011 have been restated in this filing from those reported in the Registrant’s filing for the reporting period ended October 31, 2011.

Item 4(e)(1):

Set forth below are the policies and procedures established by the Audit Committee of the Board of Trustees relating to the pre-approval of audit and non-audit related services:

To the extent required by applicable law, pre-approval by the Audit Committee of the Board is needed for all audit and permissible non-audit services rendered to the Funds and all permissible non-audit services rendered to MFS or MFS Related Entities if the services relate directly to the operations and financial reporting of the Registrant. Pre-approval is currently on an engagement-by-engagement basis. In the event pre-approval of such services is necessary between regular meetings of the Audit Committee and it is not practical to wait to seek pre-approval at the next regular meeting of the Audit Committee, pre-approval of such services may be referred to the Chair of the Audit Committee for approval; provided that the Chair may not pre-approve any individual engagement for such services exceeding $50,000 or multiple engagements for such services in the aggregate exceeding $100,000 in each period between regular meetings of the Audit Committee. Any engagement pre-approved by the Chair between regular meetings of the Audit Committee shall be presented for ratification by the entire Audit Committee at its next regularly scheduled meeting.

Item 4(e)(2):

None, or 0%, of the services relating to the Audit-Related Fees, Tax Fees and All Other Fees paid by the Fund and MFS and MFS Related Entities relating directly to the operations and financial reporting of the Registrant disclosed above were approved by the audit committee pursuant to paragraphs (c)(7)(i)(C) of Rule 2-01 of Regulation S-X (which permits audit committee approval after the start of the engagement with respect to services other than audit, review or attest services, if certain conditions are satisfied).

Item 4(f): Not applicable.

Item 4(h): The Registrant’s Audit Committee has considered whether the provision by a Registrant’s independent registered public accounting firm of non-audit services to MFS and MFS Related Entities that were not pre-approved by the Committee (because such services did not relate directly to the operations and financial reporting of the Registrant) was compatible with maintaining the independence of the independent registered public accounting firm as the Registrant’s principal auditors.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable to the Registrant.

ITEM 6. INVESTMENTS

A schedule of investments of the Registrant is included as part of the report to shareholders of such series under Item 1 of this Form N-CSR.

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to the Registrant.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT COMPANY AND AFFILIATED PURCHASERS.

Not applicable to the Registrant.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

There were no material changes to the procedures by which shareholders may send recommendations to the Board for nominees to the Registrant’s Board since the Registrant last provided disclosure as to such procedures in response to the requirements of Item 407 (c)(2)(iv) of Regulation S-K or this Item.

ITEM 11. CONTROLS AND PROCEDURES.

(a) Based upon their evaluation of the effectiveness of the registrant’s disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940 (the “Act”)) as conducted within 90 days of the filing date of this report on Form N-CSR, the registrant’s principal financial officer and principal executive officer have concluded that those disclosure controls and procedures provide reasonable assurance that the material information required to be disclosed by the registrant on this report is recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission’s rules and forms.

(b) There were no changes in the registrant’s internal controls over financial reporting (as defined in Rule 30a-3(d) under the Act) that occurred during the second fiscal quarter of the period covered by the report that have materially affected, or are reasonably likely to materially affect, the registrant’s internal control over financial reporting.

ITEM 12. EXHIBITS.

(a) File the exhibits listed below as part of this form. Letter or number the exhibits in the sequence indicated.

(1) Any code of ethics, or amendment thereto, that is the subject of the disclosure required by Item 2, to the extent that the registrant intends to satisfy the Item 2 requirements through filing of an exhibit: Code of Ethics attached hereto.

(2) A separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the Act (17 CFR 270.30a-2): Attached hereto.

(b) If the report is filed under Section 13(a) or 15(d) of the Exchange Act, provide the certifications required by Rule 30a-2(b) under the Act (17 CFR 270.30a-2(b)), Rule 13a-14(b) or Rule 15d-14(b) under the Exchange Act (17 CFR 240.13a-14(b) or 240.15d-14(b)) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. 1350) as an exhibit. A certification furnished pursuant to this paragraph will not be deemed “filed” for the purposes of Section 18 of the Exchange Act (15 U.S.C. 78r), or otherwise subject to the liability of that section. Such certification will not be deemed to be incorporated by reference into any filing under the Securities Act of 1933 or the Exchange Act, except to the extent that the registrant specifically incorporates it by reference: Attached hereto.

Notice

A copy of the Declaration of Trust, as amended, of the Registrant is on file with the Secretary of State of The Commonwealth of Massachusetts and notice is hereby given that this instrument is executed on behalf of the Registrant by an officer of the Registrant as an officer and not individually and the obligations of or arising out of this instrument are not binding upon any of the Trustees or shareholders individually, but are binding only upon the assets and property of the respective constituent series of the Registrant.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant) MFS SERIES TRUST XII

By (Signature and Title)*	JOHN M. CORCORAN
	John M. Corcoran, President

Date: December 14, 2012

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)*	JOHN M. CORCORAN
	John M. Corcoran, President (Principal Executive Officer)

Date: December 14, 2012

By (Signature and Title)*	DAVID L. DILORENZO
	David L. DiLorenzo, Treasurer (Principal Financial Officer and Accounting Officer)

Date: December 14, 2012

* Print name and title of each signing officer under his or her signature.

EX-99.(12)(A)(1)

Code of Ethics for Principal Executive and Principal Financial Officers

Owner:	Effective Date: February 22, 2010
General Counsel/Chief Legal Officer	Replaces Policy Version Dated: September 2003, last revised January 1, 2012
Contact Person: Mark Polebaum Susan Newton Applicability: MFS Funds	Policy Committee Approval: January 12, 2012

I. Policy Purpose and Summary

Section 406 of the Sarbanes-Oxley Act requires that the each MFS Fund registered under the Investment Company Act of 1940 adopt a code of ethics for senior financial officers, applicable to its principal financial officer and principal accounting officer.

II. Overview

A. Covered Officers/Purpose of the Code

This code of ethics (this “Code”) has been adopted by the funds (collectively, “Funds” and each, “Fund”) under supervision of the MFS Funds Board (the “Board”) and applies to the Funds’ Principal Executive Officer and Principal Financial Officer (the “Covered Officers” each of whom is set forth in Exhibit A) for the purpose of promoting:

• honest and ethical conduct, including the ethical handling of actual or apparent conflicts of interest between personal and professional relationships;

• full, fair, accurate, timely and understandable disclosure in reports and documents that the Funds file with, or submit to, the Securities and Exchange Commission (“SEC”) and in other public communications made by the Funds;

• compliance by the Funds with applicable laws and governmental rules and regulations;

• the prompt internal reporting of violations of the Code to an appropriate person or persons identified in the Code; and

• accountability for adherence to the Code.

B. Conduct Guidelines

Each Covered Officer should adhere to a high standard of business ethics and should be sensitive to situations that may give rise to actual as well as apparent conflicts of interest. In addition, each Covered Officer should not place his or her personal interests ahead of the Funds’ interests and should endeavor to act honestly and ethically. In furtherance of the foregoing, each Covered Officer must:

• not use his or her personal influence or personal relationships improperly to influence investment decisions or financial reporting for any Fund whereby the Covered Officer would benefit personally to the detriment of the Fund; and

• not cause a Fund to take action, or fail to take action, for the individual personal benefit of the Covered Officer rather than the benefit the Fund.

The following activities, which could create the appearance of a conflict of interest, are permitted only with the approval of the Funds’ Chief Legal Officer (“CLO”):

• service as a director on the board of any “for profit” company;

• running for political office;

• the receipt of any Fund business-related gift in excess of $300;

• the receipt of any entertainment from any company with which a Fund has current or prospective business dealings unless such entertainment is business-related, reasonable in cost, appropriate as to time and place, and not so frequent as to raise any question of impropriety;

• any material ownership interest in, or any consulting or employment relationship with, any Fund service providers (e.g., custodian banks, audit firms), other than the Funds’ investment adviser, principal underwriter, administrator or any affiliated person thereof;

• a direct or indirect financial interest in commissions, transaction charges or spreads paid by a Fund for effecting portfolio transactions or for selling or redeeming shares, other than an interest arising from the Covered Officer’s employment or securities ownership.

C. Disclosure and Compliance

• Each Covered Officer should familiarize himself or herself with the disclosure requirements generally applicable to the Funds;

• each Covered Officer should not knowingly misrepresent, or cause others to misrepresent, facts about a Fund to others, whether within or outside the Fund, including to the Fund’s trustees and auditors, and to governmental regulators and self-regulatory organizations;

• each Covered Officer should, to the extent appropriate within his or her area of Fund responsibility, consult with other officers and employees of the Funds and the adviser with the goal of promoting full, fair, accurate, timely and understandable disclosure in the reports and documents the Funds file with, or submit to, the SEC and in other public communications made by the Funds; and

• it is the responsibility of each Covered Officer to promote compliance within his or her area of Fund responsibility with the standards and restrictions imposed by applicable laws, rules and regulations.

D. Reporting and Accountability

Each Covered Officer must:

• upon adoption of the Code (or thereafter as applicable, upon becoming a Covered Officer), affirm in writing to the Boards that he or she has received, read, and understands the Code;

• annually thereafter affirm to the Boards that he or she has complied with the requirements of the Code;

• annually report to the CLO affiliations and relationships which are or may raise the appearance of a conflict of interest with the Covered Officer’s duties to the Funds, as identified in the annual Trustee and Officer Questionnaire;

• not retaliate against any other Covered Officer or any officer or employee of the Funds or their affiliated persons for reports of potential violations that are made in good faith; and

• notify the CLO promptly if he or she knows of any violation of this Code. Failure to do so is itself a violation of this Code.

The CLO is responsible for applying this Code to specific situations in which questions are presented under it, granting waivers upon consultation with the appropriate Board or its designee, investigating violations, and has the authority to interpret this Code in any particular situation. The CLO will report requests for waivers to the appropriate Board (or a designee thereof) promptly upon receipt of a waiver request and will periodically report to the appropriate Board any approvals granted since the last report.

The CLO will take all appropriate action to investigate any potential violations reported to him or her and to report any violations to the appropriate Board. If the Board concurs that a violation has occurred, it will consider appropriate action, which may include review of, and appropriate modifications to, applicable policies and procedures; notification to appropriate personnel of the investment adviser or its board; or a recommendation to dismiss the Covered Officer.

Any changes to or waivers of this Code will, to the extent required, be disclosed as provided by SEC rules.

E. Confidentiality

All reports and records prepared or maintained pursuant to this Code and under the direction of the CLO will be considered confidential and shall be maintained and protected accordingly. Except as otherwise required by law or this Code, such matters shall not be disclosed to anyone other than the appropriate Funds’ Board, its counsel, counsel to the Board’s independent trustees and senior management and the board of directors of the Fund’s investment adviser and its counsel.

F. Internal Use

The Code is intended solely for the internal use by the Funds and does not constitute an admission, by or on behalf of any Fund, as to any fact, circumstance, or legal conclusion.

III. Supervision

The Board of Trustees of the Fund, including a majority of the Trustees who are not “interested persons” (as defined in the 1940 Act) of the Fund, shall review no less frequently than annually, a report from the CLO regarding the affirmations of the principal executive officer and the principal financial officer as to compliance with this Code.

IV. Interpretation and Escalation

Breaches of the Code are reviewed by the CLO and communicated to the Board of Trustees of the affected Fund(s). Interpretations of this Policy shall be made from time to time by the CLO, as needed, and questions regarding the application of this Policy to a specific set of facts are escalated to the CLO.

V. Authority

Section 406 of the Sarbanes-Oxley Act.

VI. Monitoring

Adherence to this policy is monitored by the CLO.

VII. Related Policies

This Code shall be the sole code of ethics adopted by the Funds for purposes of Section 406 of the Sarbanes-Oxley Act and the rules and forms applicable to registered investment companies thereunder. Insofar as other policies or procedures of the Funds, the Funds’ adviser, principal underwriter, or other service providers govern or purport to govern the behavior or activities of the Covered Officers who are subject to this Code, they are superseded by this Code to the extent that they overlap or conflict with the provisions of this Code. The Funds’ and their investment adviser’s codes of ethics under Rule 17j-1 under the Investment Company Act and any other codes or policies or procedures adopted by the Funds or their investment adviser or other service providers are separate requirements and are not part of this Code.

VIII.  Amendment

Any amendments to this Code, other than amendments to Exhibit A, must be approved or ratified by a majority vote of each Board, including a majority of independent trustees.

IX. Recordkeeping

All required books, records and other documentation shall be retained in accordance with MFS’ related record retention policy.

Additional procedures may need to be implemented by departments to properly comply with this policy.

Exhibit A

As of January 1, 2012

Persons Covered by this Code of Ethics

Funds’ Principal Executive Officer: John M. Corcoran

Funds’ Principal Financial Officer: David L. DiLorenzo

EX-99.CERT

EX-99.CERT

MFS SERIES TRUST XII

CERTIFICATION PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT

I, David L. DiLorenzo, certify that:

1. I have reviewed this report on Form N-CSR of MFS Series Trust XII;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

a. Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b. Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c. Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures as of a date within 90 days prior to the filing date of this report based on such evaluation; and

d. Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the second fiscal quarter of the period covered by the report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: December 14, 2012	DAVID L. DILORENZO
	David L. DiLorenzo
	Treasurer (Principal Financial Officer and Accounting Officer)

EX-99.CERT

MFS SERIES TRUST XII

CERTIFICATION PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT

I, John M. Corcoran, certify that:

1. I have reviewed this report on Form N-CSR of MFS Series Trust XII;

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3. Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations, changes in net assets, and cash flows (if the financial statements are required to include a statement of cash flows) of the registrant as of, and for, the periods presented in this report;

4. The registrant’s other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) and internal control over financial reporting (as defined in Rule 30a-3(d) under the Investment Company Act of 1940) for the registrant and have:

a. Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b. Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c. Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures as of a date within 90 days prior to the filing date of this report based on such evaluation; and

d. Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the second fiscal quarter of the period covered by the report that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5. The registrant’s other certifying officer and I have disclosed to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a. All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize, and report financial information; and

b. Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: December 14, 2012	JOHN M. CORCORAN
	John M. Corcoran
	President (Principal Executive Officer)

EX-99.906CERT

EX-99.906CERT

MFS SERIES TRUST XII

CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT

I, David L. DiLorenzo, certify that, to my knowledge:

1. The Form N-CSR (the “Report”) of MFS Series Trust XII (the “Registrant”) fully complies for the period covered by the Report with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date: December 14, 2012	DAVID L. DILORENZO
	David L. DiLorenzo
	Treasurer (Principal Financial Officer and Accounting Officer)

A signed original of this written statement required by Section 906 has been provided to the Registrant and will be retained by the Registrant and furnished to the Securities and Exchange Commission or its staff upon request.

EX-99.906CERT

MFS SERIES TRUST XII

CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT

I, John M. Corcoran, certify that, to my knowledge:

1. The Form N-CSR (the “Report”) of MFS Series Trust XII (the “Registrant”) fully complies for the period covered by the Report with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

2. The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Registrant.

Date: December 14, 2012	JOHN M. CORCORAN
	John M. Corcoran
	President (Principal Executive Officer)

A signed original of this written statement required by Section 906 has been provided to the Registrant and will be retained by the Registrant and furnished to the Securities and Exchange Commission or its staff upon request.