Exhibit 99.1

NEWS RELEASE

For Immediate Release

For more information, contact:

Liz Bauer, Senior Vice President

(303) 804-4065

E-mail: liz_bauer@csgsystems.com

CSG SYSTEMS INTERNATIONAL, INC. REPORTS

SECOND QUARTER 2004 RESULTS

Revenues of $129.7 Million;

GAAP Net Income of $0.15 Per Diluted Share;

Earnings Reduced by $0.08 Per Diluted Share as a result of Early Debt Retirement

ENGLEWOOD, COLO. (July 27, 2004) — CSG Systems International, Inc. (Nasdaq: CSGS), a leading provider of customer care and billing solutions, today reported results for the quarter ended June 30, 2004.

Second Quarter 2004 Highlights:

• GAAP results were as follows: total revenues were $129.7 million; operating income was $22.0 million; and net income per diluted share was $0.15. Net income was reduced by $0.08 per diluted share as a result of the write-off of deferred financing costs related to CSG’s previous bank debt, which was repaid during the quarter.

• Cash flows from operations for the quarter ended June 30, 2004 were $40.2 million.

• CSG completed its offering of $230.0 million of 2.5% senior subordinated convertible contingent debt securities, and used a portion of the proceeds to retire its existing bank debt, and to repurchase 2.1 million shares of its common stock for $40.0 million ($18.72 per share).

• CSG’s Broadband Services Division (BSD) expanded its penetration of ancillary products and services within AdelphiaecTV, Mediacom, DirecTV and Time Warner. In addition, CSG signed a new five-year processing agreement with Adelphia Communications, which includes services related to Adelphia’s delivery of Voice over IP services. The bankruptcy court approved this agreement during the quarter.

• CSG’s Global Software Services Division (GSS) expanded its relationships with a number of customers including AT&T, BSNL, Casema, O2, GCI, British Telecom and Bellsouth Ecuador. In addition, CSG continued to expand its presence in China with the addition of two new customers—Sichuan Telecom and Shanghai Telecom.

• The Kenan FX business framework continued to gain momentum with six providers choosing to upgrade or implement the solution during the second quarter, bringing the total number of Kenan FX customers to 16. In addition, US LEC, a North American telecommunications carrier providing integrated voice, data and Internet services to businesses and enterprises in the Eastern United States, successfully deployed Kenan FX this quarter.

“We are continuing to see a stabilization in the telecommunications sector,” said Neal Hansen, chairman and chief executive officer of CSG Systems International, Inc. “Providers are looking for ways to increase their revenues and decrease their costs. In addition, our customers are successfully rolling out new services. As a result, there is an increased need for solutions that enable operators to bundle multiple products and services. We believe that we are well-positioned to benefit from this growing need.”

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CSG Systems International, Inc.

July 27, 2004

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Summary Results of Operations Information (unaudited)

(in thousands, except per share amounts and percentages):

	Three Months Ended June 30,						Six Months Ended June 30,
	2004		2003 (2)		Percent Change		2004		2003 (2)		Percent Change
Total revenues	$	129,663	$	142,361	(9	%)	$	260,027	$	284,293	(9	%)
Operating income		21,980		20,303	8	%		43,264		38,159	13	%
Net income		7,756		11,719	(34	%)		18,589		20,426	(9	%)
Net income per diluted share		0.15		0.23	(35	%)		0.36		0.40	(10	%)
Certain non-cash expenses (1):
Depreciation		3,517		4,334	(19	%)		7,153		8,933	(20	%)
Amortization		7,251		5,775	26	%		13,572		12,366	10	%
Stock-based employee compensation		3,800		1,414	169	%		7,945		2,709	193	%
Total	$	14,568	$	11,523	26	%	$	28,670	$	24,008	19	%

(1) These items are calculated in accordance with GAAP, and are reflected in the accompanying Condensed Consolidated Statements of Income and Cash Flows.

(2) During the fourth quarter of 2003, CSG adopted the fair value method of accounting for stock-based awards in accordance with SFAS No. 123, “Accounting for Stock-Based Compensation”, using the prospective method of transition. The adoption of SFAS No. 123 was effective as of January 1, 2003. As a result, CSG has restated its consolidated financial statements for the three and six months ended June 30, 2003 to reflect the inclusion of additional stock-based employee compensation expense of approximately $0.2 million and $0.3 million, respectively.

Second Quarter 2004 Results

Processing revenues for the second quarter of 2004 were $80.9 million, compared to $91.0 million for the same period last year and $81.1 million for the first quarter of 2004. The year-over-year quarterly reduction relates primarily to the lower revenues from Comcast as a result of the October 2003 arbitration ruling.

Software revenues decreased 33 percent year-over-year to $8.1 million, however increased six percent from the first quarter of 2004. Compared to the second quarter of last year, maintenance revenues increased four percent to $23.7 million, however, decreased six percent when compared to the first quarter of 2004. Professional services generated $17.0 million of revenue in the quarter, a four percent increase when compared to the same period last year and a three percent increase when compared to the first quarter of 2004.

Net income presented under generally accepted accounting principles (“GAAP”) for the second quarter of 2004 was $7.8 million, or $0.15 per diluted share. The second quarter results for 2004 were reduced by the write-off of deferred financing costs of $6.6 million (related to the retirement of CSG’s previously outstanding bank debt), and restructuring charges of approximately $0.1 million, or $0.08 per diluted share in total. GAAP net income for the second quarter of 2003 was $11.7 million, or $0.23 per diluted share. The second quarter 2003 results were reduced by approximately $1.0 million, or $0.01 per diluted share, due to restructuring charges.

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CSG Systems International, Inc.

July 27, 2004

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Divisional Results

CSG is organized into two divisions: the Broadband Services Division and the Global Software Services Division. CSG excludes its restructuring charges in the determination of its GAAP segment results. The results of operations for the divisions were as follows (in thousands, except percentages):

	Three Months Ended June 30, 2004
	Broadband Services Division			GSS Division			Corporate			Total
Processing revenues	$	80,278		$	617		$	—		$	80,895
Software revenues		935			7,174			—			8,109
Maintenance revenues		4,546			19,107			—			23,653
Professional services revenues		254			16,752			—			17,006
Total revenues		86,013			43,650			—			129,663
Segment operating expenses (3)		48,699			42,682			16,157			107,538
Contribution margin (loss) (3)	$	37,314		$	968		$	(16,157	)	$	22,125
Contribution margin percentage		43.4	%		2.2	%		N/A			17.1	%
	Three Months Ended June 30, 2003 (4)
	Broadband Services Division			GSS Division			Corporate			Total
Processing revenues	$	90,433		$	608		$	—		$	91,041
Software revenues		466			11,682			—			12,148
Maintenance revenues		5,079			17,749			—			22,828
Professional services revenues		212			16,132			—			16,344
Total revenues		96,190			46,171			—			142,361
Segment operating expenses (3)		53,448			48,213			19,404			121,065
Contribution margin (loss) (3)	$	42,742		$	(2,042	)	$	(19,404	)	$	21,296
Contribution margin (loss) percentage		44.5	%		(4.4	)%		N/A			15.0	%
	Six Months Ended June 30, 2004
	Broadband Services Division			GSS Division			Corporate			Total
Processing revenues	$	160,722		$	1,305		$	—		$	162,027
Software revenues		1,823			13,923			—			15,746
Maintenance revenues		9,673			39,031			—			48,704
Professional services revenues		398			33,152			—			33,550
Total revenues		172,616			87,411			—		$	260,027
Segment operating expenses (3)		97,954			85,251			31,262			214,467
Contribution margin (loss) (3)	$	74,662		$	2,160		$	(31,262	)	$	45,560
Contribution margin percentage		43.3	%		2.5	%		N/A			17.5	%

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CSG Systems International, Inc.

July 27, 2004

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	Six Months Ended June 30, 2003 (4)
	Broadband Services Division			GSS Division			Corporate			Total
Processing revenues	$	180,882		$	1,335		$	—		$	182,217
Software revenues		2,135			20,177			—			22,312
Maintenance revenues		10,108			35,123			—			45,231
Professional services revenues		582			33,951			—			34,533
Total revenues		193,707			90,586			—		$	284,293
Segment operating expenses (3)		105,083			99,535			37,364			241,982
Contribution margin (loss) (3)	$	88,624		$	(8,949	)	$	(37,364	)	$	42,311
Contribution margin (loss) percentage		45.8	%		(9.9	)%		N/A			14.9	%

(3) CSG’s segment operating expenses and contribution margin (loss), determined in accordance with GAAP, exclude restructuring charges of $0.1 million and $1.0 million, respectively, for the three months ended June 30, 2004 and 2003, and $2.3 million and $4.2 million, respectively, for the six months ended June 30, 2004 and 2003.

(4) The respective segment results have been restated for the three and six months ended June 30, 2003 to reflect the inclusion of additional stock-based compensation expense of approximately $0.2 million and $0.3 million, respectively, as a result of CSG’s adoption of SFAS No. 123, as discussed above.

Broadband Services Division

Total domestic customer accounts processed on CSG’s system as of June 30, 2004 were 43.7 million compared to 43.5 million as of March 31, 2004. The annualized revenue per processing unit for the second quarter of 2004 was $7.42 compared to annualized revenue per processing unit of $7.38 for the first quarter of 2004.

This quarter, CSG expanded its relationship with several clients including DirecTV, Mediacom and Time Warner. In addition, CSG signed a new five-year processing agreement with Adelphia that includes services related to Adelphia’s delivery of Voice over IP services, and helped Time Warner continue to rollout Voice over IP services in several markets, including Houston, Columbus and Cincinnati.

Global Software Services Division

The GSS Division expanded its relationship with existing customers as well as added new customers in the Asia Pacific region. Sichuan Telecom and Shanghai Telecom will be using the Kenan FX framework to support their subscribers in the Chinese market. This brings the total number of clients using Kenan FX framework to 16, including six additions during the second quarter.

Financial Condition

As of June 30, 2004, CSG had cash and short-term investments of $131.2 million, compared to $105.7 million as of March 31, 2004 and $105.4 million as of December 31, 2003. Billed net accounts receivable were $123.7 million as of June 30, 2004, compared to $137.6 million as of March 31, 2004 and $130.7 million as of December 31, 2003.

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CSG Systems International, Inc.

July 27, 2004

Page 5

Cash flows from operations for the quarter ended June 30, 2004 were $40.2 million, compared to $37.1 million for the same period in 2003, an increase of $3.1 million. Cash flows from operations for the quarter ended March 31, 2004 were $32.0 million, an increase of $8.2 million sequentially between quarters. The second quarter cash flows from operations of $40.2 million are significantly higher than our normal quarterly expectations, resulting primarily from the sale of certain pre-bankruptcy Adelphia accounts receivable to a third party, and higher than normal cash collections of accounts receivable within the GSS Division.

Convertible Debt Offering

In June 2004, CSG completed an offering of $230.0 million of 2.5% senior subordinated convertible contingent debt securities due June 15, 2024 in a private placement to qualified institutional buyers pursuant to exemptions from the registration requirements of the Securities Act of 1933. CSG used the proceeds from the debt securities, along with available cash, to: (i) repay the outstanding balance of its existing bank debt; (ii) repurchase 2.1 million shares of its common stock for $40.0 million; and (iii) pay debt issuance costs.

Stock Repurchase Program

Effective June 2, 2004, CSG’s Board of Directors increased the number of shares CSG is authorized to repurchase under its stock repurchase program by 5.0 million, to a total of 15.0 million shares. During the second quarter of 2004 (in conjunction with the convertible contingent debt offering) CSG repurchased 2.1 million shares of its common stock for $40.0 million ($18.72 per share). As of June 30, 2004, the total shares repurchased under CSG’s stock repurchase program since its inception in August 1999 totaled 8.5 million shares, at a total repurchase price of approximately $240 million (weighted-average price of $28.28 per share). At June 30, 2004, the total remaining number of shares authorized for repurchase under the program totaled 6.5 million shares.

Third Quarter and Full Year 2004 Financial Guidance

“For the third quarter, we are expecting revenues of between $126 million and $133 million and earnings per diluted share of between 19 and 24 cents,” Peter Kalan, chief financial officer, said.

“For fiscal year 2004, we remain comfortable with our revenue guidance of $515 million to $530 million,” Kalan added. “However, the anticipated accretion associated with the convertible debt offering is being negated due to increasing costs associated with the support of our clients rollout of new services and our continued expansion into new geographies. Therefore, our new full-year GAAP earnings per diluted share are expected to be between 77 cents and 87 cents. This reflects a one-time reduction of $0.08 in diluted earnings per share as a result of the second quarter write-off of deferred financing costs.

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CSG Systems International, Inc.

July 27, 2004

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“In addition, there are a number of non-cash items included in our earnings per share guidance,” Kalan said. “These non-cash items include amortization of approximately $27 million or 33 cents per diluted share, depreciation expense of approximately $14 million or 17 cents per diluted share, and stock-based employee compensation expense of approximately $15 million or 18 cents per diluted share. Our guidance does not include any restructuring charges that may be incurred beyond the second quarter of 2004 as we are not able to estimate them today.”

Conference Call

CSG will host a one-hour conference call on Tuesday, July 27, at 5 p.m. EDT, to discuss CSG’s second quarter results. The call will be carried live and archived on the Internet. A link to the conference call is available at www.csgsystems.com.

Additional Information

For additional information about CSG, please visit CSG’s web site at www.csgsystems.com. Additional information can be found in the Investor Relations section of the web site.

About CSG Systems International

Headquartered in Englewood, Colorado, CSG Systems International (NASDAQ: CSGS) is a leader in next-generation billing and customer care solutions for the cable television, direct broadcast satellite, advanced IP services, next generation mobile, and fixed wireline markets. CSG’s unique combination of proven and future-ready solutions, delivered in both outsourced and licensed formats, empowers its clients to deliver unparalleled customer service, improve operational efficiencies and rapidly bring new revenue-generating products to market. CSG is an S&P Midcap 400 company. For more information, visit our Web site at www.csgsystems.com.

This news release contains forward-looking statements as defined under the Securities Act of 1933, as amended, that are based on assumptions about a number of important factors and involve risks and uncertainties that could cause actual results to differ materially from what appears in this news release. These factors include, but are not limited to: 1) CSG’s ability to continue to perform satisfactorily and maintain good customer relations with its two largest customers, Comcast and Echostar Communications, which combined represent approximately 30 percent of the CSG’s revenue; 2) the continued acceptance of CSG CCS/BP, CSG Kenan FX and their related products and services; 3) CSG’s ability to enhance current products and develop new technology that will retain existing clients and capture new market share; 4) significant forays into new markets, which may prove costly and unprofitable; 5) the degree to which CSG’s expectations of market penetration and consumer acceptance of broadband, wireline and wireless services prove true — and even if realized, CSG’s ability to meet the billing and customer care needs of those markets; 6) client consolidation, which has decreased the number of potential buyers for many of CSG’s products and services; 7) CSG’s ability to expand and effectively operate its business internationally, which is much more complex and carries a higher collections risk; 8) CSG’s ability to renew software maintenance contracts and sell additional software products and services to existing and new clients, both domestically and internationally; 9) CSG’s ability to successfully deliver on lengthy and/or complex implementation projects, which by their nature, carry much more risk; and 10) any change in the accounting treatment as it relates to the determination of diluted shares outstanding for contingent convertible debt instruments, which could adversely impact our diluted earnings per share amounts. This list is not exhaustive and readers are encouraged to review the additional risks and important factors described in CSG’s reports on Forms 10-K and 10-Q and other filings made with the SEC.

FINANCIALS TO FOLLOW

CSG SYSTEMS INTERNATIONAL, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS-UNAUDITED

(in thousands, except share and per share amounts)

	June 30, 2004			December 31, 2003
ASSETS
Current assets:
Cash and cash equivalents	$	129,004		$	105,397
Short-term investments		2,197			—
Total cash, cash equivalents and short-term investments		131,201			105,397
Trade accounts receivable-
Billed, net of allowance of $6,942 and $11,145		123,720			130,691
Unbilled and other		13,756			18,042
Deferred income taxes		5,971			9,134
Income taxes receivable		4,353			35,076
Other current assets		12,000			11,697
Total current assets		291,001			310,037
Property and equipment, net of depreciation of $94,134 and $89,529		33,827			38,218
Software, net of amortization of $70,069 and $62,957		31,414			37,780
Goodwill		217,778			219,199
Client contracts, net of amortization of $56,143 and $50,973		52,772			57,458
Deferred income taxes		49,485			53,327
Other assets		8,893			8,756
Total assets	$	685,170		$	724,775
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Current maturities of long-term debt	$	—		$	45,137
Client deposits		19,317			17,175
Trade accounts payable		21,187			21,291
Accrued employee compensation		28,129			32,415
Deferred revenue		57,870			52,655
Income taxes payable		15,894			20,723
Arbitration charge payable		—			25,181
Other current liabilities		20,725			25,818
Total current liabilities		163,122			240,395
Non-current liabilities:
Long-term debt, net of current maturities		230,000			183,788
Deferred revenue		4,381			3,270
Other non-current liabilities		5,306			6,537
Total non-current liabilities		239,687			193,595
Stockholders’ equity:
Preferred stock, par value $.01 per share; 10,000,000 shares authorized; zero shares issued and outstanding		—			—
Common stock, par value $.01 per share; 100,000,000 shares authorized; 52,029,424 shares and 53,788,062 shares outstanding		597			593
Additional paid-in capital		292,721			281,784
Deferred employee compensation		(2,646	)		(4,458	)
Accumulated other comprehensive income:
Unrealized gain on short-term investments, net of tax		(2	)		1
Cumulative translation adjustments		6,755			6,519
Treasury stock, at cost, 7,636,496 shares and 5,499,796 shares		(211,110	)		(171,111	)
Accumulated earnings		196,046			177,457
Total stockholders’ equity		282,361			290,785
Total liabilities and stockholders’ equity	$	685,170		$	724,775

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CSG SYSTEMS INTERNATIONAL, INC.

CONDENSED CONSOLIDATED STATEMENTS OF INCOME-UNAUDITED

(in thousands, except per share amounts)

	Three Months Ended						Six Months Ended
	June 30, 2004			June 30, 2003			June 30, 2004			June 30, 2003
Revenues:
Processing and related services	$	80,895		$	91,041		$	162,027		$	182,217
Software		8,109			12,148			15,746			22,312
Maintenance		23,653			22,828			48,704			45,231
Professional services		17,006			16,344			33,550			34,533
Total revenues		129,663			142,361			260,027			284,293
Cost of revenues:
Cost of processing and related services		34,619			35,557			68,425			69,676
Cost of software and maintenance		17,162			17,395			33,436			35,705
Cost of professional services		15,616			14,673			29,766			33,228
Total cost of revenues		67,397			67,625			131,627			138,609
Gross margin (exclusive of depreciation)		62,266			74,736			128,400			145,684
Operating expenses:
Research and development		14,382			16,922			30,222			32,420
Selling, general and administrative		22,242			32,184			45,465			62,020
Depreciation		3,517			4,334			7,153			8,933
Restructuring charges		145			993			2,296			4,152
Total operating expenses		40,286			54,433			85,136			107,525
Operating income		21,980			20,303			43,264			38,159
Other income (expense):
Interest expense		(2,684	)		(3,482	)		(6,238	)		(7,356	)
Write-off of deferred financing costs		(6,569	)		—			(6,569	)		—
Interest and investment income, net		273			443			556			731
Other, net		(537	)		2,443			(1,050	)		2,829
Total other		(9,517	)		(596	)		(13,301	)		(3,796	)
Income before income taxes		12,463			19,707			29,963			34,363
Income tax provision		(4,707	)		(7,988	)		(11,374	)		(13,937	)
Net income	$	7,756		$	11,719		$	18,589		$	20,426
Basic net income per common share:
Net income available to common stockholders	$	0.15		$	0.23		$	0.36		$	0.40
Weighted average common shares		51,285			51,355			51,483			51,330
Diluted net income per common share:
Net income available to common stockholders	$	0.15		$	0.23		$	0.36		$	0.40
Weighted average common shares		52,096			51,656			52,175			51,570

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CSG SYSTEMS INTERNATIONAL, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS-UNAUDITED

(in thousands)

	Six Months Ended
	June 30, 2004			June 30, 2003
Cash flows from operating activities:
Net income	$	18,589		$	20,426
Adjustments to reconcile net income to net cash provided by operating activities—
Depreciation		7,153			8,933
Amortization		13,572			12,366
Restructuring charge for abandonment of facilities		595			683
Loss on short-term investments		3			—
Write-off of deferred financing costs		6,569			—
Deferred income taxes		7,046			1,958
Tax benefit of stock options exercised		423			9
Stock-based employee compensation		7,945			2,709
Changes in operating assets and liabilities:
Trade accounts and other receivables, net		11,654			(3,496	)
Other current and non-current assets		(401	)		(546	)
Arbitration charge payable		(25,181	)		—
Income taxes payable/receivable		27,454			481
Accounts payable and accrued liabilities		(9,064	)		(4,690	)
Deferred revenues		5,794			20,530
Net cash provided by operating activities		72,151			59,363
Cash flows from investing activities:
Purchases of property and equipment		(2,785	)		(2,920	)
Purchases of short-term investments		(6,813	)		(11	)
Proceeds from sale of short-term investments		4,610			—
Acquisition of businesses and assets, net of cash acquired		(852	)		(2,335	)
Acquisition of and investments in client contracts		(1,185	)		(1,030	)
Net cash used in investing activities		(7,025	)		(6,296	)
Cash flows from financing activities:
Proceeds from issuance of common stock		4,833			855
Repurchase of common stock		(40,448	)		—
Proceeds from long-term debt		230,000			—
Payments on long-term debt		(228,925	)		(21,075	)
Payments of deferred financing costs		(7,158	)		(87	)
Net cash used in financing activities		(41,698	)		(20,307	)
Effect of exchange rate fluctuations on cash		179			227
Net increase in cash and cash equivalents		23,607			32,987
Cash and cash equivalents, beginning of period		105,397			94,424
Cash and cash equivalents, end of period	$	129,004		$	127,411
Supplemental disclosures of cash flow information:
Cash paid (received) during the period for—
Interest	$	5,009		$	5,774
Income taxes		(25,172	)		9,625