ACI Worldwide, Inc. to File Its Form 10-K the Week of January 28, 2008

NEW YORK, Jan. 22, 2008 (PRIME NEWSWIRE) -- ACI Worldwide, Inc. (Nasdaq:ACIW)
(the "Company") today announced that it has completed its previously announced
review of certain tax deductions taken in U.S. federal income returns for the
years ended September 30, 2004, 2005 and 2006 and has concluded that previously
filed financial statements will not require adjustment.

With the completion of this review, the Company intends to file its Annual
Report on Form 10-K for the fiscal year ended September 30, 2007 during the week
of January 28, 2008.

About ACI Worldwide, Inc.

The Company's software facilitates electronic payments by providing consumers
and companies access to their money. Its products are used to process
transactions involving credit cards, debit cards, mobile commerce, smart cards,
checks, high-value money transfers, bulk payment clearing and settlement, and
enterprise e-infrastructure. The Company's solutions are used in more than 2,050
product systems in 84 countries on six continents. Visit ACI Worldwide, Inc. on
the Internet at www.aciworldwide.com.

Forward-Looking Statements

This press release contains forward-looking statements based on current
expectations that involve a number of risks and uncertainties. Generally,
forward-looking statements do not relate strictly to historical or current facts
and may include words or phrases such as the Company "believes," "will,"
"expects," "looks forward to," and words and phrases of similar impact. The
forward-looking statements are made pursuant to safe harbor provisions of the
Private Securities Litigation Reform Act of 1995. Forward-looking statements in
this press release include, but are not limited to, statements regarding the
Company's expected timing for the filing of its Annual Report on Form 10-K for
the year ended September 30, 2007.

Any or all of the forward-looking statements may turn out to be wrong. They can
be affected by the judgments and estimates underlying such assumptions or by
known or unknown risks and uncertainties. These factors include, without
limitation, (i) the risk that additional information may arise from the
preparation of the Company's financial statements, including the completion of
the Company's FIN 48 review, or other subsequent events that would require the
Company to make adjustments to its financials statements and thereby impact the
Company's timing with respect to filing its annual report and (ii) the risk that
significant judgment is required in determining the Company's worldwide income
tax liabilities and other tax liabilities and that governing tax authorities may
have different interpretations of applicable law and, as a result, may attempt
to challenge the Company's tax positions set out in its financial statements
which, if successful, could adversely affect the Company's financial condition
and/or results of operations. Consequently, no forward-looking statement can be
guaranteed. In addition, the Company disclaims any obligation to update any
forward-looking statements after the date of this release.

All of the foregoing forward-looking statements are expressly qualified by the
risk factors discussed in the Company's filings with the Securities and Exchange
Commission. For a detailed discussion of these risk factors, parties that are
relying on the forward-looking statements should review the Company's filings
with the Securities and Exchange Commission, including the Company's Form 10-K
filed on May 11, 2007, the Company's Form 10-Q for the fiscal quarter ended
December 31, 2006 filed on June 29, 2007, the Company's Form 10-Q for the fiscal
quarter ended March 31, 2007 filed on August 10, 2007, and the Company's Form
10-Q filed on September 25, 2007 respectively and specifically the sections
entitled "Factors That May Affect the Company's Future Results or the Market
Price of the Company's Common Stock."

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CONTACT: ACI Worldwide, Inc.
Investor contact:
Tamar Gerber, Vice President, Investor Relations
646-348-6706