Press Release

KEY QUARTERLY HIGHLIGHTS

Generated strong operating free cash flow of $11.7 million versus $2.3 million
in June 2006 quarter.
Continued sequential growth of $26 million in 60-month backlog to $1.270 billion versus $1.244 billion in the March quarter of 2007.
Signed a multi product contract with a large European bank to install BASE24-eps™ , ACI Proactive Risk Manager debit and credit on the IBM Z-Series platform and also expanded our direct distribution network in Asia with the acquisition of Stratasoft Sdn Bhd.

(NEW YORK — September 20, 2007) — ACI Worldwide, Inc. (NASDAQ:ACIW), a leading international provider of software for electronic payment systems, today announced financial results for the period ending June 30, 2007. We will hold a conference call on September 20, 2007 at 8:30 am EDT to discuss this information. Interested persons may also access a real-time audio broadcast of the teleconference at http://www.aciworldwide.com/investors.

“We believe that the continued growth in operating free cash flow underscores our effort to build and deliver long-term economic value in our business,” stated Chief Executive Officer Philip G. Heasley. “Our results in the June quarter demonstrated the progress of our strategic emphasis upon cross-selling products to our existing accounts and we were encouraged by the growth of multi-product users within the quarter. In the March and June quarterly results, we demonstrated growth in both our backlog and in our deferred revenue compared to last year. In pursuit of the growth and expansion of our Asian direct distribution network we purchased Stratasoft in Malaysia, a long time ACI partner.”

Notable new business during the quarter included:

• A multi-product contract signed with a bank in Brazil for ACI Proactive Risk Manager, and ACI Automated Case Management systems. 
• BASE24-eps™ capacity contract signed with a top 40 global bank.
• Seven new customers signed; including new users of ACI Enterprise Banker On Demand and of Proactive Risk Manager.
• Thirty one new applications added to existing customer relationships ranging from ACI Retail Commerce Server to PRM Enterprise Risk and Simulation Services for Enterprise Testing.

FINANCIAL SUMMARY

Operating Free Cash Flow
Operating free cash flow was $11.7 million compared to $2.3 million for the June 2006 quarter. The drivers of our operating free cash flow were solid contracting, billings and collections.

Backlog
As of June 30, 2007, our estimated 60-month backlog was $1.270 billion, compared to $1.244 billion as of March 31, 2007 and compared to $1.078 billion as of June 30, 2006. As of June 30, 2007, our 12-month backlog was $317 million, as compared to $307 million for the quarter ended March 31, 2007 and $257 million for the quarter ended June 30, 2006. The sequential growth of $26 million in our 60-month backlog was comprised of ACI organic growth of $23 million and $3 million from our acquired companies.

Revenues
Revenue was $98.1 million in the quarter ended June 2007, an increase of $13.3 million or 16 percent over the prior year period revenue of $84.8 million. $13.0 million of the increase was due to acquired companies’ revenue while $0.3 million was attributable to ACI’s organic business. Sequentially, our deferred revenue increased slightly at $1.1 million compared to a sequential decrease of $5.2 million in the June 2006 quarter, reflecting the business’ emphasis on selling longer term products and services to both new and existing customers, thus resulting in lengthier revenue recognition cycles.

Operating Expenses
Excluding expenses of $15.5 million related to acquisitions, $4.7 million related to the review of historical stock option practices and vested share option settlement, and $1.3 million related to non-recurring employee costs, organic operating expenses for the quarter rose $2.5 million on a year over year basis. The rise in operating expense was primarily driven by a $1.4 million swing in deferred expenses and $0.7 million related to investments in Ireland and in Romania. Including the impact of these items, operating expenses were $93.2 million in the June 2007 quarter compared to $69.2 million in the June 2006 quarter.

Other Income and Expense
Other expense for the quarter was $2.0 million, compared to other income of $1.4 million in the June 2006 quarter. The decrease in other income resulted from the following factors: a loss on foreign exchange, a reduction of cash and cash equivalents due to the funding of the share repurchase program which also impacted interest income received, and interest expense paid on the outstanding credit facility.

Taxes
The elongation of our revenue recognition cycle, combined with several non-recurring charges, has resulted in lower pre-tax earnings. The impact of the $0.5 million fixed charge related to the transfer of intellectual property rights to Ireland and our geographic profit mix combined with the lower pretax earnings led to an effective tax rate of 195 percent for the period ending June 30, 2007. The equivalent period ending June 30, 2006 had a rate of (33.1) percent due to a $12.6 million tax benefit related to the release of valuation allowances during the quarter.

Net Income (Loss) and Diluted Earnings Per Share
Net loss for the quarter was $2.7 million, compared to net income of $22.5 million during the same period last year. Earnings per share for the quarter ended June 2007 was $(0.07) per diluted share compared to $0.59 per diluted share during the same period last year. The year-over-year quarterly variance is primarily due to the following factors: change in tax rate $(0.48), dilutive impact of acquisitions $(0.04), expense related to the review of historical stock options and expense related to the settlement of vested options $(0.08), employee related costs $(0.02), investment in global offices and change in deferred costs $(0.03).

Shares Outstanding
Total weighted average diluted shares outstanding were 37.1 million as of June 30, 2007 as compared to 38.5 million shares outstanding as of June 30, 2006. Shares repurchased in the quarter totaled 463,100 shares at an average price of $33.90 or $15.7 million. Year to date we have repurchased 1,373,720 shares at an average price of $30.41.

Adjusted Non-GAAP Earnings Per Share
Adjusted Non-GAAP earnings for the quarter were $0.10 per diluted share, compared to $0.31 per diluted share during the same period last year. The variance is due primarily to the following factors: variance in taxes paid $(0.16), investment in Ireland and in Romania and change in deferred costs $(0.03).

Calendar Year Guidance Update
We have modified our assumptions on calendar year guidance predicated on the performance of the operating business as well as the impact of all expenses related to the options review charge of $4.7 million and non-recurring employee exit costs of approximately $6.5 to $7.5 million. Operating free cash flow is expected to be in the range of $50 million to $55 million with 60-month backlog of $1.290 billion to $1.310 billion. Revenue for calendar year 2007 is expected to be in the range of $390 million to $400 million. Currently we anticipate GAAP earnings per share for calendar year 2007 to be $0.20 to $0.40 per fully diluted share. Non-GAAP earnings per share, adjusted by adding expenses associated with amortization of intangible assets from acquisitions and non-cash, stock-based compensation (see Adjusted Non-GAAP Financial Measure below), is expected to be $0.82 to $1.02. In estimating earnings per share guidance for calendar 2007, we assume an average effective tax rate of 37 percent and 37.4 million shares outstanding.

About ACI Worldwide, Inc.

Every second of every day, ACI Worldwide solutions are at work processing electronic payments, managing risk, automating back office systems and providing application infrastructure services. ACI is a leading international provider of solutions for banking, retail and cross-industry systems. ACI serves more than 800 customers in 84 countries including many of the world's largest financial institutions, retailers and payment processors. Visit ACI Worldwide at http://www.aciworldwide.com/.

Non GAAP Financial Measures
This press release includes operating free cash flow, and earnings per share on an adjusted, non-GAAP basis. ACI is presenting these non-GAAP guidance measures to provide more transparency to its earnings, focusing on operations before selected non-cash items, operating free cash flow. We believe that providing earnings per share on an adjusted, non-GAAP basis is useful to our investors as an operating measure because it allows investors to more accurately compare our ongoing performance from period to period. However, earnings per share on an adjusted non-GAAP basis, is limited because it excludes expenses associated with amortization of intangible assets from acquisitions and non-cash stock based compensation. ACI is also presenting operating free cash flow, which is defined by our net cash provided by operating activities, adjusted for one-time items, minus capital expenditures. We utilize this non-GAAP financial measure, and believe it is useful to investors, as an indicator of cash flow available for debt repayment and other investing activities, such as capital investments and acquisitions. We utilize operating free cash flow as a further indicator of operating performance and for planning investing activities. A limitation of operating free cash flow is that it does not represent the total increase or decrease in the cash balance for the period. This measure also does not exclude mandatory debt service obligations and therefore does not represent the residual cash flow available for discretionary expenditures.

Management generally compensates for limitations in the use of non-GAAP financial measures by relying on comparable GAAP financial measures and providing investors with a reconciliation of the non-GAAP financial measures only in addition to and in conjunction with results presented in accordance with GAAP. We believe that these non-GAAP financial measures reflect an additional way of viewing aspects of our operations that, when viewed with our GAAP results, provide a more complete understanding of factors and trends affecting our business. These non-GAAP measures should be considered as a supplement to, and not a substitute for, or superior to, loss from operations and net loss per share calculated in accordance with GAAP. Due to the forward-looking nature of free operating cash flows and earnings per share on an adjusted, non-GAAP basis for future periods, information to reconcile such non-GAAP financial measures to the most directly comparable GAAP financial measure is not available at this time as the Company is unable to forecast any special items for future periods.