Press Release

(New York – 10 September 2007) – ACI Worldwide (NASDAQ: ACIW) announced that they are collaborating with IBM to help customers plan and implement upgrades to their legacy payment systems to take advantage of the newest generation of application software from ACI. The company's BASE24-eps™ solution is the focus of the ACI/IBM efforts.

BASE24-eps was the subject of an IBM Redbook in 2006, providing detailed information about how the software is deployed on IBM's z/OS platform.  IBM has now published a supporting Redpaper that details the considerations to be taken into account by customers as they plan for when and how to undertake a migration to BASE24-eps as their engine for consumer payments processing.  

Financial institutions are under increasing pressure to upgrade legacy payment systems to keep pace with the growth in electronic payments volume, regulatory changes, and obsolescence of technology.  The combination of BASE24-eps on IBM System z offers a secure and powerful high-availability solution for supporting business growth while taking advantage of modern software architectures and the reliability and stability of IBM's hardware and software platform.  In addition, BASE24-eps complements ACI Payments Manager™ on System z to automate back office functions and leverage IBM’s virtualization strategy to lower operating cost. 

"BASE24-eps on System z provides a compelling offering for ACI customers," said Philip Heasley, president and CEO of ACI Worldwide, Inc.  "We continue to build momentum in our relationship with IBM, focused on providing gold-standard solutions to help our customers stay competitive.” 

June Yee Felix, general manager of banking solutions and strategy at IBM, said, "The combination of IBM and ACI is more important than ever to our clients as they work through major projects to transform their payments business.  Banks require payment systems that are integrated, open, flexible, scalable and secure. The Red-series publications will help joint customers take advantage of IBM and ACI technologies and skills to systematically renovate their payment systems, lower operating costs, and drive more value through this powerful combination.”

About IBM

For more information, please visit: www.ibm.com/partnerworld.

About ACI Worldwide

Every second of every day, ACI solutions are at work processing electronic payments, managing risk, automating back office systems and providing application infrastructure services.  Founded in 1975, ACI is a leading international provider of solutions for retail banking, wholesale banking 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 on the Internet at www.aciworldwide.com.

Any statements in this press release regarding projected results are preliminary and "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995.  In addition, this press release may contain other forward-looking statements including statements regarding ACI Worldwide Incorporated, its subsidiaries or third parties’ expectations, predictions, views, opportunities, plans, strategies, beliefs, and statements of similar effect.  The forward-looking statements in this press release are subject to a variety of risks and uncertainties.  Actual results could differ materially. 

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, and the Company’s Form 10-Q for the fiscal quarter ended March 31, 2007, filed on August 10, 2007.