Press Release

(Omaha, Neb. – 3 January 2006) – ACI Worldwide (Nasdaq: TSAI), a leading international provider of enterprise payment solutions, today announced survey results in which nearly three-fourths of business executives said they expect their organization to take steps toward the integration of retail and wholesale (consumer and corporate) payment systems in the next five years. A similar percentage said they expect to operate mission-critical applications on open systems platforms. The responses were gathered by payments software provider ACI Worldwide as part of its annual customer satisfaction survey. ACI clients include many of the world's largest banks, retailers and payment processors.

The trend toward convergence of payment systems is driven by banks' desire to lower the cost of payments processing, enhance service levels and 1:1 marketing, and improve risk management techniques. For some banks it may take the form of deploying a common authentication service across their enterprise. For others, it may involve an enterprise-wide routing function, or a service that electronically notifies retail and wholesale customers when particular events such as deposits or transfers impact their accounts. Industry analysts have observed that payments are a logical target for consolidation since they account for an estimated 40 percent of cost, revenues and operating income at many banks. 

ACI is unique among software providers in its ability to offer enterprise-wide payments solutions. The company's flagship consumer payments software, BASE24, processed more than 55 billion online payment transactions in 2005. At the same time, the market-leading ACI Wholesale Payments System (formerly known as iMTS) processed more than $1 trillion in high-value payments per day. These products are complemented by proven solutions for fraud detection, payments settlement and alerts notification as well as infrastructure solutions for connectivity, database management and business process management. 

Business executives in the ACI survey said they expect to operate mission-critical applications on open systems in order to achieve lower costs and the ability to reuse existing technology and skill sets in their organization. This is consistent with ACI's product strategy, which embraces an open systems approach to allow customers a choice of platforms. 

"Each year we survey our customers to measure their satisfaction with ACI's performance," said Jeff Hale, chief marketing officer of ACI Worldwide. "We also ask our primary business or executive contacts to give us feedback on key market trends. By listening to customers, we understand the goals of convergence and believe we have a unique ability to help clients capture efficiencies in payments processing and risk management by virtue of our enterprise-wide solutions. ACI has historically been known for the gold standard in payments software reliability. We've now brought that same reliability to an open systems environment and stand ready to deliver world-class solutions to customers as they increasingly adopt open systems for mission-critical payment applications."

The ACI survey was conducted in late 2005 by TNS Prognostics, a global leader in research-based consulting. Fifty-four percent of the survey's 387 respondents were based in the Americas, 36 percent in Europe, the Middle East and Africa, and 10 percent in Asia or the Pacific Rim. Ninety-five executive respondents provided information on the integration of retail and wholesale payment systems, and 100 provided information on the use of open systems platforms.

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 consumer and wholesale 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 on the Internet at www.aciworldwide.com.

Notes to editors

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 Transaction Systems Architects, Inc.’s (“TSA”), 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 and other risk factors, interested parties should review the Company's filings with the Securities and Exchange Commission, including the Company’s Form 10-K filed on December 14, 2005.