ACI Worldwide's WinPayment Solution Achieves ClusterProven Status From IBM.

Business Editors & Technology Writers

OMAHA, Neb.--(BUSINESS WIRE)--June 26, 2001

ACI Worldwide (Nasdaq:TSAI), a leading international provider of enterprise e-payment solutions, announces that its retail payments software, WinPayment(R), has been validated by IBM(R) as ClusterProven(TM).

The IBM ClusterProven program is designed to encourage the development of solutions that meet carefully defined technical and functional requirements for delivering the utmost in availability and scalability. The ClusterProven validation indicates that a solution has availability and scalability characteristics beyond those achieved on a single server node to help maintain application availability in the event of a failure. IBM assists developers who wish to validate their solutions as ClusterProven.

WinPayment provides retailers with a fast, convenient software system for processing debit and credit card transactions. The system operates on the Microsoft(R) Windows platform and supports interfaces to leading EFT software providers, major point-of-sale systems, authorization networks and settlement institutions.

"WinPayment delivers a unique blend of performance, scalability, and flexibility on the reliable, easy-to-manage IBM eServer xSeries," said Mark Vipond, president of ACI Worldwide. "IBM's continued recognition of our solutions is another validation of our commitment to deliver best-of-breed e-payment solutions on IBM platforms."

IBM's X-architecture(TM) initiative brings high-end server technologies developed by IBM to its eServer xSeries Intel(R)-based server line. X-architecture differentiates xSeries servers with technologies that make e-business perform quickly, and with great scalability and reliability. This move is another important step in IBM's strategy of disseminating the company's best technology throughout the IBM eServer line.

IBM recently validated ACI's OCM24(R) retail banking payments application as Advanced ClusterProven and ServerProven(R). Together, ACI and IBM offer a full range of products and services to support large-scale transaction processing and e-business.

About ACI Worldwide

Every second of every day, consumers are initiating electronic payment transactions--getting cash at ATMs, using debit and credit cards to make purchases in stores and on the Internet, banking by phone and PC, paying bills online. Twenty billion times a year, ACI software is used to process these transactions, powering the world's online payment systems. ACI was founded in 1975 and pioneered the development of applications and networking software for online transaction processing. Today more than 2,000 customers in 78 countries use ACI supplied software. Visit ACI Worldwide on the Internet at www.aciworldwide.com.

The IBM eServer brand consists of the established IBM e-business logo with the descriptive term "server" following it.

IBM, the e-business logo, ServerProven, ClusterProven, X-architecture and xSeries are trademarks of IBM Corporation. Intel is a registered trademark of Intel Corporation 

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. Factors that could cause actual results to differ include but are not limited to the following.

The success of TSA, or any of its subsidiaries, entering into a new distribution or partnering arrangement depends on numerous factors including the acceptance of the distributed products or services by TSA's existing customer base and integration of the products and services into TSA's marketing efforts, the quality of the products or services as perceived after use by TSA's customers, and the degree of competition from competitive products or service providers.

TSA's business is concentrated in the banking industry, making it susceptible to a downturn in that industry.

TSA is subject to risks of conducting international operations including: difficulties in staffing and management, reliance on independent distributors, fluctuations in foreign currency exchange rates, compliance with foreign regulatory requirements, variability of foreign economic conditions, and changing restrictions imposed by U.S. export laws.

Fluctuations in quarterly operating results may result in volatility in TSA's stock price. No assurance can be given that operating results will not vary. TSA's stock price may also be volatile, in part due to external factors such as announcements by third parties or competitors, inherent volatility in the high-technology sector and changing market conditions in the industry.

For a detailed discussion of these and other risk factors, interested parties should review TSA's filings with the Securities and Exchange Commission, including Exhibit 99.01 to TSA's Annual Report on Form 10-K for the fiscal year ended September 30, 2000.