MBU Croatia Licenses Key Components of ACI Commerce Framework to Enhance Card Operations; MBU Seeks Support from ACI Worldwide to Aid EMV Migration.

WATFORD, England -- ACI Worldwide (Nasdaq:TSAI), a leading international provider of enterprise e-payment solutions, announced today that MBU Ltd, a leading financial services provider in Croatia, has licensed key components of the ACI Commerce Framework to support its growing card operations business and enable the company to meet forthcoming EMV mandates. These components include ACI's flagship BASE24(R) software, the ACI Card Management System(TM) and ACI Smart Chip Manager(TM).

MBU was created by 27 Croatian banks in 1994 to develop a common bank card operations infrastructure. MBU designed, built and installed MBUNET, Croatia's leading ATM and POS terminal network. MBUNET will rely heavily on ACI's world-class BASE24 payments platform to provide transaction processing, authorisation and clearing for national and international bank cards including Visa, MasterCard and American Express. Deployment is underway and is expected to be completed by December 2004.

With EMV mandates fast approaching, MBU required support to ensure that its network of 540 ATMs and 2,700 POS terminals, as well as its card issuing system, complied with the January 2005 EMV deadline.

MBU selected ACI based on its unparalleled track record delivering electronic payment solutions, specifically for rapid EMV migration projects, and its positive experience with the ACI account team.

"MBU is committed to delivering a highly secure and quality service to its member banks through the use of progressive technology," said Sergio Uran, general manager at MBU Ltd. "ACI is the right technology partner to support our extensive requirements as we grow our business. The superiority of ACI's technology and the professionalism of their team helped us meet our goals within expected timeframes."

MBU licensed the ACI Card Management System to help members manage their cardholder base. Today MBU works with more than 17 banks and has issued more than one million cards. With new cards being issued at a rate of around 350,000 a year, MBU required sophisticated card issuance technology with the ability to maintain account information, track card usage and provide enhanced customer service.

The ACI Card Management System will also help MBU to clear EMV transactions and avoid reliance on internal processes and a bureau system. This will give MBU greater control and improve efficiencies. Its multi-currency module will also provide cross-border capabilities for MBU ATMs not based in Croatia. ACI Card Management System transfers card data to BASE24 to authorise debit transactions from ATM and POS devices.

ACI Smart Chip Manager will help MBU issue, manage and handle the data preparation for smart cards. Plastic cards are migrating from traditional magnetic stripe to chip, which enable multiple applications to be hosted on one card. ACI Smart Chip Manager will help MBU manage the life cycle of chip cards and update application parameters including EMV risk parameters in the field. It will also support personalisation of any smart card and the post-issuance of new applications to card schemes.

In addition, MBU licensed ACI's Automated Key Distribution System to automate and centralise the distribution of ATM secure numeric keys. By introducing an electronic method of managing and distributing keys, MBU can centralise this process to improve operational efficiency, reduce costs and improve ATM security.

"MBU has licensed numerous components within the ACI Commerce Framework, which will integrate with the new BASE24 deployment," said Richard Launder, managing director of ACI Worldwide (EMEA). "This provides MBU with an integrated approach to card operations, which will bring significant cost efficiencies and reduced exposure to risk as it responds to industry mandates including EMV."

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. Over 40 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 500 customers in 76 countries use ACI supplied software.

About MBU Ltd

MBU Ltd - IT engineering and interbank services - was established at the initiative of Croatian banks with the aim of coordinating the design and development of a common infrastructure for modern bank card operations. MBU has designed, built and started operating the MBNET system. MBNET entails a communication network for ATMs and EFTPOS terminals, a card acquiring and authorization system, a security system and a back office system for data exchange. In order to ensure simple, secure and quality service, MBU Ltd. has opted for the use of state-of-the-art technology and for those solutions which have been tested, certified and implemented by leading international card operating networks.

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 23, 2003, the Company's Form 10-Q filed on February 17, 2004, the Company's Form 10-Q filed on May 17, 2004, and the Company's Form 10-Q filed on August 11, 2004.