Postilion Self-Service Banking increases presence in credit union market

Norcross, Georgia – April 16, 2009 – Postilion, a division of S1 Corporation (NASDAQ: SONE) and a leading global provider of integrated solutions for self-service banking and payment processing, today announced the addition of several new credit union customers that have chosen Postilion Self-Service Banking to enable an integrated multi-channel approach to the technology and services they deploy:
• Cornerstone Financial Credit Union, Nashville, TN
• FirstLight Federal Credit Union, El Paso, TX
• generations federal credit union, San Antonio, TX
• Redwood Credit Union, Santa Rosa, CA

“We believe that credit unions traditionally have and will remain a source of strength during difficult financial times,” said Wes Barnett, CIO, generations federal credit union. “It is our very nature to provide the best possible financial services and solutions for our members. By utilizing Postilion’s integrated suite of self-service banking solutions, including, Postilion Retail Internet Banking with Personal Financial Management, Postilion ATM Driving, and Postilion Mobile, we are able to offer our members the highest quality products that allow them to successfully manage their finances, anytime, anywhere.”

Postilion’s Self-Service Banking solutions are designed to empower credit unions and community banks to deliver innovative, customer touch point solutions that level the playing field with larger financial institutions. Postilion solutions represent the next generation of integrated solutions for self-service banking, offering a comprehensive suite of tools. Financial institutions that initially license a single channel can further leverage their initial investment by turning on additional channels with limited effort, through basic configuration. Plus, the multi-channel-ready system ensures a consistent customer experience across all Postilion self-service channels, including ATM, business Internet banking, retail Internet banking, voice and mobile.

“While the current economic environment has put pressure on the greater financial services market, many credit unions are actually experiencing an increase in deposits and new member growth. As a result, credit unions are taking the opportunity to update their self-service banking solutions to strengthen member loyalty and attract new business,” said Pierre Naudé, President, Postilion Banking. “We are excited about the momentum that Postilion has gained in the credit union space and we will continue to focus on providing the solutions that enable both credit unions and community banks to deploy the most competitive functionality in the marketplace.”

About Postilion
Postilion, a division of S1 Corporation (NASDAQ: SONE), is a leading provider of integrated solutions for self-service banking and payment processing. Our offices, on five continents, serve over 1,500 customers in more than 50 countries. Postilion solutions drive self-service financial transactions and payments, including advanced transactions such as prepay, through Internet access points, ATMs, POS terminals, and phones.

More than 100,000 ATMs and 500,000 POS terminals worldwide run on Postilion solutions. In the United States, over 1,250 credit unions and community financial institutions use Postilion solutions. Built on open systems, Postilion solutions provide consolidated management information, card management, 3DES and EMV enablement, and loyalty management. At the forefront of compliance with new regulations and security enhancements, such as the Payment Card Industry Data Security Standard (PCI DSS) and Visa’s Payment Application Best Practices (PABP), Postilion can help customers achieve compliance with the latest data security standards developed by the payment card industry. More information is available at www.postilion.com.

About S1 Corporation
S1 Corporation (NASDAQ: SONE) delivers customer interaction software for financial and payment services and offers unique solution sets for financial institutions, retailers, and processors under three brand names: Postilion, S1 Enterprise and FSB Solutions. Additional information about S1 solutions is available at www.s1.com, www.postilion.com, www.S1enterprise.com, and www.fsb-solutions.com.

Forward-Looking Statements
This press release contains forward-looking statements within the safe harbor provisions of the Private Securities Litigation Reform Act. These statements include statements with respect to our financial condition, results of operations and business. The words “believes,” “expects,” “may,” “will,” “should,” “projects,” “contemplates,” “anticipates,” “forecasts,” “intends” or similar terminology identify forward-looking statements. These statements are based on our beliefs as well as assumptions made using information currently available to us. Because these statements reflect our current views concerning future events, they involve risks, uncertainties and assumptions. Therefore, actual results may differ significantly from the results discussed in the forward-looking statements. The risk factors included in our reports filed with the Securities and Exchange Commission (and available on our web site at www.s1.com or the SEC’s web site at www.sec.gov) provide examples of risks, uncertainties and events that may cause our actual results to differ materially from the expectations we describe in our forward-looking statements. Except as provided by law, we undertake no obligation to update any forward-looking statement.