EXHIBIT 99 PRESS RELEASE S1 CORPORATION ANNOUNCES DATE OF ANNUAL SHAREHOLDER MEETING ATLANTA, GA. - APRIL 19, 2002 -- S1 Corporation (NASDAQ: SONE), a leading global provider of Enterprise eFinance solutions, announced today that it will hold its Annual Shareholder Meeting on Thursday, May 23, 2002 at 8:30 a.m. EDT at the J.W. Marriott Hotel, 3300 Lenox Road NE, Atlanta, Georgia 30326. Holders of record of S1's common stock, Series D Convertible Preferred Stock and Series E Convertible Preferred Stock as of the close of business on April 19, 2002 will be entitled to vote at the meeting and will receive written notice of the meeting and copies of the proxy materials. ABOUT S1 CORPORATION S1 (NASDAQ: SONE) is a leading global provider to more than 3,700 banks, credit unions, insurance providers, and investment firms of enterprise software solutions that turn customer interactions into profits. S1's Enterprise eFinance solutions deliver a transactionable, customer-centric view across all delivery channels, resulting in a more compelling experience for the customers and a more profitable relationship for the financial institution. S1 is the only eFinance provider with the proven experience, breadth of products, and financial strength to empower financial services companies' Enterprise eFinance strategy. Additional information about S1 is available at www.s1.com. CONTACT: Sterling Hager, Inc. for S1 Corporation Tracey Frederickson 617-926-6665 ext. 241 tfrederickson@sterlinghager.com or Investor Relations for S1 Corporation Nancy O'Donnell 404-923-3500 nancy.odonnell@s1.com