VIENNA, Austria and NORCROSS, Georgia, September 16 /PRNewswire/ --

S1 Enterprise, a division of S1 Corporation (Nasdaq: SONE) and a leading
provider of multichannel financial services software, today announced the
incorporation of International ACH Transaction (IAT) capabilities in its S1
Corporate Banking solution. In accordance with NACHA's latest directive that
"strongly encourages" banks to have IAT implemented by March 20, 2009, S1
Corporate Banking customers have the opportunity to take advantage of early
preparation for testing with ACH operators, interfacing with OFAC screening
systems, and customer education.

IAT, the newest ACH Standard Entry Class (SEC) code, will replace S1
Corporate Banking's existing consumer and corporate cross border payment
types. According to Aite Group, IAT will provide the means to fully automate
international ACH processing, ensuring regulatory compliance while fostering
the ability to transact globally.

"IAT is the result of a combination of forces - stronger focus on
regulatory issues along with the expansion of a global economy that demands
more and more international transaction capabilities," said Nancy Atkinson,
Senior Analyst, Aite Group. "This necessitates a change to existing SEC codes
in order to keep up with the growing number of international ACH payments
while thwarting the money laundering risk potential."

"We serve many of the largest U.S. banks who rely on S1 to deliver major
updates like IAT early so that they have adequate time to install and test
these regulatory changes." said Fred Dumas, General Manager, S1 Enterprise
Treasury Online Group. "Our philosophy is to exceed our customer's
expectations, provide them with a competitive advantage in the markets they
serve, and win high marks in customer satisfaction."

S1 has almost twenty years of experience providing cash management
solutions to the world's largest banks. S1 Corporate Banking provides an
integrated global payments framework supporting diverse domestic and
international payments, including wire transfers, account transfers, ACH and
localized payments for over twenty countries. In addition to comprehensive
payment services, S1 Corporate Banking offers a rich, highly flexible
user-interface, extensive security and entitlement features like multi-factor
authentication, bulk file transfers, check services, and complete information
reporting functionality.

About S1 Enterprise

More than 100 banks and three million consumer, small business, and
corporate users worldwide rely on S1 Enterprise solutions to access and
manage their financial information. A division of S1 Corporation (Nasdaq:
SONE), S1 Enterprise is a leading provider of integrated banking solutions
that enables financial service providers to receive a holistic view of their
customer via a common technology platform regardless of delivery channel -
branch, call center, Internet, or voice. Additional information about S1
Enterprise is available at www.s1enterprise.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.

Web site: http://www.s1.com
              http://www.s1enterprise.com
              http://www.postilion.com
              http://www.fsb-solutions.com