EXHIBIT 23.1


                       CONSENT OF INDEPENDENT ACCOUNTANTS


We hereby consent to the incorporation by reference in the Registration
Statements on Form S-8 (No. 333-72250), Form S-8 (No. 333-37062), Form S-8 (No.
333-43370), Form S-8 (No. 333-43372), Form S-8 (No. 333-43376), Form S-8 (No.
333-45766), Form S-8 (No. 333-82369), Form S-8 (No. 333-82383), Form S-8 (No.
333-82381), Form S-8 (No. 333-82711), Form S-3, as amended (No. 333-75178) and
Form S-3 (No. 333-36470) of S1 Corporation of our report dated March 21, 2002,
relating to the financial statements and financial statement schedule of S1
Corporation as of December 31, 2000 and 2001 and for each of the three years in
the period ended December 31, 2001, which appears in this Form 10-K.



PricewaterhouseCoopers LLP
Atlanta, Georgia
April 1, 2002