EXHIBIT 23 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement Nos. 333-64353, 333-04417, 333-28121, 333-34310, 333-34396 and 333-89957 on Form S-8; Registration Statement No. 333-44935 on Form S-4; and Registration Statement No. 333-74910 on Form S-3 of Fiserv, Inc. of our reports dated January 25, 2002, appearing in and incorporated by reference in this Annual Report on Form 10-K of Fiserv, Inc. for the year ended December 31, 2001. /s/ Deloitte & Touche LLP ---------------------- DELOITTE & TOUCHE LLP Milwaukee, Wisconsin February 26, 2002