Consent of Independent Public Accountants

     As independent public  accountants,  we hereby consent to the incorporation
by  reference  in this Form S-8  Registration  Statement  of our  reports  dated
October 29, 1998,  included in  Transaction  Systems  Architects,  Inc.'s Annual
Report on Form 10-K for the fiscal  year  ended  September  30,  1998 and to all
references to our Firm included in this Registration Statement.

                                                             Arthur Andersen LLP

Omaha, Nebraska,
   February 24, 1999