As filed with the Securities and Exchange Commission on April 11, 2002

                                              Registration No. 333-_____________


                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-3
             Registration Statement Under The Securities Act of 1933
                        --------------------------------

                      TRANSACTION SYSTEMS ARCHITECTS, INC.
              (Exact name of registrant as specified in its charter)

             Delaware                                            47-0772104
 (State or other jurisdiction of                              (I.R.S. Employer
  incorporation or organization)                             Identification No.)

                             224 South 108th Avenue
                              Omaha, Nebraska 68154
                                 (402) 334-5101
               (Address, including zip code, and telephone number,
        including area code, of registrant's principal executive offices)

                              David P. Stokes, Esq.
                          General Counsel and Secretary
                      Transaction Systems Architects, Inc.
                             224 South 108th Avenue
                              Omaha, Nebraska 68514
                                 (402) 334-5101
            (Name, address, including zip code, and telephone number,
                    including area code, of agent for service)

                                    Copy to:
                             Albert G. McGrath, Jr.
                                Baker & McKenzie
                            2300 Trammell Crow Center
                                2001 Ross Avenue
                               Dallas, Texas 75201
                                 (214) 978-3000

        Approximate date of commencement of proposed sale to the public:
   from time to time after the effective date of this registration statement.

     If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the following
box. |_|

     If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box. |X|

     If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following box
and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. |_|

     If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. |_|

     If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. |_|



                         CALCULATION OF REGISTRATION FEE
                                                                                                  
================================================= ================== ==================== ==================== ==============
                                                                       Proposed maximum     Proposed maximum      Amount of
        Title of each class of securities               Amount        offering price per   aggregate offering   registration
                to be registered                   to be registered        unit (1)            price (1)             fee
------------------------------------------------- ------------------ -------------------- -------------------- --------------
 Class A Common Stock, par value $.005 per share    100,000 shares          $11.12             $1,112,000          $102.30
================================================= ================== ==================== ==================== ==============
(1)  Estimated solely for purposes of calculating the registration fee pursuant
     to Rule 457(c) promulgated under the Securities Act of 1933, as amended.
     The price is based upon the average of the high and low prices of
     Transaction Systems Architects, Inc. Class A Common Stock on April 10,
     2002, as reported on the Nasdaq National Market.
                         -------------------------------


The registrant hereby amends this registration statement on such date or dates
as may be necessary to delay its effective date until the registrant shall file
a further amendment which specifically states that this registration statement
shall thereafter become effective in accordance with Section 8(a) of the
Securities Act of 1933 or until the registration statement shall become
effective on such date as the Commission, acting pursuant to said Section 8(a),
may determine.






The information in this prospectus is not complete and may be changed. We may
not sell these securities until the registration statement filed with the
Securities and Exchange Commission is effective. This prospectus is not an offer
to sell these securities and it is not soliciting an offer to buy these
securities in any state where the offer or sale is not permitted.


                   Subject to completion, dated April 10, 2002


                                   PROSPECTUS


                                 100,000 Shares
                      Transaction Systems Architects, Inc.
                              Class A Common Stock

                           -------------------------

     This prospectus relates to the sale of up to 100,000 shares of our Class A
Common Stock, which may be offered for sale by the selling stockholders
described in this prospectus. The shares offered by this prospectus are issuable
upon the exchange or redemption of shares of non-voting preferred stock that
were previously issued to the selling stockholders by TSA Exchangeco Limited,
one of our wholly-owned subsidiaries. The shares of Class A Common Stock to
which this prospectus relates may be sold from time to time by the selling
stockholders directly or through one or more broker-dealers, in one or more
transactions on the Nasdaq National Market, in the over-the-counter market, in
negotiated transactions or otherwise, at prices related to the prevailing market
prices or at negotiated prices. We will not receive any of the proceeds from the
sale of the shares of Class A Common Stock sold by the selling stockholders.

     Our Class A Common Stock is listed on the Nasdaq National Market under the
symbol "TSAI." The closing market price of our Class A Common Stock on April 10,
2002 was $11.56 per share. Our principal executive offices are located at 224
South 108th Avenue, Omaha, Nebraska 68154, and our telephone number is (402)
334-5101.

                              -------------------

     You should consider carefully the "Risk Factors" beginning on page 3 before
making a decision to purchase shares of Class A Common Stock.

                              -------------------

     Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or passed upon the
adequacy or accuracy of this prospectus. Any representation to the contrary is a
criminal offense.

                              --------------------

                The date of this prospectus is ________ __, 2002.






                                TABLE OF CONTENTS
                                                                            Page

FORWARD-LOOKING STATEMENTS................................................... 3

RISK FACTORS................................................................. 3

THE COMPANY.................................................................. 4

WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE.............. 5

USE OF PROCEEDS.............................................................. 5

DESCRIPTION OF TSA CAPITAL STOCK............................................. 5

SELLING STOCKHOLDERS......................................................... 7

PLAN OF DISTRIBUTION......................................................... 8

LEGAL MATTERS................................................................ 9

EXPERTS...................................................................... 9


You should rely only on the information provided in this prospectus or
incorporated into it by reference. No person has been authorized to provide you
with different information. We are not making an offer of these securities in
any state where the offer is not permitted. Information is accurate only as of
the date of the documents containing the information, unless the information
specifically indicates that another date applies.



                                      2



                           FORWARD-LOOKING STATEMENTS

     This prospectus and the documents we incorporate by reference may contain
"forward-looking statements" within the meaning of the Private Securities
Litigation Reform Act of 1995, all of which are subject to risks, uncertainties
and assumptions. We believe that such statements are accompanied by meaningful
cautionary statements, so as to ensure to the fullest extent possible the
protections of the safe harbor established in the Private Securities Litigation
Reform Act. Statements other than statements of existing or historical fact we
make in this prospectus or the documents we incorporate by reference are
forward-looking. Words such as "anticipates," "expects," "intends," "plans,"
"believes," "seeks," "estimates," "forecasts," "projects," and similar
expressions identify forward-looking statements. However, the absence of these
words does not mean a statement is not forward-looking. Actual results may
differ materially from those in forward-looking statements due to many factors,
including those set forth below in "Risk Factors" or in documents we incorporate
by reference. We operate in a rapidly changing and evolving business involving
electronic commerce and payments and new risk factors will likely emerge. We
cannot predict or identify all significant risk factors.

                                  RISK FACTORS

     In addition to the other information in this prospectus and information
incorporated by reference, you should carefully consider the following factors
in evaluating your decision to purchase shares of our Class A Common Stock.

We are subject to risks of international operations

     We will continue to derive a majority of our total revenue from
international operations and are subject to risks of conducting international
operations including: difficulties in staffing and management, reliance on
independent distributors, longer payment cycles, volatilities of foreign
currency exchange rates, compliance with foreign regulatory requirements,
variability of foreign economic conditions, and changing restrictions imposed by
U.S. export laws.

We are dependent upon a single family of products

     We will continue to derive a substantial majority of our total revenue from
licensing our BASE24 family of software products and providing services and
maintenance related to those products. Any reduction in demand for, or increase
in competition with respect to, BASE24 products would have a material adverse
effect on our financial condition and results of operations.

We are dependent upon the demand for Compaq computers

     We will continue to derive a substantial portion of our revenues from
licensing of software products that operate on Compaq computers. Any reduction
in demand for these computers or in Compaq's ability to deliver products on a
timely basis could have a material adverse effect on our financial condition and
results of operations. Compaq has announced that it is planning to consolidate
its high-end performance enterprise servers on the Intel Corp. Itanium
microprocessor by 2004. Also, Compaq is in the process of completing a merger
with Hewlett-Packard Co. We have not determined whether the consolidation of the
high-end servers, if it occurs as announced, or the merger, if consummated,
would materially affect our business, financial position or results of
operation.

We are dependent upon the banking industry

     Our business is concentrated in the banking industry, making it susceptible
to a downturn in that industry. Further, banks are continuing to consolidate,
decreasing the overall number of potential buyers of our products and services.

We are subject to the uncertainties of new accounting standards

     New accounting standards, or additional interpretations or guidance
regarding existing standards, could be issued in the future, which could lead to
unanticipated changes in our current financial accounting policies. These
changes could affect the timing of revenue or expense recognition and cause
fluctuations in operating results.

                                       3


Continuing net operating losses could adversely affect our stock price

     We have experienced net operating losses with respect to each of the prior
five fiscal quarters. No assurances can be given regarding future operating
results. Our stock price may be adversely affected by future net operating
losses. Our stock price may also be affected by external factors such as
announcements by competitors or third parties, inherent volatility in the
high-technology sector and changing market conditions in the industry.

We may not be able to expand successfully through acquisitions

     We have expanded and may seek to continue to expand our operations through
the acquisition of additional businesses. Acquisitions involve many risks that
could have a material adverse effect on our business, financial condition and
results of operations. Management's negotiations of potential acquisitions and
the integration of acquired businesses or technologies could divert their time
and resources. Further, we may not be able to properly integrate acquired
businesses or technology with our existing operations, train and motivate
personnel from the acquired business, or combine potentially different corporate
cultures.

                                   THE COMPANY

     We develop, market, install and support a broad line of software products
and services primarily focused on facilitating electronic payments and
electronic commerce. In addition to our own products, we distribute or act as a
sales agent for software developed by third parties. The products and services
are used principally by financial institutions, retailers and e-payment
processors, both in domestic and international markets. Our products and
services are organized into the following business units: (1) ACI Worldwide, (2)
Insession Technologies and (3) IntraNet, Inc.

     ACI Worldwide. Products in this business unit represent our largest product
line and include our most mature and well-established applications. Within this
business unit are three primary software product suites -- Payment Engines,
Secure Commerce and Payments Management. The Payment Engines suite includes our
BASE24, Enterprise Payment System, WINPAY24 and NET24 applications. The Secure
Commerce suite includes our e-Courier and e-Courier for Billing delivery
solutions, Virtual Wallet, Commerce Gateway and Chip Card Manager applications.
The Payments Management suite includes our Proactive Risk Manager and a variety
of other payments management solutions.

     Financial institutions, retailers and e-payment processors use our products
to route and process transactions for Automated Teller Machine networks; process
transactions from traditional Point-of-Sale devices, wireless devices and the
Internet; handle PC and phone banking transactions; control fraud and money
laundering; authorize checks; establish frequent shopper programs; automate
transaction settlement, card management and claims processing; and issue and
manage multi-functional applications on smart cards. Products in the ACI
Worldwide business unit represented approximately 76% of our revenue during our
2001 fiscal year.

     Insession Technologies. Products in this business unit facilitate
communication, data movement, monitoring of systems and business process
automation across computing systems involving mainframes, distributed computing
networks and the Internet and its primary products include ICE, Enguard,
WorkPoint and Extractor/Replicator. Insession Technologies products represented
approximately 14% of our revenue during our 2001 fiscal year.

     IntraNet, Inc. Products in this business unit include solutions for high
value payments processing, bulk/recurring payments processing, wire room
processing, global messaging, integrated payments management and Continuous Link
Settlement processing. The high value payments processing product is Money
Transfer System and is used by financial institutions to facilitate
business-to-business e-payments. The bulk and recurring payments processing
product is CoACH and is used by financial institutions to automatically deposit
paychecks and process other automated clearing house transactions. Products in
the IntraNet, Inc. business unit represented approximately 10% of our revenue
during our 2001 fiscal year.

                                       4


         WHERE YOU CAN FIND MORE INFORMATION; INCORPORATION BY REFERENCE

     We file annual, quarterly and special reports, proxy statements and other
information with the Securities and Exchange Commission (the "SEC"). You may
read and copy (upon the payment of fees prescribed by the SEC) any document that
we file with the SEC at its Public Reference Room at 450 Fifth Street, N.W.,
Washington, D.C. 20549. You may call the SEC at 1-800-SEC-0330 for further
information on the Public Reference Room. Our SEC filings are also available to
the public on the Internet, through the SEC's EDGAR database. You may access the
EDGAR database at the SEC's web site at http://www.sec.gov.

     The SEC allows us to "incorporate by reference" into this prospectus the
information we file with it. This means that we can disclose important business,
financial and other information in our filings by referring you to the documents
containing this information. All information incorporated by reference is part
of this prospectus, unless and until that information is updated and superseded
by the information contained in this prospectus or any information incorporated
later. Any information that we subsequently file with the SEC that is
incorporated by reference will automatically update and supersede any previous
information that is part of this prospectus. We incorporate into this prospectus
by reference the following documents and any subsequent filings we make with the
SEC under Sections 13(a), 13(c), 14, or 15(d) of the Securities Exchange Act of
1934:

   o  Annual Report on Form 10-K for the fiscal year ended September 30, 2001;

   o  Quarterly Report on Form 10-Q for the quarter ended December 31, 2001; and

   o  The description of our Class A Common Stock contained in our
      registration statement on Form 8-A that we filed with the SEC on
      January 11, 1995 under the Securities Exchange Act, including any
      amendment or reports that we file for the purposes of updating this
      description.

     This prospectus is part of a registration statement on Form S-3 that we
have filed with the SEC relating to the shares of our Class A Common Stock
offered by this prospectus. As permitted by SEC rules, this prospectus does not
contain all the information contained in that registration statement and its
accompanying exhibits and schedules, which we have also filed with the SEC. You
may refer to the registration statement, exhibits and schedules for more
information about us and our shares. The registration statement, exhibits and
schedules are available at the SEC's Public Reference Room or through its EDGAR
database on the Internet.

     You may obtain a copy of these filings, at no cost, by writing or
telephoning us at the following address:

                              David P. Stokes, Esq.
                          General Counsel and Secretary
                      Transaction Systems Architects, Inc.
                             224 South 108th Avenue
                              Omaha, Nebraska 68154
                                 (402) 334-5101

     To ensure timely delivery of these materials, you should submit any request
no later than five business days prior to the date on which you must make your
investment decision.

                                 USE OF PROCEEDS

     The shares of our Class A Common Stock will be sold by the holders of
preferred stock of TSA Exchangeco Limited. See "Plan of Distribution." We will
receive no proceeds in connection with such sales.

                        DESCRIPTION OF TSA CAPITAL STOCK

     Our Amended and Restated Certificate of Incorporation provides that our
authorized capital stock consists of 50,000,000 shares of Class A Common Stock,
par value $.005 per share, 5,000,000 shares of Class B Common Stock, par value
$.005 per share, and 5,450,000 shares of preferred stock, par value of $.01 per
share.

                                       5


Common Stock

     The holders of our Class A Common Stock and Class B Common Stock have the
same rights except that holders of Class B Common Stock are not entitled to vote
except as provided by law. Holders of Class A Common Stock are entitled to one
vote per share on all matters to be voted on by the stockholders. Subject to
preferences that may be applicable to any preferred stock outstanding at the
time, holders of common stock are entitled to receive ratably such dividends, if
any, as may be declared from time to time by the board of directors out of funds
legally available. In the event of a liquidation, dissolution or winding up of
TSA, holders of all common stock are entitled to share ratably in all assets
remaining after payment of our liabilities and the liquidation preference, if
any, of any outstanding preferred stock. Holders of common stock have no
preemptive rights and no rights to convert their Class A Common Stock into any
other securities, and there are no redemption provisions with respect to shares
of common stock. All of the outstanding shares of common stock are fully paid
and non-assessable. The rights, preferences and privileges of holders of common
stock are subject to, and may be adversely affected by, the rights of the
holders of shares of any series of preferred stock which we may designate and
issue.

Preferred Stock

     Our board of directors has the authority, without any further vote or
action by the stockholders, to provide for the issuance of up to 5,450,000
shares of preferred stock from time to time in one or more series with such
designations, rights, preferences and limitations as the board of directors may
determine, including the consideration received therefor, the number of shares
comprising each series, dividend rates, redemption provisions, liquidation
preferences, sinking fund provisions, conversion rights and voting rights, all
without approval by the holders of common stock. Although it is not possible to
state the effect that any issuance of preferred stock might have on the rights
of holders of common stock, the issuance of preferred stock may have one or more
of the following effects:

   o  restrict common stock dividends if preferred stock dividends have not been
      paid,

   o  dilute the voting power and equity interest of holders of common stock, or

   o  prevent current holders of common stock from participating in our assets
      upon liquidation until any liquidation preferences granted to holders of
      preferred stock are satisfied.

     In addition, the issuance of preferred stock may, under certain
circumstances, have the effect of discouraging a change in control of TSA by,
for example, granting voting rights to holders of preferred stock that require
approval by the separate vote of the holders of preferred stock for any
amendment to our Amended and Restated Certificate of Incorporation or any
reorganization, consolidation, merger (or other similar transaction involving
us). As a result, the issuance of such preferred stock may discourage bids for
our common stock at a premium over the market price therefor and could have a
material adverse effect on the market value of the common stock. Except for the
one share of Special Preferred Voting Stock described below, no shares of
preferred stock are currently outstanding.

Special Preferred Voting Stock

     Our board of directors has designated one share of preferred stock as
Special Preferred Voting Stock. The Special Preferred Voting Stock was issued in
connection with our acquisition of MessagingDirect Ltd. On all matters presented
to holders of our common stock, the Special Preferred Voting Stock is entitled
to the number of votes equal to the number of outstanding TSA Exchangeco
exchangeable shares not held by us or our affiliates. The Special Preferred
Voting Stock is held by a trustee for and on behalf of the holders of TSA
Exchangeco exchangeable shares. For each TSA Exchangeco exchangeable share held
on the record date, the holder is entitled to instruct the trustee as to the
manner of voting one vote. The Special Preferred Voting Stock and the Class A
Common Stock vote together as a single class. No dividend will be paid to the
holder of Special Preferred Voting Stock. The Special Preferred Voting Stock is
not convertible. The holder of the Special Preferred Voting Stock is not
entitled to participate in any payment or distribution upon any liquidation,
dissolution or winding up of TSA. The share of Special Preferred Voting Stock,
if purchased or otherwise acquired by us, will be canceled and may not be
reissued. When the TSA Exchangeco exchangeable shares are no longer outstanding,
the Special Preferred Voting Stock will automatically be cancelled.

                                       6


Delaware Law

     Under Section 203 of the Delaware General Corporation Law, certain
"business combinations" between a Delaware corporation whose stock generally is
publicly traded or held of record by more than 2,000 stockholders and an
"interested stockholder" are prohibited for a three-year period following the
date that such stockholder became an interested stockholder, unless:

   o  the corporation has elected in its original certificate of incorporation
      not to be governed by Section 203 (we did not make such an election),

   o  the business combination was approved by the board of directors of the
      corporation before the other party to the business combination became an
      interested stockholder,

   o  upon consummation of the transaction that made it an interested
      stockholder, the interested stockholder owned at least 85% of the voting
      stock of the corporation outstanding at the commencement of the
      transaction (excluding voting stock owned by directors who are also
      officers or held in employee benefit plans in which the employees do not
      have a confidential right to tender or vote stock held by the plan), or

   o  the business combination was approved by the board of directors of the
      corporation and ratified by two-thirds of the voting stock which the
      interested stockholder did not own.

     The three-year prohibition also does not apply to certain business
combinations proposed by an interested stockholder following the announcement or
notification of certain extraordinary transactions involving the corporation and
a person who had not been an interested stockholder during the previous three
years or who became an interested stockholder with the approval of the majority
of the corporation's directors. The term "business combination" is defined
generally to include mergers or consolidations between a Delaware corporation
and an "interested stockholder," transactions with an "interested stockholder"
involving the assets or stock of the corporation or its majority-owned
subsidiaries and transactions which increase an interested stockholder's
percentage ownership of stock. The term "interested stockholder" is defined
generally as a stockholder who, together with affiliates and associates, owns
(or, within three years prior, did own) 15% or more of a Delaware corporation's
voting stock. Section 203 could prohibit or delay a merger, takeover or other
change in control of TSA and therefore could discourage attempts to acquire us.

Transfer Agent and Registrar

     The transfer agent and registrar of our Class A Common Stock is Wells Fargo
Bank Minnesota, N.A.

                              SELLING STOCKHOLDERS

     We are registering shares of our Class A Common Stock to permit the selling
stockholders to offer such shares for resale. The selling stockholders acquired
the shares of Class A Common Stock in connection with the transactions described
below. A selling stockholder may offer all or some portion of shares of Class A
Common Stock. No estimate can be given as to the amount or percentage of Class A
Common Stock that will be held by the selling stockholders upon termination of
any particular offering. The aggregate holdings of the group of selling
stockholders is less than 1% of the shares of Class A Common Stock outstanding.

     On January 11, 2001, we and certain subsidiaries issued securities in
exchange for all of the outstanding securities of MessagingDirect Ltd., an
Alberta, Canada company. In connection with our acquisition of MessagingDirect
Ltd., our subsidiary, TSA Exchangeco Limited, issued 600,000 shares of
nonvoting, Canadian dollar denominated preferred stock, to another of our
subsidiaries, which in turn sold the preferred stock to ten of our management
level employees who are not executive officers. Each employee purchased 60,000
of the shares in a transaction exempt from registration pursuant to Section 4(2)
of the Securities Act. The securities were offered only to these ten employees,
the employees agreed to resale restrictions, and the certificates representing
the securities were marked to show applicable restrictions on transfer.

     The aggregate purchase price for the preferred shares was 1,490,000
Canadian dollars, which equated to

                                       7


1,000,000 U.S. dollars on the date of issuance. The preferred shares are
exchangeable by the holders for shares of our Class A Common Stock after two
years from the date of issuance of the preferred shares or earlier upon a change
of control of TSA. Subject to adjustments, the number of shares of Class A
Common Stock issuable upon exchange of a preferred share (the "Ratio") is equal
to the quotient of the purchase price of the preferred stock (plus any accrued
and unpaid dividends) and 115% of the Canadian dollar equivalent of the average
market price for our Class A Common Stock for the 20-day trading period ended
prior to the date of issuance of the preferred shares as determined in the
manner set out in the preferred share provisions. As of the date of issuance of
the preferred shares and subject to adjustments, the total number of shares of
Class A Common Stock that would be issuable upon exchange of all of the
preferred shares was 67,679.

     TSA Exchangeco Limited or certain of our other subsidiaries may elect to
redeem the preferred shares after two years from the date of their issuance, or
earlier upon a change of control of TSA or termination of employment of the
holder, for shares of Class A Common Stock with a market value (as determined
based on an average market price) at the time of redemption equal to the greater
of (i) the purchase price (plus any accrued and unpaid dividends) or (ii) the
fair market value of the preferred shares. If there is no agreement on the fair
market value, then it will be determined pursuant to the preferred share
provisions which provide, in general, that it will equal the number of shares of
Class A Common Stock determined pursuant to the Ratio plus the then present
value of any unpaid dividends payable with respect to periods after the early
redemption through the mandatory redemption date. If the preferred shares have
not been earlier exchanged or redeemed, then they are to be mandatorily redeemed
for cash equal to the purchase price plus any accrued but unpaid dividends on
the fifth anniversary date of their issuance. As of the date of issuance of the
preferred shares and subject to adjustments, the total number of shares of Class
A Common Stock that would be issuable upon redemption of all the preferred
shares was 67,679.

                              PLAN OF DISTRIBUTION

     The Class A Common Stock into which the preferred shares are convertible
are being registered to permit public secondary trading of these securities by
the selling stockholders from time to time after the date of this prospectus.
The selling stockholders may sell the Class A Common Stock directly to
purchasers or through underwriters, broker-dealers or agents. If shares of the
Class A Common Stock are sold through underwriters or broker-dealers, the
selling stockholder will be responsible for underwriting discounts or
commissions or agent's commissions. These discounts, concessions or commissions
as to any particular underwriter, broker-dealer or agent may be in excess of
those customary in the types of transactions involved. The Class A Common Stock
may be sold in one or more transactions at fixed prices, at prevailing market
prices at the time of sale, at varying prices determined at the time of sale, or
at negotiated prices. Sales may be effected in transactions, which may involve
block transactions or crosses:

   o  on any national securities exchange or quotation service on which the
      Class A Common Stock may be listed or quoted at the time of sale;

   o  in the over-the-counter market;

   o  in transactions otherwise than on exchanges or quotation services or in
      the over-the-counter market; or

   o  through the writing of options.

     The aggregate proceeds to the selling stockholders from the sale of the
Class A Common Stock offered by them pursuant to this prospectus will be the
purchase price of the Class A Common Stock less discounts and commissions, if
any. Each of the selling stockholders reserves the right to accept and, together
with their agents from time to time, to reject, in whole or in part, any
proposed purchase of Class A Common Stock to be made directly or through agents.
We will not receive any of the proceeds from this offering.

     In order to comply with the securities laws of some states, if applicable,
the Class A Common Stock may be sold in these jurisdictions only through
registered or licensed brokers or dealers. In addition, in some states the Class
A Common Stock may not be sold unless they have been registered or qualified for
sale or an exemption from registration or qualification requirements is
available and is complied with.

                                       8


     The selling stockholders and any underwriters, broker-dealers or agents
that participate in the sale of the Class A Common Stock may be "underwriters"
within the meaning of Section 2(11) of the Securities Act. Any discounts,
commissions, concessions or profit they earn on any resale of the shares may be
underwriting discounts and commissions under the Securities Act. Selling
stockholders who are "underwriters" within the meaning of Section 2(11) of the
Securities Act will be subject to the prospectus delivery requirements of the
Securities Act. They may also be subject to certain statutory liabilities,
including, but not limited to, those of Sections 11, 12 and 17 of the Securities
Act and Rule 10b-5 under the Exchange Act.

     We are not aware of any plans, arrangements or understandings between any
selling stockholders and any underwriter, broker-dealer or agent regarding the
sale of the common stock by the selling stockholders. The selling stockholders
have acknowledged that they understand their obligations to comply with the
provisions of the Exchange Act and the rules thereunder relating to stock
manipulation, particularly Regulation M.

     We agreed to register the Class A Common Stock under applicable federal and
state securities laws for the benefit of the selling stockholders. We have
agreed, among other things, to bear all expenses (other than underwriting
discounts and selling commissions) in connection with the registration and sale
of the Class A Common Stock covered by this prospectus.

                                  LEGAL MATTERS

     The validity of the Class A Common Stock offered pursuant to this
prospectus will be passed upon for us by Baker & McKenzie, Dallas, Texas.

                                     EXPERTS

     The financial statements incorporated by reference in this prospectus,
which are included in our Annual Report on Form 10-K for the fiscal year ended
September 30, 2001, have been audited by Arthur Andersen LLP, independent public
accountants, as indicated in their report with respect thereto, and are included
herein in reliance upon the authority of said firm as experts in giving said
report.

     Our future financial statements and the reports thereon of our independent
public accountants also will be incorporated by reference in this prospectus in
reliance upon the authority of those independent public accountants as experts
in giving those reports to the extent said firm has audited those financial
statements and consented to the use of their reports thereon.

                                       9


                                    PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

Item 14. Other Expenses of Issuance and Distribution

     The following table sets forth the costs and expenses payable by the
registrant in connection with the sale of the securities being registered
hereby. All amounts are estimates except the registration fee.

              Legal fees and expenses                    $12,000
              Accounting fees and expenses                 2,500
              Registration fee                               100
              Miscellaneous                                  500
                                                         -------
              Total                                      $15,100
                                                         -------

Item 15. Indemnification of Directors and Officers

     Section 145 of the General Corporation Law of the State of Delaware permits
indemnification by a corporation of certain officers, directors, employees and
agents. Consistent therewith, Article Tenth of the Amended and Restated
Certificate of Incorporation of Transaction Systems Architects, Inc. ("TSA")
provides that TSA, to the fullest extent authorized by the General Corporation
Law of the State of Delaware, as the same exists or may hereafter be amended
(but, in the case of any such amendment, only to the extent that such amendment
permits TSA to provide broader indemnification rights than such law permitted
TSA to provide prior to such amendment), to indemnify a director or officer of
TSA or a person who is or was serving at the request of TSA as director,
officer, employee or agent of another corporation or of a partnership, joint
venture, trust or other enterprise, including service with respect to an
employee benefit plan, who was or is made (or threatened to be made) a party to
a civil, criminal, administrative or investigative proceeding (an "indemnified
person"). Article Tenth also provides that expenses incurred by an indemnified
person will be paid in advance by TSA; provided, however, that, if the General
Corporation Law of the State of Delaware requires, an advancement of expenses
incurred by an indemnified person incurred in his or her capacity as a director
or officer will be made only if TSA receives an undertaking by or on behalf of
the indemnified person to repay all amounts so advanced if it shall ultimately
be determined by final judicial decision from which there is no further right to
appeal that such indemnified person is not entitled to be indemnified for such
expenses. The Amended and Restated Certificate of Incorporation also authorizes
TSA to maintain officer and director liability insurance, and such a policy is
currently in effect.

     TSA entered into Severance Compensation Agreements with each of its
executive officers and certain other employees. Under the Agreements, TSA agrees
to indemnify the employee to the fullest extent permitted by law if the employee
is a party or threatened to be made a party to any action, suit or proceeding in
which the employee is involved by reason of the fact that the employee is or was
a director or officer of TSA, by reason of any action taken by him or of any
action on his part while acting as director or officer of TSA, or by reason of
the fact that he is or was serving at the request of TSA as a director, officer,
employee or agent of another enterprise. TSA also agrees to obtain and maintain
a directors' and officers' liability insurance policy covering the employee.

     Under a registration rights agreement between TSA and certain of its
stockholders, TSA agreed to indemnify each stockholder selling his or her shares
thereunder in connection with any losses, claims, damages or liabilities arising
out of certain acts or omissions of TSA. Under an agreement with the purchasers
of TSA's Senior Convertible Preferred Stock and warrants, TSA indemnified the
purchasers with respect to any misrepresentation or breach of any representation
or warranty or noncompliance with any conditions or other agreements given or
made in connection with the agreement or the transactions contemplated therein.

                                      II-1


Item 16. Exhibits

  Exhibit
  Number     Description

   3.01(1)   Amended and Restated Certificate of Incorporation of TSA, and
             amendments thereto
   3.02(2)   Amended and Restated Bylaws of TSA, and First Amendment thereto
   4.01(1)   Form of Common Stock Certificate
   5.01      Opinion of Baker & McKenzie
  23.01      Consent of Arthur Andersen LLP
  23.02      Consent of Baker & McKenzie (included in opinion filed as Exhibit
             5.01)
  24.01      Power of Attorney (included on the signature page of this
             Registration Statement)
--------------
  (1) Incorporated by reference to the exhibit of the same number to the
      Registrant's Registration Statement No. 33-88292 on Form S-1.
  (2) Incorporated by reference to the exhibit of the same number to the
      Registrant's Annual Report on Form 10-K for the fiscal year ended
      September 30, 1999.

Item 22. Undertakings

     (a) The undersigned registrant hereby undertakes:

         (1) to file, during any period in which offers or sales are being made,
a post-effective amendment to this registration statement:

                (i) to include any prospectus required by Section 10(a)(3) of
the Securities Act of 1933;

               (ii) to reflect in the prospectus any facts or events arising
after the effective date of the registration statement (or the most recent
post-effective amendment thereof) which, individually or in the aggregate,
represent a fundamental change in the information set forth in the registration
statement. Notwithstanding the foregoing, any increase or decrease in volume of
securities offered (if the total dollar value of securities offered would not
exceed that which was registered) and any deviation from the low or high end of
the estimated maximum offering range may be reflected in the form of prospectus
filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in
volume and price represent no more than a 20% change in the maximum aggregate
offering price set forth in the "Calculation of Registration Fee" table in the
effective registration statement; and

              (iii) to include any material information with respect to the plan
of distribution not previously disclosed in the registration statement or any
material change to such information in the registration statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the
information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed with or furnished to the SEC
by the registrant pursuant to section 13 or section 15(d) of the Securities
Exchange Act of 1934 that are incorporated by reference in the registration
statement;

         (2) that, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof; and

         (3) to remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

     (b) The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Securities Exchange Act of 1934 (and, where applicable, each filing of an
employee benefit plan's annual report pursuant to Section 15(d) of the
Securities Exchange Act of 1934) that is incorporated by reference in the
registration statement shall be deemed to be a new registration statement
relating to the securities offered therein,

                                      II-2


and the offering of such securities at that time shall be deemed to be the
initial bona fide offering thereof.

     (c) Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
registrant pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the registrant of expenses incurred
or paid by a director, officer or controlling person of the registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.

                                      II-3



                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized in the City of Omaha, State of Nebraska, on April 10, 2002.

                                     TRANSACTION SYSTEMS ARCHITECTS, INC.


                                     By: /s/ DWIGHT G. HANSON
                                         --------------------------------------
                                         Dwight G. Hanson
                                         Chief Financial Officer, Treasurer and
                                         Senior Vice President


                                POWER OF ATTORNEY

     Each person whose signature appears below hereby constitutes and appoints
Dwight G. Hanson his true and lawful attorney-in-fact and agent, with full power
of substitution and resubstitution for him and his name, place and stead, in any
and all capacities, to sign any and all amendments to this Registration
Statement on Form S-3, including any post-effective amendments, and any
additional Registration Statement filed pursuant to Rule 462(b) under the
Securities Act of 1933, and all instruments necessary or advisable in connection
therewith, with the Securities and Exchange Commission, said attorney and agent
to have power to act and to have full power and authority to do and perform in
the name and on behalf of each of the undersigned every act whatsoever necessary
or advisable to be done in the premises as fully and to all intents and purposes
as any of the undersigned might or could do in person, and each of the
undersigned hereby ratifies and confirms his signature as it may be signed by
said attorney and agent to any and all such amendment and amendments.

     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the dates indicated.


             Name                            Title                     Date


 /s/ GREGORY D. DERKACHT         President, Chief Executive       April 10, 2002
------------------------------   Officer and Director
Gregory D. Derkacht

 /s/ DWIGHT G. HANSON            Chief Financial Officer,         April 10, 2002
------------------------------   Treasurer and Senior Vice
Dwight G. Hanson                 President

 /s/ EDWARD C. FUXA              Chief Accounting Officer,        April 10, 2002
-----------------------------    Vice President and Controller
Edward C. Fuxa

 /s/ GREGORY J. DUMAN            Chairman of the Board            April 10, 2002
------------------------------   and Director
Gregory J. Duman

 /s/ LARRY G. FENDLEY            Director                         April 10, 2002
------------------------------
Larry G. Fendley

 /s/ JIM D. KEVER                Director                         April 10, 2002
------------------------------
Jim D. Kever

 /s/ ROGER K. ALEXANDER          Director                         April 10, 2002
------------------------------
Roger K. Alexander






                                  EXHIBIT INDEX

  Exhibit
  Number     Description

   3.01(1)   Amended and Restated Certificate of Incorporation of TSA, and
             amendments thereto
   3.02(2)   Amended and Restated Bylaws of TSA, and First Amendment thereto
   4.01(1)   Form of Common Stock Certificate
   5.01      Opinion of Baker & McKenzie
  23.01      Consent of Arthur Andersen LLP
  23.02      Consent of Baker & McKenzie (included in opinion filed as Exhibit
             5.01)
  24.01      Power of Attorney (included on the signature page of this
             Registration Statement)
--------------
  (1) Incorporated by reference to the exhibit of the same number to the
      Registrant's Registration Statement No. 33-88292 on Form S-1.
  (2) Incorporated by reference to the exhibit of the same number to the
      Registrant's Annual Report on Form 10-K for the fiscal year ended
      September 30, 1999.