8-K

================================================================================


                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


                                    FORM 8-K

                                 CURRENT REPORT


     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934


                        Date of Report: February 15, 2005
                        (Date of earliest event reported)

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


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


          Delaware                   0-25346                     47-0772104
(State or other jurisdiction       (Commission                (I.R.S. Employer
      of incorporation)            File Number)              Identification No.)


                             224 South 108th Avenue,
                              Omaha, Nebraska 68154
          (Address of principal executive offices, including zip code)


                                 (402) 334-5101
              (Registrant's telephone number, including area code)

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


Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

  [ ] Written communications pursuant to Rule 425 under the Securities Act
       (17 CFR 230.425)

  [ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act
       (17 CFR 240.14a-12)

  [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the
       Exchange Act (17 CFR 240.14d-2(b))

  [ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the
       Exchange Act (17 CFR 240.13e-4(c))


================================================================================






 Item 7.01.  Regulation FD Disclosure.

     On February 15, 2005, Transaction Systems Architects, Inc. issued a press
release responding to a public statement issued by JANA Partners LLC on February
14, 2005. A copy of this press release is attached hereto as Exhibit 99.1.

Item 9.01.  Financial Statements and Exhibits.

     Exhibit 99.1 -- Press Release dated February 15, 2005.












                                    SIGNATURE

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.


                                          TRANSACTION SYSTEMS ARCHITECTS, INC.


 Date: February 15, 2005                  By:        /s/ Dennis P. Byrnes
                                             -----------------------------------
                                                       Dennis P. Byrnes
                                                    Senior Vice President,
                                                General Counsel and Secretary








                                  EXHIBIT INDEX

       Exhibit
       Number     Description
       -------    -----------
         99.1     Press Release dated February 15, 2005.

EX-99

                                                                    Exhibit 99.1

                                                                    News Release

TRANSACTION SYSTEMS ARCHITECTS INC
224 SOUTH 108 AVENUE
OMAHA, NEBRASKA 68154
402.334.5101
FAX 402.390.8077


For more information contact:
William J. Hoelting
Vice President, Investor Relations
402.390.8990

FOR IMMEDIATE RELEASE

          TRANSACTION SYSTEMS ARCHITECTS RESPONDS TO JANA PARTNERS LLC

(Omaha, Neb. -- February 15, 2005) -- Responding to a public statement issued by
JANA Partners LLC on February 14, 2005, Gregory D. Derkacht, President and Chief
Executive Officer of Transaction Systems Architects, Inc. (Nasdaq:TSAI), said:
"TSA is not for sale. Our board of directors and management are focused on
executing our strategic plan, which we believe is in the long-term best interest
of the Company and all of our stockholders."

TSA is in the process of executing its strategy of building a premier electronic
payments software company. In the course of executing that strategy, management
has improved the Company's financial results from an operating loss of $56.1
million, or $(2.35) per diluted share, for fiscal 2001, to operating income of
$54.8 million, or earnings per diluted share of $1.23, which included a net
one-time tax benefit of $.28, for fiscal 2004. Over the same period, the
Company's stock price improved from $6.28 per share at the end of fiscal 2001 to
$18.59 per share at the end of fiscal 2004, a compound annual growth rate of
over 43 percent.

"Our board, with input from our financial advisors, remains focused on
enhancing our capital structure," said Mr. Derkacht. As previously announced,
TSA's board of directors has approved a stock repurchase program authorizing it
to acquire up to $80 million of its Class A Common Stock. Purchases will be made
from time to time as market and business conditions warrant, in open market,
negotiated or block transactions, in accordance with applicable laws, rules and
regulations. TSA has approximately 38.2 million shares of Class A Common Stock
outstanding. "Given TSA's strong balance sheet and cash flow, the stock
repurchase program represents an excellent use of capital and reflects our
commitment to enhancing stockholder value," Mr. Derkacht continued.

In its letter, JANA stated that they "know of at least two credible strategic
buyers that have expressed interest in buying the Company at a meaningful
premium to the current stock price" and that "these potential partners have been
discouraged and rebuffed by the TSAI board." Such statements are patently false
and misleading. TSA has not received any such credible expressions of interest
regarding a sale or change of control of the Company. While TSA is not for sale,
the Company's board of directors, consistent with its fiduciary duties, will
carefully consider any credible expressions of interest regarding a sale or
change of control of the Company if and when any such expressions of interest
are received.


About Transaction Systems Architects, Inc.

The Company's software facilitates electronic payments by providing consumers
and companies access to their money. Its products are used to process
transactions involving credit cards, debit cards, secure electronic commerce,
mobile commerce, smart cards, secure electronic document delivery and payment,
checks, high-value money transfers, bulk payment clearing and settlement, and
enterprise e-infrastructure. The Company's solutions are used on more than 1,740
product systems in 78 countries on six continents.


Forward-Looking Statements

Statements included in this press release may contain forward-looking
statements. Such forward-looking statements are made pursuant to the safe-harbor
provisions of the Private Securities Litigation Reform Act of 1995. The
forward-looking statements in this press release are subject to a variety of
risks and uncertainties. Actual results could differ materially.

For a detailed discussion of these and other risk factors, interested parties
should review the Company's filings with the Securities and Exchange Commission,
including the Company's Form 10-K filed on December 14, 2004 and the Form 10-Q
filed on February 8, 2005.