EXHIBIT 10.04A
                                                                                
                                        
       SECOND AMENDMENT OF EMPLOYEE PERFORMANCE STOCK PURCHASE AGREEMENT
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        This Second Amendment of Employee Performance Stock Purchase Agreement
is made effective as of March 18, 1998, by and between CSG SYSTEMS
INTERNATIONAL, INC., a Delaware corporation formerly known as CSG Holdings, Inc.
(the "Company"), and GEORGE HADDIX (the "Employee").


                                    *  *  *


        WHEREAS, the Company and the Employee are parties to that certain
Employee Performance Stock Purchase Agreement dated August 17, 1995, as amended
by a First Amendment thereto dated as of October 19, 1995 (the "Performance
Agreement"); and

        WHEREAS, the Company and the Employee desire to amend the Performance
Agreement as more particularly set forth below;

        NOW, THEREFORE, the Company and the Employee agree as follows:

        1.  Notwithstanding the provisions of Section 6(g) of the Performance
Agreement, the Company agrees that, at any time after the date of this Second
Amendment, the Employee may transfer the Unreleased Shares (as defined in the
Performance Agreement) to a limited partnership of which the Employee is a
general partner upon the conditions (i) that any Unreleased Shares so
transferred shall remain subject to the Repurchase Option under Section 3 of the
Performance Agreement until such Shares are released from the Repurchase Option
pursuant to Section 4 of the Performance Agreement, (ii) that such partnership
shall make no disposition of all or any portion of the Unreleased Shares
transferred to it by the Employee except in compliance with Section 6(g) of the
Performance Agreement (except that the provisions of Section 5 of the
Performance Agreement shall not be applicable), (iii) that the certificates for
any of the Unreleased Shares transferred to such partnership by the Employee
(the "Certificates") shall contain the following legends:

               THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
     REGISTERED UNDER THE SECURITIES ACT OF 1933 (THE "ACT") AND MAY NOT BE
     OFFERED, SOLD, OR OTHERWISE TRANSFERRED UNLESS AND UNTIL REGISTERED UNDER
     THE ACT OR, IN THE OPINION OF COUNSEL IN FORM AND SUBSTANCE SATISFACTORY TO
     THE ISSUER OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE, SUCH OFFER,
     SALE, OR TRANSFER IS IN COMPLIANCE WITH THE ACT.

               THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO A RIGHT
     OF REPURCHASE AND RESTRICTIONS ON TRANSFER, AS SET FORTH IN THE EMPLOYEE
     PERFORMANCE STOCK PURCHASE AGREEMENT DATED AUGUST 17, 1995, BETWEEN THE
     ISSUER AND GEORGE HADDIX, AS AMENDED, A COPY OF WHICH MAY BE OBTAINED AT
     THE PRINCIPAL OFFICE OF THE ISSUER.  SUCH RIGHT OF REPURCHASE AND
     RESTRICTIONS ON TRANSFER ARE BINDING ON TRANSFEREES OF THE SHARES
     REPRESENTED BY 

 
     THIS CERTIFICATE.;


(iv) that the Certificates shall remain subject to Joint Escrow Instructions
between the Company and such partnership substantially similar to those dated
August 17, 1995, between the Company and the Employee, (v) that the provisions
of Sections 6(f), 6(g), 10(b), 10(c), 11,12,13,14,15, and 16 of the Performance
Agreement shall continue to be applicable to the Company and such partnership,
and (vi) that such partnership shall execute and deliver to the Company such
document as the Company reasonably may request to evidence the agreement of such
partnership with the foregoing provisions of this Paragraph 1.  No transfer of
the Unreleased Shares shall be permitted by the Company pursuant to this
Paragraph 1 until the condition set forth in the preceding clause (vi) has been
satisfied.

     2. As hereby amended, the Performance Agreement shall remain in full force
and effect in accordance with its terms.

     IN WITNESS WHEREOF, the parties have executed this Second Amendment of
Employee Performance Stock Purchase Agreement as of the date first set forth
above.


                              CSG SYSTEMS INTERNATIONAL, INC., a Delaware
                              corporation formerly known as CSG Holdings, Inc.

                              By: /s/ Neal C. Hansen
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                                  Neal C. Hansen, Chairman of the Board and
                                  Chief Executive Officer



                                  /s/ George F. Haddix
                                  ----------------------------------------------
                                  George Haddix