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

                                 SCHEDULE 13D

      INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULE 13d-1(a) 
                AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2(a)

                               (Amendment No. 9)1

                               Acxiom Corporation
                ------------------------------------------------
                                (Name of Issuer)

                     Common Stock, Par Value $0.10 per share
                ------------------------------------------------
                         (Title of Class of Securities)

                                  005125109
                ------------------------------------------------
                                (CUSIP Number)

                             Allison Bennington
                              ValueAct Capital
                        435 Pacific Avenue, Fourth Floor
                           San Francisco, CA 94133
                              (415) 362-3700
                ------------------------------------------------
               (Name, Address and Telephone Number of Person
              Authorized to Receive Notices and Communications)

                               With a Copy to:
                        Christopher G. Karras, Esq.
                               Dechert LLP
                          4000 Bell Atlantic Tower
                            1717 Arch Street
                     Philadelphia, Pennsylvania 19103-2793
                          Ph. (215) 994-4000

                             October 18, 2005
                ------------------------------------------------
           (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to
report the acquisition that is the subject of this Schedule 13D, and is
filing this schedule because of Rule 240.13d-1(b)(e), 240.13d-1(f) or
240.13d-1(g) check the following box [ ].

NOTE: Schedules filed in paper format shall include a signed original and
five copies of the schedule, including all exhibits.  See Rule 240.13d-7(b)
for other parties to whom copies are to be sent

1The remainder of this cover page shall be filled out for a reporting
person's initial filing on this form with respect to the subject class of
securities, and for any subsequent amendment containing information which
would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be
deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section
of the Act but shall be subject to all other provisions of the Act (however,
see the Notes).
=============================================================================


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 005125109                                              Page 2 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   ValueAct Capital Master Fund, L.P.
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   WC*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   British Virgin Islands
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         10,184,895**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        10,184,895**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
    10,184,895**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

   11.6%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    PN
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
             INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
               (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE
                                ATTESTATION.

                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 005125109                                              Page 3 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   ValueAct Capital Partners Co-Investors, L.P.
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   WC*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   Delaware
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         138,660**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        138,660**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
    138,660**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    Less than 1%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    PN
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
             INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
               (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE
                                ATTESTATION.

                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 005125109                                              Page 4 of 13
----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   VA Partners, L.L.C. 
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   WC*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   Delaware
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         10,323,555**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        10,323,555**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
    10,323,555**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    11.7%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    00 (LLC)
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
             INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
               (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE
                                ATTESTATION.


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 005125109                                             Page 5 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   Jeffrey W. Ubben 
---------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

---------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
----------------------------------------------------------------------------- 
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                         [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   United States
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         10,323,555**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        10,323,555**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
    10,323,555**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    11.7%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    IN
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
             INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
               (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE
                                ATTESTATION.


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 005125109                                              Page 6 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   George F. Hamel, Jr. 
---------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
-----------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                        [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   United States
-----------------------------------------------------------------------------
                   7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES          8.  SHARED VOTING POWER
   BENEFICIALLY         10,323,555**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH     9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        10,323,555**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
    10,323,555**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    11.7%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    IN
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
             INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
               (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE
                                ATTESTATION.


                                SCHEDULE 13D
--------------------------                          -------------------------
CUSIP NO. 005125109                                             Page 7 of 13
-----------------------------------------------------------------------------
1. NAME OF REPORTING PERSON/S.S. OR I.R.S. INDENTIFICATION NO. OF ABOVE
   PERSON (entities only)

   Peter H. Kamin 
-----------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*                  (a) [X]
                                                                      (b) [ ]
---------------------------------------------------------------------------
3. SEC USE ONLY

-----------------------------------------------------------------------------
4. SOURCE OF FUNDS*

   00*
-----------------------------------------------------------------------------
5. CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
   PURSUANT TO ITEMS 2(d) or 2(e)                                        [ ]
-----------------------------------------------------------------------------
6. CITIZENSHIP OR PLACE OF ORGANIZATION

   United States
-----------------------------------------------------------------------------
                    7.  SOLE VOTING POWER
                        0
   NUMBER OF       ----------------------------------------------------------
   SHARES           8.  SHARED VOTING POWER
   BENEFICIALLY         10,323,555**
   OWNED BY EACH   ----------------------------------------------------------
   PERSON WITH      9.  SOLE DISPOSITIVE POWER
                        0
                   ----------------------------------------------------------
                   10.  SHARED DISPOSITIVE POWER
                        10,323,555**
-----------------------------------------------------------------------------
11. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
 
    10,323,555**
-----------------------------------------------------------------------------
12. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
    CERTAIN SHARES                                                        [ ]
-----------------------------------------------------------------------------
13. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

    11.7%
-----------------------------------------------------------------------------
14. TYPE OF REPORTING PERSON

    IN
-----------------------------------------------------------------------------
*See Item 3
**See Item 2 and 5
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!
             INCLUDE BOTH SIDES OF THE COVER PAGE, RESPONSES TO ITEMS 1-7
               (INCLUDING EXHIBITS) OF THE SCHEDULE, AND THE SIGNATURE
                                ATTESTATION.



THE PURPOSE OF THIS AMENDMENT NO. 9 TO SCHEDULE 13D IS TO AMEND THE OWNERSHIP
REPORTS OF THE REPORTING PERSONS.  THE INFORMATION BELOW SUPPLEMENTS THE
INFORMATION PREVIOUSLY PROVIDED.

ITEM 1.  SECURITY AND ISSUER.

         This Schedule 13D relates to the common stock, $0.10 par
value per share (the "Common Stock"), of Acxiom Corporation, a Delaware
corporation (the "Issuer").  The address of the principal executive
offices of the Issuer is P.O. Box 8180, 1 Information Way, Little Rock,
Arkansas 72203.

ITEM 2.  IDENTITY AND BACKGROUND.

         This statement is filed jointly by (a) ValueAct Capital Master Fund,
L.P. ("ValueAct Master Fund"), (b) ValueAct Capital Partners Co-
Investors, L.P. ("ValueAct Co-Investors"), (c) VA Partners, L.L.C. ("VA
Partners"), (d) Jeffrey W. Ubben, (e) George F. Hamel, Jr. and (f) Peter
H. Kamin (collectively, the "Reporting Persons").

ValueAct Co-Investors is a Delaware limited partnership. ValueAct Master
Fund is a limited partnership organized under the laws of the British
Virgin Islands. Each has a principal business address of 435 Pacific
Avenue, Fourth Floor, San Francisco, CA 94133.

VA Partners is a Delaware limited liability company, the principal
business of which is to serve as the General Partner to ValueAct Master
Fund and ValueAct Co-Investors. VA Partners has a principal business
address of 435 Pacific Avenue, Fourth Floor, San Francisco, CA 94133. 

(a), (b) and (c). Messrs. Ubben, Hamel and Kamin are each managing
members, principal owners and controlling persons of VA Partners, and
directors and such activities constitute their principal occupations.
Such individuals are sometimes collectively referred to herein as the
"Managing Members" or individually as a "Managing Member". Each 
Managing Member is a United States citizen and has a principal business
address of 435 Pacific Avenue, Fourth Floor, San Francisco, CA 94133.

 (d) and (e). None of the entities or persons identified in this Item 2
has during the past five years been convicted of any criminal proceeding
(excluding traffic violations or similar misdemeanors), nor been a party
to a civil proceeding of a judicial or administrative body of competent
judgment, decree or final order enjoining future violations of, or
prohibiting or mandating activities subject to, federal or state
securities laws or finding any violation with respect to such laws.

                               Page 8 of 13



ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

         The source of funds used for the purchase of the Issuer's
securities was the working capital of ValueAct Master Fund. The aggregate
funds used by these Reporting Persons to make the purchases was
$7,205,673.50.

ITEM 4.  PURPOSE OF TRANSACTION.

         The Reporting Persons have acquired the Issuer's Common Stock
for investment purposes, and such purchases have been made in the
Reporting Persons' ordinary course of business. 

         In pursuing such investment purposes, the Reporting Persons may
further purchase, hold, vote, trade, dispose or otherwise deal in the
Common Stock at times, and in such manner, as they deem advisable to
benefit from changes in market prices of such Common Stock, changes in
the Issuer's operations, business strategy or prospects, or from sale or
merger of the Issuer.  To evaluate such alternatives, the Reporting
Persons will routinely monitor the Issuer's operations, prospects,
business development, management, competitive and strategic matters,
capital structure, and prevailing market conditions, as well as
alternative investment opportunities, liquidity requirements of the
Reporting Persons and other investment considerations.  Consistent with
its investment research methods and evaluation criteria, the
Reporting Persons may discuss such matters with management or directors
of the Issuer, other shareholders, industry analysts, existing or 
potential strategic partners or competitors, investment and financing
professionals, sources of credit and other investors.  Such factors and
discussions may materially affect, and result in, the Reporting Persons'
modifying their ownership of Common Stock, exchanging information with
the Issuer pursuant to appropriate confidentiality or similar agreements,
proposing changes in the Issuer's operations, governance or
capitalization, or in proposing one or more of the other actions
described in subsections (a) through (j) of Item 4 of Schedule 13D. 

         The Reporting Persons reserve the right to formulate other plans
and/or make other proposals, and take such actions with respect to their
investment in the Issuer, including any or all of the actions set forth
in paragraphs (a) through (j) of Item 4 of Schedule 13D, or acquire
additional Common Stock or dispose of all the Common Stock beneficially
owned by them, in public market or privately negotiated transactions. 
The Reporting Persons may at any time reconsider and change their plans
or proposals relating to the foregoing.

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER

(a) and (b). Set forth below is the beneficial ownership of
shares of Common Stock of the Issuer for each person named in Item 2. 

Shares reported as beneficially owned by ValueAct Master Fund and
ValueAct Co-Investors are also reported as beneficially owned by VA
Partners, as investment manager or General Partner of each such
investment partnership, and by the Managing Members as controlling
persons of the General Partner. VA Partners and the Managing Members 


                               Page 9 of 13



also, directly or indirectly, may own interests in one or both of such
partnerships from time to time. Unless otherwise indicated below, by
reason of such relationships each of the partnerships is reported as
having shared power to vote or to direct the vote, and shared power to
dispose or direct the disposition of, such shares of Common Stock with VA
Partners and the Managing Members.

As of the date hereof, ValueAct Master Fund is the beneficial owner
of 10,184,895 shares of Common Stock, representing approximately 11.6% of
the Issuers outstanding Common Stock. ValueAct Co-Investors is the
beneficial owner of 138,660 shares of Common Stock representing less than
1% of the Issuers outstanding Common Stock.

VA Partners and each of the Managing Members may be deemed the beneficial
owner of an aggregate of 10,323,555 shares of Issuer Common stock,
representing approximately 11.7% of the Issuers outstanding Common Stock.
All percentages set forth in this Schedule 13D are based upon the
Issuer's reported 87,883,601 outstanding shares of Common Stock as
reported in the Issuer's Form 10-Q for the period ended June 30,
2005.

(c) During the sixty (60) days preceding the date of this report, the
Reporting Persons purchased the following shares of Common Stock in
the open market.

 
Reporting Person          Trade Date     Shares    Price/Share
----------   	        ---------      -------   -----------

ValueAct Master Fund      10-18-05       100,000     $18.82
                          10-18-05       100,000     $18.89
                          10-18-05        50,000     $18.67
                          10-19-05        25,225     $18.84
                          10-19-05       106,700     $18.85
                          
                       
(d) and (e) Not applicable.
                      


                               Page 10 of 13






ITEM 6.  CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH
RESPECT TO SECURITIES OF THE ISSUER

Other than previously disclosed, the Reporting Persons have no
understandings, arrangements, relationships or contracts relating to the
Common Stock which are required to be described hereunder.   

ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS

A. Joint Filing Agreement







                               Page 11 of 13




                                  SIGNATURES

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete
and correct.

                             POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below on this Schedule 13D hereby constitutes and appoints Jeffrey W. Ubben,
George F. Hamel, Jr. and Peter H. Kamin, and each of them, with full power to
act without the other, his true and lawful attorney-in-fact and agent, with
full power of substitution and resubstitution, for him and in his name, place
and stead, in any and all capacities (until revoked in writing) to sign any
and all amendments to this Schedule 13D, and to file the same, with all
exhibits thereto and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and
agents, and each of them, full power and authority to do and perform each and
every act and thing requisite and necessary fully to all intents and purposes
as he might or could do in person, thereby ratifying and confirming all that
said attorneys-in-fact and agents or any of them, or their or his substitute
or substitutes, may lawfully do or cause to be done by virtue hereof.

                              ValueAct Capital Master Fund L.P., by 
                              VA Partners, L.L.C., its General Partner

                              By:     /s/  George F. Hamel, Jr.  
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member

                              ValueAct Capital Partners Co-Investors L.P.,
                              by VA Partners, L.L.C., its General Partner

                              By:     /s/  George F. Hamel, Jr.  
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member

                              VA Partners, L.L.C.

                              By:    /s/  George F. Hamel, Jr.    
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member


                              By:    /s/  Jeffrey W. Ubben
                                --------------------------------------
Dated:  October 27, 2005        Jeffrey W. Ubben, Managing Member


                              By:    /s/  George F. Hamel, Jr.    
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member


                              By:    /s/  Peter H. Kamin
                                --------------------------------------
Dated:  October 27, 2005        Peter H. Kamin, Managing Member

                               Page 12 of 13




                                   Exhibit A
                           JOINT FILING UNDERTAKING

The undersigned parties hereby agree that the Schedule 13D filed herewith
(and any amendments thereto) relating to the Common Stock of Acxiom
Corporation is being filed jointly on behalf of each of them with the
Securities and Exchange Commission pursuant to Section 13(d) of the
Securities Exchange Act of 1934, as amended.


                              ValueAct Capital Master Fund L.P., by 
                              VA Partners, L.L.C., its General Partner


                              By:     /s/  George F. Hamel, Jr.  
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member

                              ValueAct Capital Partners Co-Investors L.P., by 
                              VA Partners, L.L.C., its General Partner


                              By:     /s/  George F. Hamel, Jr.  
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member


                              VA Partners, L.L.C.

                              By:    /s/  George F. Hamel, Jr.    
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member


                              By:    /s/  Jeffrey W. Ubben
                                --------------------------------------
Dated:  October 27, 2005        Jeffrey W. Ubben, Managing Member


                              By:    /s/  George F. Hamel, Jr.    
                                --------------------------------------
Dated:  October 27, 2005        George F. Hamel, Jr., Managing Member


                              By:    /s/  Peter H. Kamin
                                --------------------------------------
Dated:  October 27, 2005        Peter H. Kamin, Managing Member



                               Page 13 of 13