<PAGE>
                                                                    EXHIBIT 4(g)


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

                            CERTIFICATE OF AMENDMENT

                                       OF

                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                            COMPASS BANCSHARES, INC.

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

              (Originally incorporated under the name "Central and
                    State National Corporation of Alabama" on
                                December 8, 1970)


         Compass Bancshares, Inc., a corporation organized and existing under
and by virtue of the General Corporation Law of the State of Delaware, DOES
HEREBY CERTIFY:

         FIRST: That at a meeting of the Board of Directors of Compass
Bancshares, Inc., a resolution was duly adopted setting forth the proposed
amendment to the Restated Certificate of Incorporation of said corporation,
declaring such amendment to be advisable and calling for the presentation of the
proposed amendment to the stockholders of the corporation at the next annual
meeting. The resolution setting forth the proposed amendment is as follows:

         RESOLVED, that Article 4.1 of the corporation's Restated Certificate of
         Incorporation be revised to read as follows:

                           "4.1 Authorized Stock. The total number of shares of
                  all classes of stock which the Corporation shall have the
                  authority to issue is three hundred twenty-five million
                  (325,000,000), consisting of

                  (1) Twenty-five million (25,000,000) shares of preferred
                  stock, $.10 par value per share (hereinafter "Preferred
                  Stock"); and

                  (2) Three hundred million (300,000,000) shares of common
                  stock, $2.00 par value per share (hereinafter "Common
                  Stock")."

         SECOND: That thereafter, pursuant to resolution of its Board of
Directors, the annual meeting of the stockholders of said corporation was duly
called and held, upon notice in




<PAGE>

accordance with Section 222 of the General Corporation Law of the State of
Delaware, at which meeting the necessary number of shares as required by statute
were voted in favor of the amendment.

         THIRD: That said amendment was duly adopted in accordance with the
provisions of Section 242 of the General Corporation Law of the State of
Delaware.

         FOURTH: That the capital of said corporation will not be reduced under
or by reason of said amendment.

         IN WITNESS WHEREOF, Compass Bancshares, Inc. has caused this
certificate to be executed on this 1st day of May, 2002.

                                COMPASS BANCSHARES, INC.



                                By:    /s/ D. Paul Jones, Jr.
                                   ---------------------------------------------
                                       D. Paul Jones, Jr.
                                       Its Chairman and Chief Executive Officer

ATTEST:


By:      /s/ Jerry W. Powell
     -------------------------
         Jerry W. Powell
         Its Secretary

STATE OF ALABAMA         )
                         )
COUNTY OF JEFFERSON      )

         I, the undersigned Notary Public in and for said County and State, do
hereby certify that on this 1st day of May, 2002, personally appeared before me
D. PAUL JONES, JR., who, being first duly sworn, declared that he is the
Chairman and Chief Executive Officer of Compass Bancshares, Inc., and that,
being informed of the contents, he voluntarily executed the foregoing instrument
in said capacity, as the act and deed of the corporation, and that the
statements made in the foregoing instrument are true.

         WITNESS my hand and official seal on the date aforesaid.

                                      /s/ Melanie Suzanne Henderson
                                     -------------------------------------------
                                     Notary Public
NOTARIAL SEAL
                                     My Commission Expires: August 6, 2003
                                                           --------------------



                                       2