POWER OF ATTORNEY

Know all by these presents, that the undersigned hereby constitutes and
appoints Dennis Byrnes the undersigned's true and lawful
attorney-in-fact to:

(1)	execute for and on behalf of the undersigned, in the undersigned's
capacity as an officer and/or director of ACI Worldwide, Inc.
(the "Company"), Forms 3, 4, and 5 in accordance with Section 16(a) of the
Securities Exchange Act of 1934 and the rules thereunder;
(2)	do and perform any and all acts for and on behalf of the undersigned
which may be necessary or desirable to complete and execute any such Form 3,
4, or 5, complete and execute any amendment or amendments thereto, and timely
file such form with the United States Securities and Exchange Commission and
any stock exchange or similar authority; and
(3)	take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of
the undersigned pursuant to this Power of Attorney shall be in such form and
shall contain such terms and conditions as such attorney-in-fact may approve
in such attorney-in-fact's discretion. The undersigned hereby grants to each
such attorney-in-fact full power and authority to do and perform any and every
act and thing whatsoever requisite, necessary, or proper to be done in the
exercise of any of the rights and powers herein granted, as fully to all
intents and purposes as the undersigned might or could do if personally
present, with full power of substitution or revocation, hereby ratifying and
confirming all that such attorney-in-fact, or such attorney-in-fact's
substitute or substitutes, shall lawfully do or cause to be done by virtue of
this power of attorney and the rights and powers herein granted. The
undersigned acknowledges that the foregoing attorneys-in-fact, in serving in
such capacity at the request of the undersigned, are not assuming, nor is the
Company assuming, any of the undersigned's responsibilities to comply with
Section 16 of the Securities Exchange Act of 1934.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to
the undersigned's holdings of and transactions in securities issued by the
Company, unless earlier revoked by the undersigned in a signed
writing delivered to the foregoing attorneys-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 5th day of October 2022.


/s/ Janet Estep
Signature
Janet O Estep
Printed Name