<SEC-DOCUMENT>0000921895-21-000558-index.html : 20210225
<SEC-HEADER>0000921895-21-000558.hdr.sgml : 20210225
<ACCEPTANCE-DATETIME>20210225172231
ACCESSION NUMBER:		0000921895-21-000558
CONFORMED SUBMISSION TYPE:	SC 13D/A
PUBLIC DOCUMENT COUNT:		3
FILED AS OF DATE:		20210225
DATE AS OF CHANGE:		20210225

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ACI WORLDWIDE, INC.
		CENTRAL INDEX KEY:			0000935036
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				470772104
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-45029
		FILM NUMBER:		21681842

	BUSINESS ADDRESS:	
		STREET 1:		3520 KRAFT ROAD, SUITE 300
		CITY:			NAPLES
		STATE:			FL
		ZIP:			34105
		BUSINESS PHONE:		239-403-4600

	MAIL ADDRESS:	
		STREET 1:		3520 KRAFT ROAD, SUITE 300
		CITY:			NAPLES
		STATE:			FL
		ZIP:			34105

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TRANSACTION SYSTEMS ARCHITECTS INC
		DATE OF NAME CHANGE:	19950109

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Starboard Value LP
		CENTRAL INDEX KEY:			0001517137
		IRS NUMBER:				000000000

	FILING VALUES:
		FORM TYPE:		SC 13D/A

	BUSINESS ADDRESS:	
		STREET 1:		777 THIRD AVENUE, 18TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10017
		BUSINESS PHONE:		(212) 845-7977

	MAIL ADDRESS:	
		STREET 1:		777 THIRD AVENUE, 18TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10017
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D/A
<SEQUENCE>1
<FILENAME>sc13da206297289_02252021.htm
<DESCRIPTION>AMENDMENT NO. 2 TO THE SCHEDULE 13D
<TEXT>
Document 1 - file: sc13da206297289_02252021.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>ex991to13da206297289_022521.htm
<DESCRIPTION>AGREEMENT, DATED FEBRUARY 24, 2021
<TEXT>
Document 2 - file: ex991to13da206297289_022521.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>image_002.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: image_002.jpg

</DOCUMENT>
</SEC-DOCUMENT>