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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 VFVJ8/sFImjIcdp+fIq/NF8YSCIzDOjeLv+TPDZ9V3kTpb11RdU0dZj1NW7UoEQl
 IAEKMpD4uPVlXgy97K0A+A==

<SEC-DOCUMENT>0001269847-09-000006.txt : 20090511
<SEC-HEADER>0001269847-09-000006.hdr.sgml : 20090511
<ACCEPTANCE-DATETIME>20090511145805
ACCESSION NUMBER:		0001269847-09-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090508
FILED AS OF DATE:		20090511
DATE AS OF CHANGE:		20090511

ISSUER:		

	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:			0930

	BUSINESS ADDRESS:	
		STREET 1:		120 BROADWAY, SUITE 3350
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10271
		BUSINESS PHONE:		402-390-7600

	MAIL ADDRESS:	
		STREET 1:		120 BROADWAY, SUITE 3350
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10271

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HEASLEY PHILIP G
		CENTRAL INDEX KEY:			0001078558

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-25346
		FILM NUMBER:		09814361

	MAIL ADDRESS:	
		STREET 1:		ACI WORLDWIDE, INC.
		STREET 2:		6060 COVENTRY DRIVE
		CITY:			ELKHORN
		STATE:			NE
		ZIP:			68022
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-05-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000935036</issuerCik>
        <issuerName>ACI WORLDWIDE, INC.</issuerName>
        <issuerTradingSymbol>ACIW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001078558</rptOwnerCik>
            <rptOwnerName>HEASLEY PHILIP G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>120 BROADWAY</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 3350</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10271</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO and President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-05-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1092</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>258972</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The purchase price ranged from $14.1063 to $14.11 with an average purchase price of $14.1095.  The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected.</footnote>
        <footnote id="F2">The amount of securities owned has also been updated to include 483 shares acquired on January 30, 2009 and 489 shares aquired on April 30, 2009 pursuant to the ACI Worldwide, Inc. 1999 Employee Stock Purchase Plan, as amneded.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: /s/ Victoria H Finley, Attorney in Fact  For: Philip G Heasley</signatureName>
        <signatureDate>2009-05-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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