<SEC-DOCUMENT>0001209191-21-033132.txt : 20210517
<SEC-HEADER>0001209191-21-033132.hdr.sgml : 20210517
<ACCEPTANCE-DATETIME>20210517161519
ACCESSION NUMBER:		0001209191-21-033132
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210513
FILED AS OF DATE:		20210517
DATE AS OF CHANGE:		20210517

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ryan Owen
		CENTRAL INDEX KEY:			0001748906

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37924
		FILM NUMBER:		21930785

	MAIL ADDRESS:	
		STREET 1:		C/O BLACKLINE INC
		STREET 2:		21300 VICTORY BOULEVARD 12TH FLOOR
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BLACKLINE, INC.
		CENTRAL INDEX KEY:			0001666134
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				463354276
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		21300 VICTORY BOULEVARD
		STREET 2:		12TH FLOOR
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367
		BUSINESS PHONE:		818-223-9008

	MAIL ADDRESS:	
		STREET 1:		21300 VICTORY BOULEVARD
		STREET 2:		12TH FLOOR
		CITY:			WOODLAND HILLS
		STATE:			CA
		ZIP:			91367
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-05-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001666134</issuerCik>
        <issuerName>BLACKLINE, INC.</issuerName>
        <issuerTradingSymbol>BL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001748906</rptOwnerCik>
            <rptOwnerName>Ryan Owen</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BLACKLINE, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>21300 VICTORY BLVD., 12TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>WOODLAND HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91367</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-05-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1847</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10011</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Reflects automatic annual restricted stock unit (&quot;RSU&quot;) awards pursuant to the Issuer's Outside Director Compensation Policy.</footnote>
        <footnote id="F2">The reported securities awarded on May 13, 2021 (the &quot;Award Date&quot;) represent RSUs which vest in full upon the earlier of the one (1) year anniversary of the Award Date or the day prior to the Issuer's next annual meeting of the stockholders and in each case subject to the Reporting Person's continued service on the Issuer's board of directors through each vesting date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Karole Morgan-Prager, Attorney-in-Fact</signatureName>
        <signatureDate>2021-05-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
