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    <schemaVersion>X0306</schemaVersion>

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    <periodOfReport>2021-06-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001826000</issuerCik>
        <issuerName>Latch, Inc.</issuerName>
        <issuerTradingSymbol>LTCH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001864918</rptOwnerCik>
            <rptOwnerName>Jones Michael Brian</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LATCH, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>508 WEST 26TH STREET, SUITE 6G</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10001</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Technology Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

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                <value>Common Stock</value>
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                <transactionFormType>4</transactionFormType>
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                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
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                <directOrIndirectOwnership>
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                </directOrIndirectOwnership>
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    <derivativeTable>
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            <expirationDate>
                <value>2025-02-08</value>
            </expirationDate>
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                <underlyingSecurityTitle>
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            <expirationDate>
                <value>2026-05-11</value>
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            <deemedExecutionDate></deemedExecutionDate>
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                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
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                <transactionShares>
                    <value>1514682</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
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                    <value>A</value>
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            <exerciseDate>
                <footnoteId id="F3"/>
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            <expirationDate>
                <value>2028-11-06</value>
            </expirationDate>
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                <underlyingSecurityTitle>
                    <value>Common Stock</value>
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                <underlyingSecurityShares>
                    <value>1514682</value>
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                    <value>1514682</value>
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    <footnotes>
        <footnote id="F1">Pursuant to the business combination of TS Innovation Acquisitions Corp. and Latch, Inc. (&quot;Legacy Latch&quot;), each share of Legacy Latch outstanding common and preferred stock and each outstanding convertible note was automatically converted into the right to receive shares of the Issuer's Common Stock based on a 1-to-0.8971 conversion ratio (the &quot;Conversion Ratio&quot;). In addition, each outstanding Legacy Latch equity award was automatically converted into a corresponding equity award of the Issuer based on the Conversion Ratio and with the same terms and vesting conditions as the Legacy Latch equity awards.</footnote>
        <footnote id="F2">The stock option is fully vested.</footnote>
        <footnote id="F3">The stock option is currently vested and exercisable as to 1,041,343 of the underlying shares, and the remaining shares will vest in equal monthly installments until fully vested on August 9, 2022.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Priyen Patel, Attorney-in-fact</signatureName>
        <signatureDate>2021-06-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
