<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2022-08-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001650164</issuerCik>
        <issuerName>Toast, Inc.</issuerName>
        <issuerTradingSymbol>TOST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001655213</rptOwnerCik>
            <rptOwnerName>Bessemer Venture Partners IX L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVENUE, SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001624149</rptOwnerCik>
            <rptOwnerName>Bessemer Venture Partners IX Institutional L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVENUE, SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001655220</rptOwnerCik>
            <rptOwnerName>Deer IX &amp; Co. Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVE., SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001655219</rptOwnerCik>
            <rptOwnerName>Deer IX &amp; Co. L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVENUE, SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001787478</rptOwnerCik>
            <rptOwnerName>Bessemer Venture Partners Century Fund L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVENUE, SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001787477</rptOwnerCik>
            <rptOwnerName>Bessemer Venture Partners Century Fund Institutional L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVENUE, SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001768677</rptOwnerCik>
            <rptOwnerName>Deer X &amp; Co. Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVENUE, SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001768637</rptOwnerCik>
            <rptOwnerName>Deer X &amp; Co. L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O BESSEMER VENTURE PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>1865 PALMER AVENUE, SUITE 104</rptOwnerStreet2>
            <rptOwnerCity>LARCHMONT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10538</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-08-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4470349</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4470349</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-08-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F6"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4470349</value>
                    <footnoteId id="F6"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F6"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2022-08-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4470349</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4470349</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>43213375</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each outstanding share of Class B Common Stock is convertible into one share of Class A Common Stock at any time at the option of the holder or automatically upon the occurrence of other events set forth in the Issuer's certificate of incorporation.</footnote>
        <footnote id="F2">Represents 2,481,938 shares converted from Class B Common Stock to Class A Common Stock by Bessemer Venture Partners IX, L.P. (&quot;Bessemer IX&quot;), and 1,988,411 shares converted from Class B Common Stock to Class A Common Stock by Bessemer Venture Partners IX Institutional, L.P. (&quot;Bessemer Institutional&quot;, and together with Bessemer IX, the &quot;Bessemer IX Funds&quot;).</footnote>
        <footnote id="F3">Deer IX &amp; Co. Ltd. (&quot;Deer IX Ltd.&quot;) is the general partner of Deer IX &amp; Co. L.P. (&quot;Deer IX L.P.&quot;), which is the general partner of each of the Bessemer IX Funds. Deer IX Ltd. and Deer IX L.P. disclaim beneficial ownership of the securities held by the Bessemer IX Funds, and this report shall not be deemed an admission that Deer IX Ltd. and Deer IX L.P. are the beneficial owners of such securities, except to the extent of their pecuniary interest therein, if any, by virtue of their direct and indirect general partner interests in the Bessemer IX Funds.</footnote>
        <footnote id="F4">Deer X &amp; Co. Ltd. (&quot;Deer X Ltd.&quot;) is the general partner of Deer X &amp; Co. L.P. (&quot;Deer X L.P.&quot;), which is the general partner of each of Bessemer Venture Partners Century Fund L.P. (&quot;Bessemer Century&quot;) and Bessemer Venture Partners Century Fund Institutional L.P. (&quot;Bessemer Century Institutional&quot;, and together with Bessemer Century, the &quot;Bessemer Century Funds&quot;). Deer X Ltd. and Deer X L.P. disclaim beneficial ownership of the securities held by the Bessemer Century Funds, and this report shall not be deemed an admission that Deer X Ltd. and Deer X L.P. are the beneficial owners of such securities, except to the extent of their pecuniary interest therein, if any, by virtue of their direct and indirect general partner interests in the Bessemer Century Funds.</footnote>
        <footnote id="F5">As of the date hereof, Bessemer IX, Bessemer Institutional, Bessemer Century and Bessemer Century Institutional own 21,548,921 shares of Class B Common Stock, 17,263,979 shares of Class B Common Stock, 601,985 shares of Class B Common Stock, and 3,798,490 shares of Class B Common Stock, respectively.</footnote>
        <footnote id="F6">On August 17, 2022 Bessemer IX and Bessemer Institutional distributed, for no consideration 2,481,938 shares and 1,988,411 shares, respectively (collectively, the &quot;Shares&quot;), of Class A Common Stock to their limited partners and to Deer IX L.P., representing each such partner's pro rata interest in such Shares. On the same date, one or more of such limited partner(s) distributed, for no consideration, the Shares to certain of its or their members in an amount equal to each such member's or members' respective pro rata interests in the Shares. Finally, on the same date, Deer IX L.P. distributed, for no consideration, the Shares it received from the distributions to its partners in an amount equal to each such partner's pro rata interest in the Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer IX &amp; Co. Ltd., the General Partner of Deer IX &amp; Co. L.P., the General Partner of Bessemer Venture Partners IX L.P.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer IX &amp; Co. Ltd., the General Partner of Deer IX &amp; Co. L.P., the General Partner of Bessemer Venture Partners IX Institutional L.P.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer X &amp; Co. Ltd., the General Partner of Deer X &amp; Co. L.P., the General Partner of Bessemer Venture Partners Century Fund L.P.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer X &amp; Co. Ltd., the General Partner of Deer X &amp; Co. L.P., the General Partner of Bessemer Venture Partners Century Fund Institutional L.P.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer IX &amp; Co. Ltd., the General Partner of Deer IX &amp; Co. L.P.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer IX &amp; Co. Ltd.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer X &amp; Co. Ltd., the General Partner of Deer X &amp; Co. L.P.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Scott Ring, General Counsel, Deer X &amp; Co. Ltd.</signatureName>
        <signatureDate>2022-08-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
