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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-09-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001647088</issuerCik>
        <issuerName>WillScot Corp</issuerName>
        <issuerTradingSymbol>WSC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001207119</rptOwnerCik>
            <rptOwnerName>SAGANSKY JEFFREY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>901 S. BOND STREET, #600</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BALTIMORE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21231</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-09-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>124999</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3369295</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-09-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>665938</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2703357</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Private Placement Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-09-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>970000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>485000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3880000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Private Placement Warrants</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-09-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>50000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3980000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents a transfer of 124,999 shares of Class A Common Stock of the Company from Double Eagle Acquisition LLC (&quot;DEAL&quot;) to Harry E. Sloan. As managing member of DEAL, Mr. Sagansky may be deemed the beneficial owner of shares of Class A Common Stock held by DEAL (including the 124,999 shares disposed of in the Reported Transaction).</footnote>
        <footnote id="F2">30,000 shares of Class A Common Stock beneficially owned following the reported transaction were previously acquired by Mr. Sagansky as reported on a Form 4 filed with the Securities and Exchange Commission on September 15, 2017; 3,690 shares of Class A Common Stock beneficially owned following the reported transaction were previously acquired by Mr. Sagansky as reported on a Form 4 filed with the Securities and Exchange Commission on March 22, 2018; 5,917 shares of Class A Common Stock beneficially owned following the reported transaction were previously acquired by Mr. Sagansky as reported on a Form 4 filed with the Securities and Exchange Commission on August 30, 2018. The remaining shares of Class A Common Stock beneficially owned following the Reported Transaction are held by DEAL. As managing member of DEAL, Mr. Sagansky may be deemed the beneficial owner of shares of Class A Common Stock held by DEAL.</footnote>
        <footnote id="F3">Represents pro rata distribution from DEAL to its members. As managing member of DEAL, Mr. Sagansky may be deemed the beneficial owner of shares of Class A Common Stock held by DEAL (including the 665,938 shares disposed of in the Reported Transaction). The remaining shares of Class A Common Stock (2,663,700 shares) were distributed to Mr. Sagansky.</footnote>
        <footnote id="F4">Represents pro rata distribution from DEAL to its members. As managing member of DEAL, Mr. Sagansky may be deemed the beneficial owner of shares of the Private Placement Warrants held by DEAL (including the 970,000 Private Placement Warrants disposed of in the Reported Transaction). The remaining Private Placement Warrants (3,880,000 warrants) were distributed to Mr. Sagansky.</footnote>
        <footnote id="F5">The Private Placement Warrants became exercisable on December 29, 2017 and expire at 5pm, New York City time, on November 29, 2022, or earlier upon redemption or liquidation.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Bradley L. Bacon, as Attorney-in-Fact on behalf of Jeffrey Sagansky</signatureName>
        <signatureDate>2018-09-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
