<SEC-DOCUMENT>0001447669-20-000016.txt : 20200213
<SEC-HEADER>0001447669-20-000016.hdr.sgml : 20200213
<ACCEPTANCE-DATETIME>20200213172458
ACCESSION NUMBER:		0001447669-20-000016
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20191231
FILED AS OF DATE:		20200213
DATE AS OF CHANGE:		20200213

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ROTTENBERG ERIKA
		CENTRAL INDEX KEY:			0001284038

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37806
		FILM NUMBER:		20612169

	MAIL ADDRESS:	
		STREET 1:		2029 STIERLIN COURT
		CITY:			MOUNTAIN VIEW
		STATE:			CA
		ZIP:			94043

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TWILIO INC
		CENTRAL INDEX KEY:			0001447669
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		375 BEALE ST
		STREET 2:		SUITE 300
		CITY:			San Francisco
		STATE:			CA
		ZIP:			94105
		BUSINESS PHONE:		650-270-2199

	MAIL ADDRESS:	
		STREET 1:		375 BEALE ST
		STREET 2:		SUITE 300
		CITY:			San Francisco
		STATE:			CA
		ZIP:			94105
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>wf-form5_158163268023547.xml
<DESCRIPTION>FORM 5
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2019-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0001447669</issuerCik>
        <issuerName>TWILIO INC</issuerName>
        <issuerTradingSymbol>TWLO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001284038</rptOwnerCik>
            <rptOwnerName>ROTTENBERG ERIKA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TWILIO INC.</rptOwnerStreet1>
            <rptOwnerStreet2>101 SPEAR STREET, FIRST FLOOR</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94105</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-08-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2185</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </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>2185.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-08-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2185</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2185.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>20279</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of Class B common stock is convertible into one share of Class A common stock at the option of the holder and has no expiration date.</footnote>
        <footnote id="F2">Represents shares that were contributed by the Reporting Person to the Reporting Person's trust.</footnote>
        <footnote id="F3">Represents the shares received by the Reporting Person's trust.</footnote>
        <footnote id="F4">Shares are held by The Erika Rottenberg Revocable Trust.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Shanti Ariker as attorney in fact for Reporting Person</signatureName>
        <signatureDate>2020-02-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>edgartwilio-poaforsection1.txt
<DESCRIPTION>ROTTENBERG POWER OF ATTORNEY
<TEXT>
LIMITED POWER OF ATTORNEY

The undersigned hereby constitutes and appoints each of Karyn Smith,
Shanti Ariker and Ivy Tseng, signing singly, and with full power of
substitution, the undersigned's true and lawful attorney-in-fact to:

    (1)    execute for and on behalf of the undersigned, in
the undersigned's capacity as an officer and/or director of Twilio
Inc. (the "Company"), from time to time the following U.S.Securities
and Exchange Commission ("SEC") forms: (i) Form ID, including any
attached documents, to effect the assignment of codes to the
undersigned to be used in the transmission of information to the SEC
using the EDGAR System; (ii) Form 3, Initial Statement of Beneficial
Ownership of Securities, including any attached documents;  (iii)
Form 4, Statement of Changes in Beneficial Ownership of Securities,
including any attached documents; (iv) Form 5, Annual Statement of
Beneficial Ownership of Securities in accordance with Section 16(a)
of the Securities Exchange Act of 1934, as amended, and the rules
thereunder, including any attached documents; (v) Schedule 13D; (vi)
Schedule 13G and (vii) amendments of each thereof, in accordance
with the Securities Exchange Act of 1934, as amended, and the rules
thereunder, including any attached documents;

    (2)    do and perform any and all acts for and on behalf
of the undersigned which may be necessary or desirable to complete
and execute any such Form 3, 4 or 5, Schedule 13D, Schedule 13G or
any amendment(s) thereto, and timely file such form(s) with the SEC
and any securities exchange, national association or similar
authority; and

    (3)    take any other action of any type whatsoever in
connection with the foregoing which, in the opinion of such attorney-
in-fact, may be of benefit to, in the best interest of, or legally
required by, the undersigned, it being understood that the documents
executed by such attorney-in-fact on behalf of the undersigned
pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve
in such attorney-in-fact's discretion.

The undersigned hereby grants to each such attorney-in-fact, acting
singly, full power and authority to do and perform any and every act
and thing whatsoever requisite, necessary or proper to be done in the
exercise of any of the rights and powers herein granted, as fully to
all intents and purposes as the undersigned might or could do if
personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact, or
such attorney-in-fact's substitute or substitutes, shall lawfully do
or cause to be done by virtue of this Power of Attorney and the rights
and powers herein granted.  The undersigned acknowledges that the
foregoing attorneys-in-fact, in serving in such capacity at the
request of the undersigned, are not assuming, nor is the Company
assuming, any of the undersigned's responsibilities to comply with
Section 16 or Regulation 13D-G of the Securities Exchange Act of 1934,
as amended.  The undersigned hereby agrees to indemnify the attorneys-
in-fact and the Company from and against any demand, damage, loss,
cost or expense arising from any false or misleading information
provided by the undersigned to the attorneys-in-fact.

This Power of Attorney shall remain in full force and effect until
the undersigned is no longer required to file such forms with
respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing attorneys-
in-fact.  This Power of Attorney supersedes any prior power of attorney
in connection with the undersigned's capacity as an officer and/or
director of the Company.  This Power of Attorney shall expire as to
any individual attorney-in-fact if such attorney-in-fact ceases to be
an executive officer of, or legal counsel to the Company.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney
to be executed as of February 13, 2020.

/s/ Erika Rottenberg
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
