<SEC-DOCUMENT>0001209191-21-041865.txt : 20210621
<SEC-HEADER>0001209191-21-041865.hdr.sgml : 20210621
<ACCEPTANCE-DATETIME>20210621120723
ACCESSION NUMBER:		0001209191-21-041865
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20210616
FILED AS OF DATE:		20210621
DATE AS OF CHANGE:		20210621

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GULLO SAMUEL M
		CENTRAL INDEX KEY:			0001211187

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26481
		FILM NUMBER:		211028992

	MAIL ADDRESS:	
		STREET 1:		220 LIBERTY ST
		CITY:			WARSAW
		STATE:			NY
		ZIP:			14569

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FINANCIAL INSTITUTIONS INC
		CENTRAL INDEX KEY:			0000862831
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				160816610
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		220 LIBERTY STREET
		CITY:			WARSAW
		STATE:			NY
		ZIP:			14569
		BUSINESS PHONE:		5857861100

	MAIL ADDRESS:	
		STREET 1:		220 LIBERTY STREET
		CITY:			WARSAW
		STATE:			NY
		ZIP:			14569
</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>2021-06-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000862831</issuerCik>
        <issuerName>FINANCIAL INSTITUTIONS INC</issuerName>
        <issuerTradingSymbol>FISI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001211187</rptOwnerCik>
            <rptOwnerName>GULLO SAMUEL M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>220 LIBERTY STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WARSAW</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>14569</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>2021-06-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>935</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29095</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-06-16</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>779</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.06</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29874</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>W. Jack Plants II, by power of attorney</signatureName>
        <signatureDate>2021-06-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24.4_994260
<SEQUENCE>2
<FILENAME>poa.txt
<DESCRIPTION>POA DOCUMENT
<TEXT>
LIMITED POWER OF ATTORNEY FOR SECTION 16 REPORTING OBLIGATIONS


      The undersigned hereby constitutes and appoints each of Michael D. Grover,
Sonia M. Dumbleton and W. Jack Plants II as the undersigned's true and lawful
attorney-in-fact, and grants each of them full power to act on behalf of the
undersigned and in the undersigned's name, place and stead, for the purpose of
completing and signing, on behalf of the undersigned, any Form 3, Form 4 or Form
5 (including any amendments thereto) required or permitted to be filed by the
undersigned pursuant to Section 16 of the Securities Exchange Act of 1934, as
amended (the "Exchange Act"), with regard to the undersigned's holdings of or
transactions in the securities of Financial Institutions, Inc., and to file such
forms (and amendments thereto) with the Securities and Exchange Commission, and
to do and perform each and every act and thing requisite or necessary to be done
in connection with such forms (and amendments thereto,) as fully and to all
intents and purposes as the undersigned might or could do in person.

      The authority of Michael D. Grover, Sonia M. Dumbleton and W. Jack Plants
II under this Limited Power of Attorney shall continue until the undersigned is
no longer required to file forms under Section 16(a) of the Exchange Act with
regard to the undersigned's holdings of or transactions in the securities of
Financial Institutions, Inc., unless earlier revoked by the undersigned in
writing.

      The undersigned acknowledges that Michael D. Grover, Sonia M. Dumbleton
and W. Jack Plants II are not assuming any of the undersigned's responsibilities
to comply with Section 16 of the Exchange Act.


/s/ Samuel M. Gullo
Signature
Name:  Samuel M. Gullo
Date:  June 1, 2021
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
