<SEC-DOCUMENT>0000899243-21-044896.txt : 20211116
<SEC-HEADER>0000899243-21-044896.hdr.sgml : 20211116
<ACCEPTANCE-DATETIME>20211116185237
ACCESSION NUMBER:		0000899243-21-044896
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20211115
FILED AS OF DATE:		20211116
DATE AS OF CHANGE:		20211116

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Schafer Patrick
		CENTRAL INDEX KEY:			0001772591

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	814-00735
		FILM NUMBER:		211417820

	MAIL ADDRESS:	
		STREET 1:		650 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Portman Ridge Finance Corp
		CENTRAL INDEX KEY:			0001372807
		IRS NUMBER:				205951150
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		650 MADISON AVNUE
		STREET 2:		23RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		212.891.2880

	MAIL ADDRESS:	
		STREET 1:		650 MADISON AVNUE
		STREET 2:		23RD FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KCAP Financial, Inc.
		DATE OF NAME CHANGE:	20120710

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Kohlberg Capital CORP
		DATE OF NAME CHANGE:	20061211

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Kohlberg Capital, LLC
		DATE OF NAME CHANGE:	20060815
</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>2021-11-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001372807</issuerCik>
        <issuerName>Portman Ridge Finance Corp</issuerName>
        <issuerTradingSymbol>PTMN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001772591</rptOwnerCik>
            <rptOwnerName>Schafer Patrick</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PORTMAN RIDGE FINANCE CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>650 MADISON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Investment Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-11-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.0381</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5950</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Reflects the impact of the 1-for-10 reverse stock split effectuated by Portman Ridge Finance Corporation on August 23, 2021.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Patrick Schafer</signatureName>
        <signatureDate>2021-11-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
