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  xmlns="http://www.xbrl.org/2003/instance"
  xmlns:dei="http://xbrl.sec.gov/dei/2026"
  xmlns:ffd="http://xbrl.sec.gov/ffd/2026"
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    <link:schemaRef
      xlink:href="https://xbrl.sec.gov/ffd/2026/ffd-2026.xsd"
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    <context id="rc">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001781730</identifier>
        </entity>
        <period>
            <startDate>2026-06-22</startDate>
            <endDate>2026-06-22</endDate>
        </period>
    </context>
    <context id="offrl_1">
        <entity>
            <identifier scheme="http://www.sec.gov/CIK">0001781730</identifier>
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                <xbrldi:typedMember dimension="ffd:OfferingAxis">
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        <period>
            <startDate>2026-06-22</startDate>
            <endDate>2026-06-22</endDate>
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    <unit id="USD">
        <measure>iso4217:USD</measure>
    </unit>
    <unit id="pure">
        <measure>pure</measure>
    </unit>
    <unit id="Shares">
        <measure>shares</measure>
    </unit>
    <ffd:FormTp contextRef="rc" id="ixv-168">S-8</ffd:FormTp>
    <ffd:SubmissnTp contextRef="rc" id="ixv-169">S-8</ffd:SubmissnTp>
    <ffd:FeeExhibitTp contextRef="rc" id="ixv-170">EX-FILING FEES</ffd:FeeExhibitTp>
    <dei:EntityCentralIndexKey contextRef="rc" id="ixv-171">0001781730</dei:EntityCentralIndexKey>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-172">Third Coast Bancshares, Inc.</dei:EntityRegistrantName>
    <ffd:OfferingTableNa contextRef="rc" id="hiddenrcOfferingTableNa" xsi:nil="true"/>
    <ffd:OffsetTableNa contextRef="rc" id="hiddenrcOffsetTableNa">N/A</ffd:OffsetTableNa>
    <ffd:PrevslyPdFlg contextRef="offrl_1" id="ixv-175">false</ffd:PrevslyPdFlg>
    <ffd:FormTp contextRef="rc" id="ixv-200">S-8</ffd:FormTp>
    <dei:EntityRegistrantName contextRef="rc" id="ixv-201">Third Coast Bancshares, Inc.</dei:EntityRegistrantName>
    <ffd:OfferingSctyTp contextRef="offrl_1" id="ixv-202">Equity</ffd:OfferingSctyTp>
    <ffd:OfferingSctyTitl contextRef="offrl_1" id="ixv-203">Common Stock, par value $1.00 per share</ffd:OfferingSctyTitl>
    <ffd:FeesOthrRuleFlg contextRef="offrl_1" id="ixv-204">true</ffd:FeesOthrRuleFlg>
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      contextRef="offrl_1"
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      id="ixv-205"
      unitRef="Shares">375000</ffd:AmtSctiesRegd>
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      contextRef="offrl_1"
      decimals="3"
      id="ixv-206"
      unitRef="USD">39.005</ffd:MaxOfferingPricPerScty>
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      contextRef="offrl_1"
      decimals="2"
      id="ixv-207"
      unitRef="USD">14626875.00</ffd:MaxAggtOfferingPric>
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      contextRef="offrl_1"
      decimals="7"
      id="ixv-208"
      unitRef="pure">0.0001381</ffd:FeeRate>
    <ffd:FeeAmt
      contextRef="offrl_1"
      decimals="2"
      id="ixv-209"
      unitRef="USD">2019.98</ffd:FeeAmt>
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    <ffd:TtlFeeAmt contextRef="rc" decimals="2" id="ixv-211" unitRef="USD">2019.98</ffd:TtlFeeAmt>
    <ffd:TtlOffsetAmt contextRef="rc" decimals="2" id="ixv-212" unitRef="USD">0.00</ffd:TtlOffsetAmt>
    <ffd:NetFeeAmt contextRef="rc" decimals="2" id="ixv-213" unitRef="USD">2019.98</ffd:NetFeeAmt>
    <ffd:OfferingNote contextRef="offrl_1" id="ixv-214">(1) Pursuant to Rule 416 under the Securities Act of 1933, as amended (the "Securities Act"), this Registration Statement shall also cover any additional indeterminable number of shares of common stock, par value $1.00 per share ("Common Stock"), that may become issuable under the Amended and Restated Third Coast Bancshares, Inc. 2019 Omnibus Incentive Plan (the "Plan") by reason of any stock dividend, stock split, recapitalization or any other similar transaction. (2) Estimated solely for purposes of calculating the registration fee in accordance with Rules 457(c) and 457(h) under the Securities Act. The maximum offering price per share and the maximum aggregate offering price are based on a price of $39.005 per share, which is the average of the high and low sales prices of shares of Common Stock on The New York Stock Exchange on June 17, 2026.</ffd:OfferingNote>
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