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    <dei:EntityRegistrantName contextRef="c0" id="ixv-5521">TMC THE METALS COMPANY INC.</dei:EntityRegistrantName>
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    <ecd:RestatementDoesNotRequireRecoveryTextBlock contextRef="c1" id="ixv-2162">&lt;div style="margin-top:12pt; width:456pt; line-height:12pt;font-weight:bold;"&gt; &lt;span style="letter-spacing:-0.022pt;"&gt;Clawback Policy&lt;/span&gt;&lt;span style="font-weight:normal;font-family:Times New Roman, Times, serif ;letter-spacing:0.2pt;"&gt; &lt;/span&gt; &lt;/div&gt;&lt;div style="text-indent:20pt; margin-top:8pt; text-align:justify; width:456pt; line-height:12pt;"&gt;
          &lt;span style="letter-spacing:-0.075pt;"&gt;We believe that it is in our best interests and that of our shareholders to create and maintain a culture that emphasizes integrity and accountability and therefore, in compliance with SEC and Nasdaq rules, we adopted a clawback policy that is administered by the compensation committee and which provides for the recoupment of certain executive compensation in the event of an accounting restatement resulting from material noncompliance with financial reporting requirements under the federal securities laws. Our clawback policy provides for the mandatory reimbursement or recovery, from current and former officers, of excess incentive-based compensation that was erroneously awarded during the three&#160;years preceding the date that we are required to prepare certain accounting restatements of our financial statements.&lt;/span&gt;&lt;span style="font-family:Times New Roman, Times, serif ;letter-spacing:0.2pt;"&gt; &lt;/span&gt;
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          &lt;span style="letter-spacing:-0.075pt;"&gt;As previously disclosed, in March 2024, we identified errors in the financial statements and related disclosures in our Quarterly Reports on Form&#160;10-Q for the quarter ended March 31, 2023, for the six months ended June 30, 2023 and nine months ended September&#160;30, 2023 and revised these financial statements in our Annual Report on Form&#160;10-K for the year ended December&#160;31, 2023, after which, management concluded that no adjustments to executive compensation were required because no compensation was paid to the executive officers under performance-based compensation awards pursuant to any performance goals impacted by the revisions and, therefore, that there was no excess incentive-based compensation to recover.&lt;/span&gt;
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    <ecd:AwardTmgMnpiDiscTextBlock contextRef="c0" id="ixv-4070">&lt;div style="text-indent:20pt; margin-top:8pt; text-align:justify; width:456pt; line-height:12pt;"&gt; &lt;span style="letter-spacing:-0.075pt;"&gt;LTIP and other incentive awards for 2024 were made on February&#160;26, 2025 at a regularly scheduled meeting of the compensation committee, and the compensation committee anticipates continuing to grant LTIP awards generally in February of each year going forward. The compensation committee and the board of directors does not time the grant of equity compensation with regards to the release of material nonpublic information, whether or not that information may favorably or unfavorably impact the price of our common shares. Similarly, we do not time the release of material nonpublic information based on equity award grant dates. Equity awards for the executive officers, including our Chief Executive Officer, are approved by the compensation committee. We did not grant options to any of our executive officers during 2024.&lt;/span&gt;&lt;span style="font-family:Times New Roman, Times, serif ;letter-spacing:0.2pt;"&gt; &lt;/span&gt; &lt;/div&gt;</ecd:AwardTmgMnpiDiscTextBlock>
    <ecd:AwardTmgMethodTextBlock contextRef="c0" id="ixv-5523">LTIP and other incentive awards for 2024 were made on February&#160;26, 2025 at a regularly scheduled meeting of the compensation committee, and the compensation committee anticipates continuing to grant LTIP awards generally in February of each year going forward.</ecd:AwardTmgMethodTextBlock>
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    <ecd:AwardTmgHowMnpiCnsdrdTextBlock contextRef="c0" id="ixv-5525">The compensation committee and the board of directors does not time the grant of equity compensation with regards to the release of material nonpublic information, whether or not that information may favorably or unfavorably impact the price of our common shares. Similarly, we do not time the release of material nonpublic information based on equity award grant dates.</ecd:AwardTmgHowMnpiCnsdrdTextBlock>
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