Description of Organization and Business Operations	6 Months Ended
Jun. 30, 2026
Description of Organization and Business Operations [Abstract]
DESCRIPTION OF ORGANIZATION AND BUSINESS OPERATIONS	NOTE 1. DESCRIPTION OF ORGANIZATION AND BUSINESS OPERATIONS Metals Acquisition Corp. II (the “Company”) is a blank check company incorporated in the Cayman Islands on November 28, 2025. The Company was incorporated for the purpose of entering into a merger, amalgamation, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses (a “Business Combination”). The Company is not limited to a particular industry or geographic region for purposes of consummating a Business Combination. The Company is an early stage and emerging growth company and, as such, the Company is subject to all of the risks associated with early stage and emerging growth companies. As of June 30, 2026, the Company had not commenced any operations. All activity for the period from November 28, 2025 (inception) through June 30, 2026 relates to the Company’s formation, the Initial Public Offering (“Initial Public Offering”), which is described below, and subsequent to the Initial Public Offering, identifying a target company for a Business Combination. The Company will not generate any operating revenues until after the completion of a Business Combination, at the earliest. The Company generates non-operating income in the form of interest income from the proceeds derived from the Initial Public Offering. The Company’s sponsor is MAC Partners LLC, a Cayman Islands limited liability company (the “Sponsor”). The registration statement for the Company’s Initial Public Offering was declared effective on March 11, 2026. On March 13, 2026, the Company consummated the Initial Public Offering of 23,000,000 units (the “Units”), which includes the full exercise by the underwriters of their over-allotment option of 3,000,000 Units, at $10.00 per Unit, generating gross proceeds of $230,000,000. Each Unit consists of one Class A ordinary share and one-third of one redeemable warrant (each “Public Warrant”, and collectively the “Public Warrants”). Each whole Public Warrant entitles the holder thereof to purchase one Class A ordinary share at a price of $11.50 per share, subject to adjustment. Simultaneously with the closing of the Initial Public Offering, the Company consummated the sale of an aggregate of 5,066,666 Private Placement Warrants (each “Private Placement Warrant”, collectively the “Private Placement Warrants”) at a price of $1.50 per Private Placement Warrant, generating gross proceeds of $7,600,000. Of those 5,066,666 Private Placement Warrants, the Sponsor purchased 3,533,333 Private Placement Warrants, Cohen & Company Capital Markets, a division of Cohen & Company Securities, LLC (“Cohen” or the “Representative”) purchased 1,226,666 Private Placement Warrants, Jett Capital Advisors, LLC purchased 230,000 Private Placement Warrants and Sternship Advisers Pty Ltd purchased 76,667 Private Placement Warrants. Transaction costs amounted to $14,481,900, consisting of $4,600,000 of cash underwriting fees, $9,200,000 of deferred underwriting fees, and $681,900 of other offering costs. The Company’s management has broad discretion with respect to the specific application of the net proceeds of the Initial Public Offering and the sale of the Private Placement Warrants, although substantially all of the net proceeds are intended to be applied generally toward consummating a Business Combination. There is no assurance that the Company will be able to complete a Business Combination successfully. The Company must complete a Business Combination with one or more target businesses that together have an aggregate fair market value of at least 80% of the value of the Trust Account (as defined below) (excluding the deferred underwriting commissions and taxes paid or payable on the interest earned on the Trust Account) on the date of the execution of a definitive agreement into an initial Business Combination. The Company will only complete a Business Combination if the post-transaction company owns or acquires 50% or more of the outstanding voting securities of the target or otherwise acquires a controlling interest in the target sufficient for it not to be required to register as an investment company under the Investment Company Act of 1940, as amended (the “Investment Company Act”). Following the closing of the Initial Public Offering, on March 13, 2026, an amount of $230,000,000 ($10.00 per Unit) from the net proceeds of the sale of the Units and the Private Placement Warrants was placed in the trust account (the “Trust Account”), with U.S.-based trust account, Continental Stock Transfer & Trust Company, acting as trustee. The funds held in the Trust Account are invested, at the Company’s election, in (i) U.S. government treasury obligations with a maturity of 185 days or less, (ii) money market funds meeting certain conditions under Rule 2a-7 under the Investment Company Act, which invest only in direct U.S. government treasury obligations, or (iii) interest-bearing demand deposit accounts or cash held in deposit accounts, in each case until the earlier of (i) the completion of a Business Combination and (ii) the distribution of the funds held in the Trust Account, as described below. The Company will provide its holders of the outstanding Public Shares (the “public shareholders”) with the opportunity to redeem all or a portion of their Public Shares upon the completion of a Business Combination either (i) in connection with a shareholder meeting called to approve the Business Combination or (ii) without a shareholder vote by means of a tender offer. The decision as to whether the Company will seek shareholder approval of a Business Combination or conduct a tender offer will be made by the Company, solely in its discretion, and will be based on a variety of factors such as the timing of the transaction and whether the terms of the transaction would require the Company to seek shareholder approval under applicable law or stock exchange listing requirements. The public shareholders will be entitled to redeem their Public Shares for a pro rata portion of the amount then in the Trust Account (initially anticipated to be $10.00 per Public Share, plus any pro rata interest earned on the funds held in the Trust Account and not previously released to the Company to pay its tax obligations and up to $100,000 of interest to pay liquidation expenses). There will be no redemption rights upon the completion of a Business Combination with respect to the Company’s warrants. The Public Shares subject to redemption will be recorded at redemption value and classified as temporary equity upon the completion of the Initial Public Offering in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 480, Distinguishing Liabilities from Equity (“ASC 480”). The Company will proceed with a Business Combination only if the majority of the shares voted are voted in favor of the Business Combination. If a shareholder vote is not required by law and the Company does not decide to hold a shareholder vote for business or other reasons, the Company will, pursuant to its amended and restated memorandum and articles of association (the “Amended and Restated Memorandum and Articles of Association”), conduct the redemptions pursuant to the tender offer rules of the U.S. Securities and Exchange Commission (“SEC”) and file tender offer documents with the SEC prior to completing a Business Combination. If, however, shareholder approval of the transaction is required by law, or the Company decides to obtain shareholder approval for business or other reasons, the Company will offer to redeem shares in conjunction with a proxy solicitation pursuant to the proxy rules and not pursuant to the tender offer rules. If the Company seeks shareholder approval in connection with a Business Combination, the Sponsor has agreed to vote its Founder Shares (as defined in Note 5) and any Public Shares purchased during or after the Initial Public Offering in favor of approving a Business Combination. Additionally, each public shareholder may elect to redeem their Public Shares irrespective of whether they vote for or against the proposed transaction or do not vote at all. Notwithstanding the above, if the Company seeks shareholder approval of a Business Combination and the Company does not conduct redemptions pursuant to the tender offer rules, the Amended and Restated Memorandum and Articles of Association provides that a public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from redeeming its shares with respect to more than an aggregate of 15% or more of the Public Shares, without the prior consent of the Company. The Sponsor has agreed to waive redemption rights with respect to any Founder Shares (as defined in Note 5) held and any Public Shares they may acquire during or after the Initial Public Offering in connection with the completion of Business Combination, except that Public Shares held by the initial shareholder will be subject to mandatory redemption upon any diminution of the Trust Account in connection with an extension, and such shares will be entitled to redemption at a price equal to the per share redemption value then held in the Trust Account in connection therewith. The Company will have until 24 months from the closing of the Initial Public Offering to complete a Business Combination (the “completion window”). However, if the Company anticipates that it may not be able to consummate a Business Combination within 24 months from the closing of the Initial Public Offering, the Company may, but is not obligated to, by resolution of the board if requested by the initial shareholder, extend the period of time to consummate a Business Combination the Company may seek shareholder approval to amend the amended and restated memorandum and articles of association to extend the date by which the Company must consummate the initial Business Combination. If the Company seeks shareholder approval for an extension, holders of Public Shares will be offered an opportunity to redeem their shares, regardless of whether they abstain, vote for, or against, the Company’s initial Business Combination, at a per share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned thereon (which interest shall be net of taxes paid or payable (excluding any 1% U.S. federal excise tax on stock repurchases under the Inflation Reduction Act of 2022, or similar tax, that is imposed on the Company, if any) and up to $100,000 of interest to pay liquidation expenses) and not previously released to the Company pursuant to permitted withdrawals, divided by the number of then issued and outstanding Public Shares, which redemption will completely extinguish Public Shareholders’ rights as shareholders (including the right to receive further liquidating distributions, if any), subject to applicable law. For the avoidance of doubt, the time to complete a Business Combination shall not be extended beyond 24 months without a shareholder vote. The underwriters have agreed to waive their rights to their deferred underwriting commission held in the Trust Account in the event the Company does not complete a Business Combination within the completion window and, in such event, such amounts will be included with the other funds held in the Trust Account that will be available to fund the redemption of the Public Shares. In order to protect the amounts held in the Trust Account, the Sponsor has agreed that it will be liable to the Company if and to the extent any claims by a third party for services rendered or products sold to the Company, or a prospective target business with which the Company has entered into a written letter of intent, confidentiality or other similar agreement or Business Combination agreement (except for the Company’s independent registered public accounting firm), reduce the amount of funds in the Trust Account to below the lesser of (i) $10.00 per Public Share and (ii) the actual amount per Public Share held in the Trust Account as of the date of the liquidation of the Trust Account, if less than $10.00 per Public Share due to reductions in the value of the trust assets, less taxes paid or payable and up to $100,000 of interest to pay liquidation expenses, provided that such liability will not apply to any claims by a third party or prospective target business who executed a waiver of any and all rights to the monies held in the Trust Account (whether or not such waiver is enforceable) nor will it apply to any claims under the indemnity of the underwriters of the Initial Public Offering against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”). Subsequent to March 31, 2026, the Company directed Continental Stock Transfer & Trust Company (“Continental”), as trustee, to reinvest the funds held in the Trust Account from an interest-bearing demand deposit account into U.S. government treasury obligations with a maturity of 185 days or less, in accordance with the investment options permitted under the Company’s Investment Management Trust Agreement with Continental, signed in connection with the Initial Public Offering (the “Trust Agreement”). This change does not affect the amount held in the Trust Account or the Company’s ability to complete a Business Combination within the completion window. Liquidity, Capital Resources and Going Concern The Company’s liquidity needs up to June 30, 2026 had been satisfied through the loan under an unsecured promissory note from the Sponsor of up to $300,000 (the “Promissory Note”) (see Note 5) and the proceeds from the sale of Private Placement Warrants in a private placement to the Sponsor, Cohen & Company Capital Markets, Jett Capital Advisors, LLC and Sternship Advisers Pty Ltd. At June 30, 2026, the Company had cash of $1,889,425 and a working capital surplus of $1,784,775. In connection with the Company’s assessment of going concern in accordance with FASB ASC 205-40, Presentation of Financial Statements - Going Concern, the Company does not believe it will need to raise additional funds in order to meet the expenditures required to operate its business. However, if the estimate of the costs of identifying a target business, undertaking in-depth due diligence and negotiating a Business Combination are less than the actual amount necessary to do so, the Company may have insufficient funds available to operate its business prior to the Initial Business Combination. Management has determined that upon the consummation of the Initial Public Offering and the sale of the Private Placement Warrants, the Company has sufficient funds to finance the working capital needs of the Company within one year from the date of issuance of the financial statements.

Description of Organization and Business Operations

6 Months Ended

Jun. 30, 2026

Description of Organization and Business Operations [Abstract]

DESCRIPTION OF ORGANIZATION AND BUSINESS OPERATIONS

NOTE 1. DESCRIPTION OF ORGANIZATION AND BUSINESS OPERATIONS

Metals Acquisition Corp. II (the “Company”) is a blank check company incorporated in the Cayman Islands on November 28, 2025. The Company was incorporated for the purpose of entering into a merger, amalgamation, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses (a “Business Combination”). The Company is not limited to a particular industry or geographic region for purposes of consummating a Business Combination. The Company is an early stage and emerging growth company and, as such, the Company is subject to all of the risks associated with early stage and emerging growth companies.

As of June 30, 2026, the Company had not commenced any operations. All activity for the period from November 28, 2025 (inception) through June 30, 2026 relates to the Company’s formation, the Initial Public Offering (“Initial Public Offering”), which is described below, and subsequent to the Initial Public Offering, identifying a target company for a Business Combination. The Company will not generate any operating revenues until after the completion of a Business Combination, at the earliest. The Company generates non-operating income in the form of interest income from the proceeds derived from the Initial Public Offering.

The Company’s sponsor is MAC Partners LLC, a Cayman Islands limited liability company (the “Sponsor”). The registration statement for the Company’s Initial Public Offering was declared effective on March 11, 2026. On March 13, 2026, the Company consummated the Initial Public Offering of 23,000,000 units (the “Units”), which includes the full exercise by the underwriters of their over-allotment option of 3,000,000 Units, at $10.00 per Unit, generating gross proceeds of $230,000,000. Each Unit consists of one Class A ordinary share and one-third of one redeemable warrant (each “Public Warrant”, and collectively the “Public Warrants”). Each whole Public Warrant entitles the holder thereof to purchase one Class A ordinary share at a price of $11.50 per share, subject to adjustment.

Simultaneously with the closing of the Initial Public Offering, the Company consummated the sale of an aggregate of 5,066,666 Private Placement Warrants (each “Private Placement Warrant”, collectively the “Private Placement Warrants”) at a price of $1.50 per Private Placement Warrant, generating gross proceeds of $7,600,000. Of those 5,066,666 Private Placement Warrants, the Sponsor purchased 3,533,333 Private Placement Warrants, Cohen & Company Capital Markets, a division of Cohen & Company Securities, LLC (“Cohen” or the “Representative”) purchased 1,226,666 Private Placement Warrants, Jett Capital Advisors, LLC purchased 230,000 Private Placement Warrants and Sternship Advisers Pty Ltd purchased 76,667 Private Placement Warrants.

Transaction costs amounted to $14,481,900, consisting of $4,600,000 of cash underwriting fees, $9,200,000 of deferred underwriting fees, and $681,900 of other offering costs.

The Company’s management has broad discretion with respect to the specific application of the net proceeds of the Initial Public Offering and the sale of the Private Placement Warrants, although substantially all of the net proceeds are intended to be applied generally toward consummating a Business Combination. There is no assurance that the Company will be able to complete a Business Combination successfully. The Company must complete a Business Combination with one or more target businesses that together have an aggregate fair market value of at least 80% of the value of the Trust Account (as defined below) (excluding the deferred underwriting commissions and taxes paid or payable on the interest earned on the Trust Account) on the date of the execution of a definitive agreement into an initial Business Combination. The Company will only complete a Business Combination if the post-transaction company owns or acquires 50% or more of the outstanding voting securities of the target or otherwise acquires a controlling interest in the target sufficient for it not to be required to register as an investment company under the Investment Company Act of 1940, as amended (the “Investment Company Act”). Following the closing of the Initial Public Offering, on March 13, 2026, an amount of $230,000,000 ($10.00 per Unit) from the net proceeds of the sale of the Units and the Private Placement Warrants was placed in the trust account (the “Trust Account”), with U.S.-based trust account, Continental Stock Transfer & Trust Company, acting as trustee. The funds held in the Trust Account are invested, at the Company’s election, in (i) U.S. government treasury obligations with a maturity of 185 days or less, (ii) money market funds meeting certain conditions under Rule 2a-7 under the Investment Company Act, which invest only in direct U.S. government treasury obligations, or (iii) interest-bearing demand deposit accounts or cash held in deposit accounts, in each case until the earlier of (i) the completion of a Business Combination and (ii) the distribution of the funds held in the Trust Account, as described below.

The Company will provide its holders of the outstanding Public Shares (the “public shareholders”) with the opportunity to redeem all or a portion of their Public Shares upon the completion of a Business Combination either (i) in connection with a shareholder meeting called to approve the Business Combination or (ii) without a shareholder vote by means of a tender offer. The decision as to whether the Company will seek shareholder approval of a Business Combination or conduct a tender offer will be made by the Company, solely in its discretion, and will be based on a variety of factors such as the timing of the transaction and whether the terms of the transaction would require the Company to seek shareholder approval under applicable law or stock exchange listing requirements. The public shareholders will be entitled to redeem their Public Shares for a pro rata portion of the amount then in the Trust Account (initially anticipated to be $10.00 per Public Share, plus any pro rata interest earned on the funds held in the Trust Account and not previously released to the Company to pay its tax obligations and up to $100,000 of interest to pay liquidation expenses). There will be no redemption rights upon the completion of a Business Combination with respect to the Company’s warrants. The Public Shares subject to redemption will be recorded at redemption value and classified as temporary equity upon the completion of the Initial Public Offering in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 480, Distinguishing Liabilities from Equity (“ASC 480”).

The Company will proceed with a Business Combination only if the majority of the shares voted are voted in favor of the Business Combination. If a shareholder vote is not required by law and the Company does not decide to hold a shareholder vote for business or other reasons, the Company will, pursuant to its amended and restated memorandum and articles of association (the “Amended and Restated Memorandum and Articles of Association”), conduct the redemptions pursuant to the tender offer rules of the U.S. Securities and Exchange Commission (“SEC”) and file tender offer documents with the SEC prior to completing a Business Combination. If, however, shareholder approval of the transaction is required by law, or the Company decides to obtain shareholder approval for business or other reasons, the Company will offer to redeem shares in conjunction with a proxy solicitation pursuant to the proxy rules and not pursuant to the tender offer rules. If the Company seeks shareholder approval in connection with a Business Combination, the Sponsor has agreed to vote its Founder Shares (as defined in Note 5) and any Public Shares purchased during or after the Initial Public Offering in favor of approving a Business Combination. Additionally, each public shareholder may elect to redeem their Public Shares irrespective of whether they vote for or against the proposed transaction or do not vote at all.

Notwithstanding the above, if the Company seeks shareholder approval of a Business Combination and the Company does not conduct redemptions pursuant to the tender offer rules, the Amended and Restated Memorandum and Articles of Association provides that a public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”)), will be restricted from redeeming its shares with respect to more than an aggregate of 15% or more of the Public Shares, without the prior consent of the Company.

The Sponsor has agreed to waive redemption rights with respect to any Founder Shares (as defined in Note 5) held and any Public Shares they may acquire during or after the Initial Public Offering in connection with the completion of Business Combination, except that Public Shares held by the initial shareholder will be subject to mandatory redemption upon any diminution of the Trust Account in connection with an extension, and such shares will be entitled to redemption at a price equal to the per share redemption value then held in the Trust Account in connection therewith.

The Company will have until 24 months from the closing of the Initial Public Offering to complete a Business Combination (the “completion window”). However, if the Company anticipates that it may not be able to consummate a Business Combination within 24 months from the closing of the Initial Public Offering, the Company may, but is not obligated to, by resolution of the board if requested by the initial shareholder, extend the period of time to consummate a Business Combination the Company may seek shareholder approval to amend the amended and restated memorandum and articles of association to extend the date by which the Company must consummate the initial Business Combination. If the Company seeks shareholder approval for an extension, holders of Public Shares will be offered an opportunity to redeem their shares, regardless of whether they abstain, vote for, or against, the Company’s initial Business Combination, at a per share price, payable in cash, equal to the aggregate amount then on deposit in the Trust Account, including interest earned thereon (which interest shall be net of taxes paid or payable (excluding any 1% U.S. federal excise tax on stock repurchases under the Inflation Reduction Act of 2022, or similar tax, that is imposed on the Company, if any) and up to $100,000 of interest to pay liquidation expenses) and not previously released to the Company pursuant to permitted withdrawals, divided by the number of then issued and outstanding Public Shares, which redemption will completely extinguish Public Shareholders’ rights as shareholders (including the right to receive further liquidating distributions, if any), subject to applicable law. For the avoidance of doubt, the time to complete a Business Combination shall not be extended beyond 24 months without a shareholder vote. The underwriters have agreed to waive their rights to their deferred underwriting commission held in the Trust Account in the event the Company does not complete a Business Combination within the completion window and, in such event, such amounts will be included with the other funds held in the Trust Account that will be available to fund the redemption of the Public Shares.

In order to protect the amounts held in the Trust Account, the Sponsor has agreed that it will be liable to the Company if and to the extent any claims by a third party for services rendered or products sold to the Company, or a prospective target business with which the Company has entered into a written letter of intent, confidentiality or other similar agreement or Business Combination agreement (except for the Company’s independent registered public accounting firm), reduce the amount of funds in the Trust Account to below the lesser of (i) $10.00 per Public Share and (ii) the actual amount per Public Share held in the Trust Account as of the date of the liquidation of the Trust Account, if less than $10.00 per Public Share due to reductions in the value of the trust assets, less taxes paid or payable and up to $100,000 of interest to pay liquidation expenses, provided that such liability will not apply to any claims by a third party or prospective target business who executed a waiver of any and all rights to the monies held in the Trust Account (whether or not such waiver is enforceable) nor will it apply to any claims under the indemnity of the underwriters of the Initial Public Offering against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”).

Subsequent to March 31, 2026, the Company directed Continental Stock Transfer & Trust Company (“Continental”), as trustee, to reinvest the funds held in the Trust Account from an interest-bearing demand deposit account into U.S. government treasury obligations with a maturity of 185 days or less, in accordance with the investment options permitted under the Company’s Investment Management Trust Agreement with Continental, signed in connection with the Initial Public Offering (the “Trust Agreement”). This change does not affect the amount held in the Trust Account or the Company’s ability to complete a Business Combination within the completion window.

Liquidity, Capital Resources and Going Concern

The Company’s liquidity needs up to June 30, 2026 had been satisfied through the loan under an unsecured promissory note from the Sponsor of up to $300,000 (the “Promissory Note”) (see Note 5) and the proceeds from the sale of Private Placement Warrants in a private placement to the Sponsor, Cohen & Company Capital Markets, Jett Capital Advisors, LLC and Sternship Advisers Pty Ltd. At June 30, 2026, the Company had cash of $1,889,425 and a working capital surplus of $1,784,775.

In connection with the Company’s assessment of going concern in accordance with FASB ASC 205-40, Presentation of Financial Statements - Going Concern, the Company does not believe it will need to raise additional funds in order to meet the expenditures required to operate its business. However, if the estimate of the costs of identifying a target business, undertaking in-depth due diligence and negotiating a Business Combination are less than the actual amount necessary to do so, the Company may have insufficient funds available to operate its business prior to the Initial Business Combination. Management has determined that upon the consummation of the Initial Public Offering and the sale of the Private Placement Warrants, the Company has sufficient funds to finance the working capital needs of the Company within one year from the date of issuance of the financial statements.