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Altiplano Metals Inc.

250 Southridge NW, Suite 300

Edmonton, AB

Canada

T6H 4M9

Altiplano Updates Status on Late Filing of Financial Statements

EDMONTON AB, September 15, 2026 - Altiplano Metals Inc. (TSXV: APN) (WKN: A2JNFG) ("Altiplano" or the "Company") continues to work towards the filing of its annual financial statements for the year ended March 31, 2026, management's discussion and analysis, and the related CEO and CFO certifications (collectively, the "Required Filings").

The Company and its auditor continue to work through the remaining audit procedures, with audit manager review underway this week. Partner and engagement quality control review remain planned for the week of September 21, 2026. Certain key third-party confirmations remain outstanding and are required to complete the remaining audit procedures. The Company is working to have these confirmations returned this week.

Provided the outstanding confirmations are received this week and the remaining audit procedures and reviews are completed without unforeseen delays, the Company expects to maintain its previously announced timeline to file the Required Filings by September 28, 2026. The Company continues to expect to file its interim first-quarter financial statements within one week thereafter.

The Required Filings were due to be filed by July 29, 2026. In connection with the anticipated delays in making the Required Filings, the Company made an application for a Management Cease Trade Order ("MCTO") under National Policy 12-203 Management Cease Trade Orders ("NP 12-203") to the Alberta Securities Commission, as principal regulator for the Company, and the MCTO was issued on July 31, 2026. The MCTO restricts all trading by the Company's CEO and CFO in securities of the Company, whether direct or indirect. The issuance of the MCTO will not affect the ability of persons who are not directors, officers or insiders of the Company to trade their securities. MCTO will remain in effect until it is revoked or varied.

The Company confirms that it intends to satisfy the provisions of the alternative information guidelines described in NP 12-203 by issuing bi-weekly default status reports in the form of a news release until it meets the Required Filings requirement. The Company has not taken any steps towards any insolvency proceeding and the Company has no material information relating to its affairs that has not been generally disclosed.

For additional information on the MCTO, please refer to the Company's news releases dated July 21, 2026, August 4, 2026, August 18, 2026 and September 1, 2026, available for viewing on the Company's profile on SEDAR+.

ON BEHALF OF THE BOARD

Alastair McIntyre,

Director and CEO

E: alastairm@apnmetals.com

T: (416) 434 3799

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Forward-Looking Information: This news release contains forward-looking information within the meaning of applicable Canadian securities laws, including statements regarding the Company's application for a management cease trade order, the commencement and completion of the audit, the anticipated timing for filing the Required Filings, and the filing of its interim first-quarter financial statements. Forward-looking information is based on assumptions and is subject to known and unknown risks and uncertainties that could cause actual results to differ materially from those expressed or implied, including the risk that the audit may not commence or be completed as anticipated, the Required Filings may not be filed within the expected timeframe, the interim first-quarter financial statements may be delayed, or the management cease trade order may not be granted. Readers are cautioned not to place undue reliance on forward-looking information. The Company undertakes no obligation to update or revise such information except as required by applicable securities laws.