Mexico Constitutionalises Its Mining Reform — and Draws a Line at 'Acquired Rights'
In June 2025 Mexico's Supreme Court upheld the 2023 mining and water reforms, ruling that a future concession extension is a legal expectation, not a vested right. Paired with a freeze on new concessions and a heavier fiscal take, it settles the question for running mines — and narrows the runway for new ground.
What happened
In June 2025 the First Chamber of Mexico's Supreme Court (SCJN), resolving Amparo en Revisión 391/2024, upheld the constitutionality of the May-2023 reforms to the Mining Law, the National Water Law and related statutes. The reforms shortened new concessions to 30 years, tightened the link between mining and water rights, and required social-impact assessment and environmental authorisation ahead of activity.
The reasoning is the part every general counsel should read. The Court held that the reforms do not retroactively impair 'acquired rights': a right to a future concession extension, or to preferential water access, is a mere legal expectation, not a vested right. Days earlier, President Sheinbaum confirmed the administration will grant no new mining concessions through the end of its term in 2030. Layered on top is a heavier fiscal take — the special mining duty raised to 8.5% of EBITDA and the extraordinary precious-metals royalty doubled to 1.0% of revenue.
Why it matters for dispute formation
The ruling is a shield — but a narrow one. Running mines with existing title and prior approvals are protected; the growth that depends on new ground, renewals or fresh water permits is not. That line converts the value question into a documentary one: what, exactly, was granted, and does today's activity rest on it?
For operators, the work is custodial rather than confrontational — preserving the concession-and-approval chain, modelling the higher royalties across price scenarios, and anchoring every new authorisation to pre-existing rights. The constitutional challenge to the regime is now spent; the disputes that remain are about the edges of what 'acquired' covers, and they will be won or lost on the record.
Who's exposed
Runs the Mulatos district and the Puerto Del Aire development in Sonora under existing, grandfathered concession rights — precisely the category the Court's 'acquired rights' reasoning protects. Its exposure is the higher fiscal take and the permitting path for new activity, not its producing title.
Operates the Cozamin copper-silver mine in Zacatecas inside the same perimeter; its live questions are a long-running royalty dispute and a reported divestment process, both playing out against a settled, more statist regime.
Ramping Terronera and running Guanaceví where new concessions are frozen and water-mining linkage is tightened — growth now turns on demonstrating that authorisations rest on pre-existing title and prior approvals.
The historical parallel · Legacy Vulcan (Calica) v. Mexico (ICSID ARB/19/1)
The domestic 'acquired rights' line has an international shadow. After Mexico revoked Calica's port concession and halted its Quintana Roo quarrying, Vulcan took the dispute to ICSID, claiming more than US$1.5 billion — still unresolved and now in settlement talks. The lesson cuts both ways: running rights are defended first in Mexican courts and, if impaired, in treaty tribunals — and in either forum the record of what was actually granted decides it.
What to watch
- How SEMARNAT's environmental-authorisation practice treats incremental activity at existing districts under the concession freeze.
- Whether the 'acquired rights' reasoning is tested at renewal, when a 30-year term actually lapses.
- The marginal state take at elevated gold and silver prices, as the profit-geared royalties bite.
- Any move from freezing new concessions to recovering unused ones.
Sources
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Get the Intelligence BriefFor general information only; not legal advice, and no attorney–client relationship is formed through this article. Company names appear because the operators are exposed to a public development — not as a statement of wrongdoing or a predicted outcome. Figures are as reported by the linked sources.