Customs law reformed again: undervalued goods and fuels
Published 23 October 2026 · Diario Oficial de la Federación
What changed
A new reform of the Ley Aduanera, the second in under a year, lets customs seize goods when the declared value is lower than the transaction value of identical or similar goods, and obliges it to open an audit in that case. An importer can replace the seizure with a deposit if it asks within ten business days (cash or a customs guarantee account when the shortfall is under 20 percent, cash only at 20 percent or more), and customs must resolve within four months of the file being complete. Certain infractions involving hydrocarbons and fuels carry a fine of 50 to 100 percent of their commercial value. It takes effect on 1 January 2027; its implementing rules are due by 31 December 2026.
Who it affects
All industries. Product types on our rules page: all fifteen.
The source and its dates
Diario Oficial de la Federación, via SIDOF (Secretaría de Gobernación), evening edition. Published 23 October 2026; enters into force on 1 January 2027 (implementing rules due by 31 December 2026). Checked against the source on 11 October 2026.
What to do
Check that the value on every pedimento is what you actually paid and can stand next to the prices of identical or similar goods: from 1 January 2027 a low value is grounds for seizure. Keep invoices, proof of payment and contracts in the file, and remember that a deposit requested within ten business days can release the goods.
Your customs broker, accountant or lawyer files and signs; this page sets out the rule and its source. Need it for your own case? Write to us.