A guide for U.S. companies that sell into Mexico, especially to their own subsidiary or to a related distributor. The short answer: on October 23, 2026 Mexico's Official Gazette published a reform to the Customs Law that takes effect January 1, 2027. From that date, if the value declared on the pedimento is below the transaction value of identical or similar goods, customs may audit the operation on its own initiative and seize the goods at the border. A low price is not illegal; what changes is that it has to be proven with documents, on short deadlines.
What changes and on what basis
- Audit for low value (article 144, section XII): when the declared value is below the transaction value of identical or similar goods (articles 72 and 73), the authority may open an audit on its own initiative.
- Precautionary seizure (article 151, section VII): the same situation becomes a ground for seizing the goods, in the cases and under the procedure that the rules due by December 31, 2026 will set.
- Replacing the seizure (article 154): the importer has ten business days to substitute it. If the value gap is under 20%, with a cash deposit or a customs guarantee account; if it is 20% or more, with a cash deposit only.
- If the value is proven (article 153): when the company shows the value was determined under the Law, the ruling carries no penalty and the goods or the guarantee are returned.
- Temporary imports and IMMEX (article 177, section XII): declaring a value 20% or more below that of identical or similar goods counts as smuggling when, had the goods been imported definitively, duties or antidumping duties would have been omitted.
- Hydrocarbons and petroleum products (article 185): several fines rise to a range of 50% to 100% of the commercial value of the goods.
Who is most exposed
The reform compares the declared value with that of identical or similar goods. The operations that stand out are the ones priced away from the market for a legitimate reason that is poorly documented in the customs file:
- Related-party sales: the U.S. parent selling to its Mexican subsidiary at an intercompany price. The transfer-pricing study exists for income tax; customs will ask that the same price hold up as customs value.
- IMMEX plants: inputs and machinery entering temporarily at internal values. Here the 20% line separates an adjustment from a crime.
- Discounts, close-outs and second-quality goods: real prices below the usual level, with no support for the discount in the file.
- Exclusive or volume distributors: prices agreed in framework contracts that nobody attaches to the entry.
What the company must be able to show
The primary valuation method is still transaction value: the price paid or payable, plus the items the Law adds when they are not on the invoice (freight and insurance to the border, commissions, packaging, royalties, goods and services supplied to the seller). Between related parties the company must also be able to show that the relationship did not influence the price. The documents that prove it are the usual ones: a complete invoice, the contract or purchase order, proof of payment, support for any discount and, between related parties, the transfer-pricing study or an explanation of the pricing method. The electronic value declaration and the COVE must match all of it. What is new is not the list; it is that from January it is requested the same day the truck is held.
What the U.S. team usually asks
- Does our transfer-pricing study cover us? It helps, but it is not the same thing. The study justifies the price for income tax in both countries; customs applies the valuation methods of the Customs Law and compares against identical or similar goods. The two should be reviewed together before January.
- Who is liable if the goods are seized? The importer of record in Mexico, normally the subsidiary or the distributor. If the subsidiary has nobody to handle the procedure within ten business days, the problem moves up to the parent.
- Does it reach what already crossed? The new seizure grounds apply from January 1, 2027. Audit powers over past operations follow the general rules and their limitation periods.
- And if the low price is legitimate? The goods or the guarantee are released without penalty, provided it is proven within the procedure. The real cost is the days the truck is held and the cash deposit in the meantime.
Frequently asked questions
When does the reform apply?
From January 1, 2027. The decree was published in the Official Gazette on October 23, 2026, and the rules on value-based precautionary seizure are due by December 31, 2026.
Is a low intercompany price illegal?
No. The Law accepts transaction value between related parties when the relationship did not influence the price. What changes is that, if that value is below identical or similar goods, customs may audit and seize, and the company must prove the price with documents within the procedure.
What is the difference between under 20% and 20% or more?
To replace the seizure: under a 20% gap, a cash deposit or a customs guarantee account is accepted; at 20% or more, cash deposit only. In temporary imports, a gap of 20% or more can amount to smuggling.
What should be done before January?
Identify the operations priced below market and the reason for each, gather the support for that reason before customs asks, and decide who handles the procedure in Mexico if a seizure arrives. Each company has a different order depending on volume, program and pricing structure.
General information, updated October 2026. It does not replace legal advice for a specific case.
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