Starting January 1, 2027, an importer into Mexico should declare a customs value it can support against the transaction value of identical or similar goods, and keep the valuation file ready to show it, because Mexican customs must open a review whenever the value on a pedimento falls below that benchmark. The rule comes from a decree amending the Ley Aduanera, published in the evening edition of the Diario Oficial de la Federación on October 23, 2026.
For U.S. shippers and brokers, the practical point is that the commercial invoice value on southbound freight gets a defined check at Mexican customs from January, and the importer's paperwork is what passes it.
What should importers declare and document?
- Declare a value you can support. If the commercial invoice price on a southbound load is below what identical or similar goods sell for, the importer should be able to show why under the valuation rules.
- Keep the valuation file ready. The Manifestación de Valor and its supporting documents are what the importer uses to prove the value in the administrative procedure (PAMA). If they show the value follows the valuation rules, article 153 has the case resolved immediately with no penalties.
- Agree who funds a deposit. Under article 154 the importer can replace a precautionary measure with a deposit within ten business days, and a cash deposit is the only option when the gap is 20 percent or more. Decide in advance who pays it and how fast.
- Ask your agente aduanal in December whether the supporting rules are out and which products they list.
What does the decree change?
The decree amends articles 151, 153, 154 and 177 and adds text to articles 144 and 185 of the Ley Aduanera. The pieces that matter for freight:
- Mandatory review (art. 144, section XII). When the declared value is below the transaction value of identical or similar goods under articles 72 and 73, customs authorities "iniciarán de oficio" their verification powers.
- Article 151, section VII. The same condition, "cuando el valor declarado en el pedimento sea inferior al valor de transacción de mercancías idénticas o similares," is listed as a ground for precautionary seizure (embargo precautorio) of the goods, for products the customs authorities list by rule. The previous text required the gap to be 50 percent or more and exempted importers who had posted a guarantee under article 86-A; both conditions are gone.
- Presumed infraction (art. 177, section XII). For goods under a regime that allows duties to be determined without payment, such as temporary imports and bonded warehouses, declaring a value "inferior en un 20% o más" than identical or similar goods is presumed to be an infraction when found in an audit, if duties would have been underpaid had the goods been imported definitively. The prior threshold was 50 percent.
- Hydrocarbons (art. 185, sections I to III). For hydrocarbons and petroleum products, the fines for the document and filing infractions in those sections are 50 to 100 percent of the commercial value of the goods.
How does the article 154 deposit procedure work?
Article 154 sets a replacement procedure for goods that are not subject to estimated prices set by the Secretaría de Hacienda. Within ten business days of being notified that the administrative procedure (PAMA) has started, the importer can ask to replace the precautionary measure with a deposit:
| Declared value is below identical or similar goods by | Deposit accepted |
|---|---|
| Less than 20 percent | Cash deposit, or a deposit in a customs guarantee account, for the duties and countervailing duties on the difference |
| 20 percent or more | Cash deposit only, for the same amount |
Under article 153, if the importer proves in the PAMA that the value was determined correctly under the valuation rules, the authority must resolve the case immediately with no penalties, release the goods and return the guarantee or deposit. Otherwise it must issue a final ruling within four months of the file being complete. If it misses that deadline, the actions that started the procedure lose effect.
What is still to come before January?
The decree's second transitory article says the article 151 rule applies to the goods and procedures set out in rules issued by the customs authorities, and that for other goods those authorities may set by rule the percentage gap that applies. Those rules must be published in the DOF no later than December 31, 2026. Until they appear, it is not clear which products article 151 covers or what gap will apply to the rest.
Posting Mexico freight? Brokers can post loads and get Mexico rates, carriers can find loads, and shippers can see rates for Mexico lanes at cargado.com.
Frequently asked questions
When does the customs valuation rule take effect?
January 1, 2027. The decree was published in the Diario Oficial de la Federación on October 23, 2026 (evening edition) and its first transitory article sets the start date.
Is there a minimum percentage gap before the rule applies?
No percentage is written into article 144, section XII or article 151, section VII; any declared value below the transaction value of identical or similar goods qualifies. The second transitory article lets customs authorities set a percentage by rule for goods not on their list, with rules due in the DOF by December 31, 2026.
What happens if customs questions the declared value?
A review opens under article 144, section XII. For goods on the customs authorities' list, article 151, section VII can also apply, and article 154 lets the importer ask, within ten business days of the PAMA notice, to replace that measure with a deposit: cash or a customs guarantee account if the gap is under 20 percent, cash only if it is 20 percent or more. The deposit then stands in place of the goods while the PAMA runs.
How long does customs have to decide?
Four months from the day after the file is complete, under article 153. If the authority misses it, the actions that opened the procedure lose effect. If the importer proves the value was correct, the case is resolved immediately with no penalties.
Does a guarantee under article 86-A still exempt an importer from article 151, section VII?
No. The previous article 151, section VII exempted importers who had posted that guarantee, and the decree removed the exception.
Sources
- Diario Oficial de la Federación, Oct 23, 2026 (edición vespertina): Decreto por el que se reforman y adicionan diversas disposiciones de la Ley Aduanera (SIDOF nota 5802077)
- Full decree text (SIDOF docFuente)
- ANAM: Reforman y adicionan diversas disposiciones de la Ley Aduanera
- Ley Aduanera, consolidated text before the decree (Cámara de Diputados, última reforma DOF 19-11-2025): prior arts. 151 VII (50 percent or more, art. 86-A exception) and 177 XII (50 percent or more)
- TLC Asociados: Claves del nuevo esquema fiscal aduanero, sustitución de embargos y presunción de infracciones
