Mexico's Customs Reform Would Drop the 50 Percent Seizure Gap

On September 22, Héctor Alonso Romero Gutiérrez, head of Mexico's national customs agency, ANAM, appeared before the Chamber of Deputies' Comisión de Hacienda to explain a reform to the Ley Aduanera. The Chamber's own bulletin puts the purpose of the new audits in one line: "El objetivo de las revisiones de oficio es quitar la discrecionalidad".

Mexico's customs law reform was filed on September 8 alongside the 2027 economic package, as a separate decree, Anexo F of that day's Gaceta Parlamentaria. Its changes to five articles would let customs hold a shipment at the border over any gap between your declared value and the transaction value of identical or similar goods, and would put a cash price on getting it back.

If your Mexican entity imports components from its parent at intercompany prices, or buys Asian inputs below what other importers declare for the same goods, this is the part of the package that reaches your freight. As filed, the reform takes effect the day after it is published.

What Mexico's customs law reform changes at the border

Today, Article 151, fraction VII allows a precautionary seizure only when the declared value is "inferior en un 50% o más al valor de transacción de mercancías idénticas o similares," and never where the importer posted the estimated-price guarantee of Article 86-A.

The initiative keeps only the comparison: a value "inferior al valor de transacción de mercancías idénticas o similares" is enough. A new second paragraph in Article 144, fraction XII turns the same comparison into an audit trigger, under which "las autoridades aduaneras iniciarán de oficio el ejercicio de las facultades de comprobación." The text sets no minimum gap.

The Executive's case is 2,541 import operations in 2025 and the first eight months of 2026, worth 1,586.7 million pesos, that did not trigger a seizure, mainly because they sat below the 50 percent line.

Dropping the Article 86-A exception reaches the estimated-price channel. Figures in the exposición de motivos put it at 753 importers, 44,232 definitive import operations and 13,622 million pesos guaranteed in 2025, in footwear, textiles and apparel. A resolution published September 14 revoked the price list's textile and apparel annex.

The cash deposit that releases a seized shipment

For goods outside Hacienda's estimated-price list, the proposed Article 154 would give you ten business days from notice of the proceeding to ask for your goods back against a deposit, in two tiers. Below a 20 percent gap, you may replace the seizure with a cash deposit or a deposit in the cuentas aduaneras de garantía. At 20 percent or more, the text offers only "un depósito en efectivo."

In both tiers the amount equals the contribuciones and countervailing duties the value difference would generate. Under Article 2 of the Código Fiscal, contribuciones take in every federal tax, so on the plain text the deposit covers import VAT on the difference as well. Goods still on the estimated-price list, such as footwear, get no specific substitution rule, and the initiative is silent on whether the Código Fiscal guarantees in the unchanged first paragraph apply.

If you prove the value, the amended Article 153 would return the goods and release the guarantee or refund the cash. The four-month limit for a final resolution stays as it is.

The committee heard what the interval costs. Gabriel Padilla, who heads the INA, the national auto parts industry body, described a shipment held about six months after the company paid the assessment: "Seis meses no representan solamente un problema administrativo, pueden significar paros de producción." A trade specialist cited in the same report put the carrying cost at 4,000 to 14,000 pesos a day per unit held.

If another company is the importer of record for your goods, ask who posts that deposit and what your contract says about valuation risk. None of the reform's sources address that allocation, and it belongs in the structure decision.

IMMEX temporary imports and the 20 percent presumption

Article 177, fraction XII presumes an infraction when goods entered under a regime that lets duties be determined without payment are undervalued against identical or similar goods, and the initiative lowers that gap from 50 percent to 20 percent. TaxToday lists temporary import among those regimes, and the fine under Article 178, fraction XI is 130 to 150 percent of the omitted foreign-trade taxes.

The exposición de motivos keeps a second condition, that on a definitive import "se hubiera omitido el pago total o parcial de los impuestos al comercio exterior." Article 51 defines those taxes as the general import and export duties, so import VAT does not count.

The presumption therefore lands on dutiable non-originating inputs, above all goods from countries without a trade agreement that fall under Mexico's increase on 1,463 tariff lines.

Countervailing duties on such an input add to the omitted amount, though the text does not say whether one alone, on a 0 percent input, is enough. It is also silent on whether a USMCA, PROSEC or Regla Octava rate counts in that calculation.

Seizure and de oficio audits carry no duty condition and no regime limit, so a duty-free input priced below its comparables can still be seized and audited.

ANAM's press release says "la iniciativa no modifica los regímenes de importación temporal," and INDEX's Fernanda Padilla Rangel "pidió precisar expresamente el tratamiento de las importaciones temporales de empresas IMMEX." Any answer on IMMEX temporary imports would come in the committee's report.

Customs valuation and your transfer price

Under Article 72, identical goods are those "producidas en el mismo país que las mercancías objeto de valoración" and sold for export to Mexico. Article 73 applies the same test to similar goods, and where several values exist, "se utilizará el valor de transacción más bajo."

The initiative does not mention related parties or transfer pricing, and your defences for an intercompany price sit in the existing law. Article 70 accepts a related-party price that "se aproxima mucho a alguno de los valores criterio," such as the value of identical or similar goods sold to unrelated importers, when the pedimento declares the relationship and states that it did not influence the price. Article 69 offers a second route.

No source yet says whether ANAM will accept a transfer-pricing study or an advance pricing agreement as that proof. ANPACT's Alejandra Rosete told the committee that "los importadores no tienen acceso a los valores de mercancías idénticas o similares," and Romero Gutiérrez said the rules of ANAM's Sistema de Inteligencia de Valor would be public, so that anyone applying the same rules "va a poder replicar los resultados."

When Mexico's 2027 customs law reform takes effect

The initiative's single transitory article says the decree "entrará en vigor al día siguiente de su publicación" in the Diario Oficial. As filed, it carries no January 1 date, no phase-in and no IMMEX carve-out.

The budget law's deadlines, "a más tardar el 20 de octubre" in the Chamber and October 31 in the Senate, bind the Ley de Ingresos alone. El Economista reported on September 22 that the customs reform was expected to clear the committee that week and reach the floor the week after. The Gaceta Parlamentaria of September 25 carried no committee report on it. El Economista's September 14 report had the Chamber approving the Ley de Ingresos and its package on October 14 and 15.

Last year's customs initiative carried the same day-after clause until the Senate set January 1, 2026, and the decree was published on November 19, 2025, about four weeks after Congress finished. If this year's clause survives and a similar lag follows an October 31 finish, the rules would reach shipments from late November 2026.

The committee's chair, Carol Antonio Altamirano, wants evidence that the measures already approved "han producido resultados concretos." CAAAREM, the customs brokers' confederation, asked to keep intermediate goods and fixed assets out of the rule, and Concanaco proposed "una regla de materialidad de 20%" under which, below a 20 percent gap, goods keep clearing while customs reviews them and may ask for a proportional guarantee.

The electronic value declaration starts October 1

On September 22, the DOF published the Segunda Resolución de Modificaciones a las RGCE 2026, in force September 23, on the value declaration we covered in August. As that resolution rewrites it, Transitorio Décimo Primero of the RGCE 2026 keeps the legacy compliance method only "hasta el 30 de septiembre de 2026."

The resolution extends two facilities to December 31, 2026: relief from transmitting the Reglamento's Article 81, fraction II to IV documents when they travel under Article 36-A, and the option to file form E15, a sworn summary of contracts, in place of the contracts.

OEA-certified companies are exempt on operations under their registration unless customs asks. IMMEX temporary imports under Article 108 are not on the exemption list.

In Expansión's account, Romero Gutiérrez said the MVE obligation "se complementa con la propuesta de reforma a la Ley Aduanera," and before the committee he described the de oficio reviews as running on "toda la información que deben entregar los informadores y la que ya se tiene."

What to settle before the committee votes

If you do not hold OEA certification, confirm with your broker before September 30 that E2 filings are going through from October 1 on every pedimento that needs one, and list the contracts you will summarize on E15 until December 31.

Build the valuation file for your top imported part numbers while the committee writes its report. The file ties the intercompany price to an Article 70 test value, confirms that the pedimento declares the relationship, and sets out the physical characteristics, quality and brand that Article 72 uses to decide whether a lower-priced good is identical.

Then run two numbers: which temporary-import inputs would owe duty on a definitive import, and what deposit the value gap on your most exposed inputs would require if a shipment were held.

The bottom line

The reform would ask every pedimento one question at the border: whether the declared value sits at or above what the same goods from the same country have been declared at.

If you import from a related party, your proof already has its form in Articles 69 and 70. Under the text as filed, assembling it after a seizure means doing so with a shipment held at a daily carrying cost or released against a deposit.

If you are still choosing how to enter Mexico, the choice of importer of record carries a cash figure under this initiative. If you already operate here, the valuation file you build this autumn serves under whichever version of the text Congress passes.

Calder & Vale advises Canadian and US companies entering and operating in Mexico on entity structure, on site and incentives through direct relationships with the state economic development ministries, and on customs valuation and IMMEX exposure.