On November 19, 2025, the “Decree amending, adding and repealing various provisions of the Customs Law” (hereinafter the “Decree”) was published in the Federal Official Gazette. This amendment (the “Amendment”) to the Mexican Customs Law (the “Law”) represents an important change in the approach to customs audit monitoring, incorporating a model of preventive controls and technological traceability in foreign trade operations, accompanied by a greater documentary burden for importers, as well as a significant reinforcement of customs sanctions.
It is important to note that such Decree will enter into effect on January 1, 2026, except for certain exceptions provided for in the transitional articles.
Among the most relevant aspects of the Amendment are those related to technological infrastructure in bonded warehouses and strategic bonded warehouses; the evidence of the origin of goods for the application of tariff preferences under Mexico’s international treaties; strengthening the responsibility of both customs brokers and importers; expanding the information that must be included in the electronic foreign trade file; and increasing the fines associated with violations related to the importation and exportation of goods.
• Responsibilities of the importer and customs brokers
The importer remains directly responsible for the payment of import duties and complying with any applicable non-tariff regulations. The customs broker remains jointly and severally liable for the import duties and antidumping or countervailing duties arising from the customs manifests (pedimentos) in which the customs broker is involved; however, it is expressly stated that such joint and several liability does not extend to fines.
In addition, the scope of liability of the customs broker and the customs broker agency is expanded to expressly include responsibility for the correct determination of the payment of duties and the verification that the importer has all the documentation proving compliance with its obligations in terms of foreign trade and non-tariff regulations and restrictions, in addition to tariff classification and the Commercial Identification Number (NICO).
• Reinforcement of fines and sanctions
The Amendment significantly increases fines associated with violations related to the importation and exportation of goods, growing from a historical range of 70% to 100% of the commercial value of the goods to a new range of 250% to 300% of such commercial value.
The punitive trend is clear: minimal tolerance for formal errors, incomplete documentation, or undervaluation of foreign trade goods.
• Certification of origin for imported goods and documentation for tariff preferences
The Amendment incorporates the obligation for importers to attach additional documentation when goods that are eligible for tariff preferences transit through countries that are not a Party to the trade agreement in question, needing to prove that such goods were under customs control during such transit.
Likewise, when the importer determines weight, volume, or other characteristics using its own instruments, the importer must have calibration reports or certificates to support the data transmitted.
• Electronic file of transactions and documentation related to the transaction value
The Amendment substantially expands the content of the electronic foreign trade file. In addition to traditional documentation, importers must now include information and documents evidencing the financial resources used to carry out the commercial transaction.
A high-impact change in the Law is the express requirement for importers to have purchase agreements, commercial contracts, or documentary instruments proving the declared transaction value and its terms of sale.
This means that invoices and payment receipts related to incremental expenses are no longer considered sufficient to support the value of the imported goods; the file must reflect the contractual and financial relationship that gave rise to the price that was declared.
• Technological systems and operational traceability
Bonded warehouses and strategic bonded warehouses must have electronic systems that enable inventory control, video surveillance, security, traceability, and real-time monitoring, which are interoperable with the electronic Customs system and provide continuous remote access for the authorities.
This same technological standard will be required for those requesting the clearance of their goods through a Different Location other than the Authorized Location, which reinforces the transition from customs control to a model of preventive supervision based on continuous monitoring by the authorities.
• Tariff classification and commercial identification number consultations
It is clarified that tariff classification inquiries may be submitted by importers prior to the foreign trade operation they intend to carry out, not only when there is doubt between two or more customs tariff classifications (HS Codes), but also when the tariff classification of the goods and the Commercial Identification Number (NICO) are completely unknown.
• Rectification of customs manifests (pedimentos)
Data declared in the customs manifests (pedimentos) can be rectified before activating the customs automated selection system, except in cases where authorization from Mexican Customs is required.
• Subsequent application of tariff preferences
Importers can request the application of preferential tariff treatment after importation, provided that the origin of the goods is evidenced in accordance with the applicable trade agreement and within the time limits established therein.
• Documentary traceability of the production process applicable in customs transfers
The obligation to request, provide, and retain the documentation required under Article 59, Section V of the Law (information and documents evidencing the financial resources used to carry out the foreign trade operation) is added, starting as from the temporary importation of the goods and until their transfer, including technical and accounting information that evidence the production process to which such transferred goods were subjected.
• Waybill Supplement (Complemento Carta Porte) mandatory for goods in transit
The transportation services electronic tax invoice (CFDI) must include a Waybill supplement (Complemento Carta Porte) when the goods are in transit, in order to evidence the legality of the transportation of the goods.
• Reduced term for regularization of goods after the cancellation of the IMMEX program
Once notification of the cancellation of the IMMEX Program has been notified, the company will have a maximum period of sixty (60) calendar days to either return abroad or change to the definitive import regime those goods temporarily imported under their IMMEX Program.
• New requirements for Certified Company registration
Two factors are added that prevent a company from obtaining or maintaining registration as a Certified Company: if any of the shareholders of the company has been convicted of crimes that result in imprisonment, and if the company is subject to administrative sanctions related to the importation or exportation of goods.
• Term for issuing the new Regulations of the Mexican Customs Law
The Amendment to the Regulations of the Customs Law shall be published no later than May 1, 2026.
In conclusion, given the complexity of the new customs controls and their effect on foreign trade operations, we recommend importing companies to review with their foreign trade legal advisors how this Reform will impact them and what operational adjustments shall be implemented in order to prevent any type of sanctions by the Mexican customs authorities. The objective is to anticipate possible contingencies and ensure that foreign trade operations continue to develop without setbacks under the new legal framework.
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We hope you find this information useful. Should you have any questions or require further clarification regarding any aspect of these amendments to the Mexican Customs Law, please do not hesitate to contact a member of our Foreign Trade and Customs Practice Group.
