Recently, Mexico's Tax Administration Service (SAT) announced a major adjustment. The mandatory requirement for electronic declaration transmission, originally scheduled to take effect at the end of this year, has been postponed to April 1, 2026. This gives enterprises engaged in import and export business with Mexico nearly four more months for preparation and adaptation. According to the latest notice from SAT, this key measure under the foreign trade digitalization reform has had its mandatory implementation date moved from December 9, 2025 to April 1, 2026. Authorities stated that the postponement is mainly to allow all relevant enterprises ample time to adapt to the new digital customs declaration system, ensuring a smooth and orderly transition of the entire customs clearance process.

During the transition period ending on March 31, 2026, importers will retain certain flexibility when declaring the value of goods. Enterprises may continue to complete customs clearance via traditional paper-based procedures, or proactively submit the Electronic Customs Declaration (MVE) through the Single Foreign Trade Window (VUCEM) system in advance. This serves as a valuable buffer zone, allowing companies to arrange digital transformation plans reasonably based on their own IT development progress. What exactly is the much-discussed Electronic Customs Declaration (MVE)? It is far more than a simple electronic form. In essence, MVE is a mandatory fiscal and customs document designed to strengthen tax inspections and curb fraud in import and export activities. Importers are required to declare the full actual value of goods, including commodity prices, freight, insurance premiums and all other associated costs. This document acts as the official basis for calculating value-added tax and customs duties. More importantly, by linking declared values directly to the tax system, it functions as a core tool to prevent underreporting of goods value and various fraudulent practices. Regarding the postponement, the Director General of Mexico's General Administration of Foreign Trade Audits (AGACE) explained that the move not only grants enterprises extra preparation time, but also enables the Tax Administration Service (SAT) to further optimize internal workflows, enhance policy transparency, and minimize unnecessary audit disputes caused by inadequate preparation in the future. He added that the postponement aims to streamline overall compliance procedures and advance the shift from paper documents to digital formats. The authorities also clarified that during the transition period, enterprises that have fully deployed the MVE system may voluntarily revise their declaration information without incurring financial penalties. This penalty exemption policy has won wide recognition across the industry. Margarita Cavazos, Vice President of the Mexican Metropolitan Customs Brokers Association, regarded it as a very positive signal. She stated that it creates a rare safe window for businesses. Companies can conduct system integration tests, sort out historical data and provide operational training for staff without worrying about compliance risks arising from errors during the commissioning phase.

Nevertheless, traditional paper-based declarations will be completely phased out on April 1, 2026, marking the full arrival of an era of mandatory digital compliance for Mexican customs. Therefore, this four-month extension is undoubtedly the final golden preparation period for enterprises. Relevant companies must make the most of this window and leverage the official penalty exemption policy to complete the final system testing and debugging. This will ensure smooth and efficient customs declarations when the new rules take full effect, and prevent any disruptions to business operations.