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Update, September 21, 2026. The coexistence period described below was extended after this article was published. Under the Transitorio Décimo Primero of the RGCE 2026, as reformed by the Second Resolution of Amendments, importers may comply under the prior scheme through September 30, 2026, and two further facilities run through December 31, 2026. The checklist that follows still applies in full. The date it counts down to is now September 30.
On September 30, 2026, the transition window for the Manifestación de Valor Electrónica (MVE) closes. From October 1, anyone introducing goods into Mexico must transmit the value declaration electronically through the Ventanilla Única de Comercio Exterior (VUCEM, now operating for these filings as the VUTCE). The paper coexistence that importers have leaned on all year ends with the month.
This date has moved before. The obligation was first set for the start of the year, pushed to April 1, then to June 1 by SAT (Comunicado 23/2026), then to July 31, and now to September 30, through successive anticipated versions of the Segunda Resolución de Modificaciones a las Reglas Generales de Comercio Exterior 2026 released on the SAT portal. Each extension bought preparation time. This one is the last stretch of that runway. We have filed value declarations across more than 190,000 customs operations a year, at a 99.8% accuracy rate, over 122+ years and 39+ ports. What we tell every operation in the final stretch is the same: the risk is not the software. The risk is the value file behind it.
Because the electronic MVE is not a format swap. It is a per-invoice, on-the-record account of how you built the customs value of your goods and which documents prove it. The clock that matters is not the one counting down to October 1. It is the one measuring how ready your documentation is for the day the transition scheme is gone.
What changes for the MVE on October 1, 2026
Until September 30, two paths coexist. You can transmit the electronic E2 format through VUCEM, or you can continue under the traditional transitional scheme carried over from the Reglas Generales de Comercio Exterior 2025. During this window, the absence of an electronic transmission is not, by itself, a breach, provided you file and keep the value declaration and its supporting documents under the transitional regime.
From October 1, that optionality is gone. Under Article 59, fracción III of the Ley Aduanera and Regla 1.5.1 of the RGCE 2026, whoever introduces goods into national territory must transmit the MVE electronically. The deadline itself lives in the Transitorio Décimo Primero of the RGCE 2026, which the Segunda Resolución has now reformed to read September 30, 2026. The obligation reaches importers, agencias aduanales, and logistics operators alike. There is no separate calendar for small operations.
Two operational rules are easy to miss. First, the MVE is filed per operation, invoice by invoice, before the customs contributions are paid, not as a periodic filing. Second, for consolidated pedimentos, the transmission happens at closing, not per remesa. If your team still thinks of the value manifest as a document you attach once and forget, that mental model expires with the transition window.
Why the electronic MVE is a sworn value declaration, invoice by invoice
The reason this matters beyond the filing screen is what the MVE now represents. It is the importer declaring, factura by factura, how customs value was determined and which records support that determination. It ties your fiscal documents, your CFDI and XML, your commercial invoices, and your pedimento into one consistent account that the authority can read and cross-check.
That account did not get lighter under the 2026 reform. It got heavier. The reform of the Reglamento de la Ley Aduanera, published in the DOF on February 23, 2026, now requires the documents under its Article 81 to be preserved as part of the manifestación de valor. The value file is no longer a courtesy annex. It is the evidentiary spine of the import, and under the digital scheme it is legible to the authority in a way a paper folder never was.
The operational read is direct. When the transmission is electronic and structured, an inconsistency between what you declared and what your documents show does not sit quietly in a binder. It surfaces. That is precisely what a gabinete review, a procedimiento administrativo en materia aduanera, or a value challenge is built to find.
MVE readiness checklist: what to finish before September 30
Here is the final-stretch work, in the order it pays to do it.
1️⃣ Test the MVE in VUCEM now, with a live filing. Generate a manifestación in the window, capture the folio it issues, and declare that folio as an e-document on the pedimento. A login, profile, or e.firma problem discovered on October 1 is a held shipment. The same problem discovered this week is a support ticket.
2️⃣ Build the value file invoice by invoice. For each invoice, document how customs value was determined and prove every incrementable: freight, insurance, commissions, packing, royalties, and assists. The MVE is filed per operation, so the file has to exist at that grain, not as a company-level summary.
3️⃣ Reconcile your CFDI and XML against the declared value. The declaration binds your fiscal records to your customs value. Where the CFDI, the commercial invoice, and the pedimento disagree, close the gap before the authority reads it for you.
4️⃣ Confirm who prepares and signs. The MVE must be prepared by the importer or its representative. Foreign suppliers without e.firma have a specific path to comply. Confirm which applies to your operation before cargo reaches the border, not while it waits there.
5️⃣ Align your consolidated-pedimento timing. If you clear under pedimento consolidado, the MVE transmits at closing, not per remesa. Your team and your agencia need to agree on that timing in writing so nothing transmits late or twice.
6️⃣ Document the procedure and the retention. Under Regla 1.5.1, the E2 format and its annexes are kept as a digital document for the period the Código Fiscal de la Federación sets. Write the internal procedure now, and name the person who owns the file. A process nobody owns is a process that lapses.
→ We run this exact sequence as a structured MVE readiness review, invoice grain and all, before the transition window closes. If you want a second set of eyes on your value file before September 30, talk to a Joffroy expert.
Will the MVE deadline move again?
It already did. After this article was published, the Segunda Resolución moved the coexistence period to September 30, 2026 and added two documentation facilities that run through December 31, 2026. As of September 21, 2026 that resolution has still not appeared in the DOF, and under regla 1.1.2 its benefits apply from the moment they were made known on the SAT portal.
That history is not a reason to wait. It is the reason not to. An operation that plans to the extension spends every deadline catching up and treats each new date as a reprieve. An operation that plans to September 30 finishes the value-file work once and stops caring which date the authority lands on, because it is ready for any of them. The extension is preparation time the authority handed you. Spent well, it is the difference between transmitting on October 1 and scrambling on it.
What this looks like at Joffroy
We hold three Patentes Nacionales in Mexico, in Monterrey, Nogales, and Manzanillo, plus a US Corporate Customs Brokerage License, and we clear across 39+ ports. The value declarations behind the 190,000+ operations we handle each year are already running on the discipline the MVE now formalizes: value built invoice by invoice, documented at the grain the authority reads, and reconciled before it moves. We track DOF, SAT, and ANAM every business day and translate each change into operational steps before it reaches the border.
The transition period was the easy part. The operations that come out of October 1 without a held shipment are the ones that treated their value file as a system this month, not a scramble next month.
TRADE. UNDER CONTROL.
