Permission is not protection: what a 2026 Mexican customs service contract must cover

For years, a single document moved your cargo: the carta encomienda (Mexico's commission letter). You signed it, your broker filed it, and the relationship was, for most practical purposes, complete. As of 2026, that document still gets your cargo cleared, but it no longer covers the risk that comes with clearing it. For a CFO or general counsel, that gap is the whole story.

A carta encomienda grants permission. A customs service contract allocates protection. Until this year, most companies treated the first as if it did the work of the second. The 2026 reform to the Ley Aduanera made the difference between the two expensive enough to put on your desk.

A note on scope: this is an operational and risk-management explainer, not legal advice, and Joffroy is not a law firm. The contract that fits your operation should be drafted and reviewed by your own counsel. What follows is what the new framework demands that document address, so you know what to ask for.

The stakes: why a letter stopped being a shield

Start with what changed underneath the paperwork. The reform published in the DOF on November 19, 2025, effective January 1, 2026, made the customs broker a responsable solidario (jointly and severally liable) for the operations they promote, and eliminated the grounds that previously excused them from that responsibility. "The client gave us bad information" is no longer a defense.

That single change rewires the commercial relationship. Your broker is now legally exposed to your data, your materiality, and your tax standing in a way they were not before. They will not, and frankly should not, carry that exposure on the strength of a one-page letter that says nothing about how the two of you handle it. The commission letter authorizes them to act on your behalf. It does not say who is responsible when an audit lands, who updates what and when, or what you have represented to be true.

This is why your broker has started asking for a service contract, or for a materially expanded one. Under the new architecture, the carta encomienda by itself no longer functions as a legal shield; the substance of the relationship has to live in a contract that reflects the obligations both parties now carry.

Here is the number that should worry a CFO more than the legal language: a customs broker can lose their patente. In 2025, ANAM reported 45 administrative proceedings against brokers, 34 patente cancellations, and one suspension (ANAM, Comunicado de prensa 22/2025). If the broker clearing your cargo loses their license, your clearance stops, not in a quarter, today. The contract is partly about liability. It is also about the continuity of the function your supply chain depends on.

What the 2026 customs service contract has to carry

The reform moved the relationship from permission to protection, and the contract is where protection gets written down. Read the reform and Regla 1.4.14 together, and the same categories of obligation recur. Treat the list below as the agenda for the conversation with your counsel and your broker, not as clauses to copy.

The KYC file and your cooperation with it. Regla 1.4.14 of the RGCE 2026 requires your broker to build and safeguard an electronic file on you: corporate documents, powers, tax standing, materiality evidence, declarations under oath. The contract should establish your obligation to provide that documentation and to do so accurately. The broker's compliance now depends on your inputs; the agreement has to say so.

Expediente updates and the trigger to refresh. The file is not a one-time submission. It must be refreshed every three years and whenever previously supplied information changes. The contract should put the obligation to notify on you, with a defined window, because a stale file is the broker's breach, and a broker's breach becomes your delay.

Materiality and the importer's representations. The new standard reaches past legal existence to operational reality: proof that you operate where and how you say you do. The contract should address your duty to support the materiality evidence the file requires, and should capture the declarations the law expects, including that you are not linked, in the terms of Article 68 of the Ley Aduanera, to taxpayers on the SAT watchlists.

The allocation of responsibility for data. With the excluyentes de responsabilidad eliminated, the contract cannot make your broker absorb the consequences of inaccurate information you supply. A 2026 agreement should be explicit about who represents what, who bears the cost of an error, and how the parties cooperate when the authority asks questions.

Audit and information rights. Because the broker is now solidarily liable, they have a legitimate interest in verifying, and re-verifying, what they file for you. The contract should give them the right to request, screen, and update, and should set expectations for how quickly you respond.

A carta encomienda says you may act for me. A 2026 service contract says here is what each of us is responsible for when something goes wrong. The first is permission. The second is protection. The reform made the gap between them the size of a held shipment, or a cancelled patente.

A decision framework for legal and finance

You do not need to become a customs lawyer to govern this well. You need to ask a short list of questions and make sure the answers are written down.

First: does our current arrangement rest on a commission letter alone, or on a service contract that reflects the 2026 obligations? If it is the letter alone, that is the gap to close.

Second: does the agreement assign responsibility for the accuracy of the data we provide, now that our broker can no longer point to our errors as a defense? Silence here is not neutral: it is unallocated risk.

Third: does it obligate us to keep the KYC file current, with a clear trigger and timeline, so a lapse on our side does not become a clearance failure at the worst possible moment?

Fourth: does it give our broker the access they need to verify what they file for us, and does it set our response obligations so verification does not become a bottleneck?

Fifth, and this one is for counsel, not for us: are the representations we are making under oath ones we can actually stand behind? A declaration bajo protesta de decir verdad (under oath, literally "under penalty of telling the truth") is not a formality.

If the answers are clear and documented, your exposure is governed. If they are vague, you are running a regulated, jointly liable operation on a handshake.

Where Joffroy fits, and where your lawyer does

Let us be precise about the boundary. The drafting, negotiation, and legal review of your customs service contract belong to your attorney. We are a customs operator, not legal counsel, and the agreement that fits your structure, your entities, and your risk tolerance is a legal instrument that deserves a lawyer's hand.

What we bring is the operational half of the picture. Across 122 years at the US-Mexico border, 190,000+ annual customs operations, and three Patentes Nacionales, we have learned exactly where these relationships break under audit: which obligations get neglected, which file gaps stall cargo, and how to structure the working relationship so the contract your counsel writes actually holds up in the warehouse and at the line. We will tell your legal team what the operation needs the contract to cover. They will make it enforceable.

The commission letter did its job for a long time. It still has one. But in 2026 it is the beginning of the relationship, not the whole of it, and treating it as the whole is the kind of quiet exposure that stays invisible until the day it isn't. The companies that close the gap now will not notice it again. The ones that don't will notice it on the day a shipment stops moving.

If you want a clear-eyed read on what your customs relationship leaves unallocated before your counsel formalizes it, talk to a Joffroy expert.

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