Carta Porte in Mexico, explained for US shippers

In short: the Carta Porte complement is Mexico’s digital freight-documentation requirement: a structured attachment to the Mexican e-invoice (CFDI) that records what is being transported, between which points, in which vehicle and by whom. Version 3.1 has been the only valid version since July 2024 (catalogs refreshed January 2026). It does not apply to your US leg — it applies the moment your freight moves on Mexican federal highways, which is why your Mexican carrier keeps asking you for clean shipment data.

Editorial note. General information, not legal, tax or customs advice. The standard and its catalogs change; the authoritative source is Mexico’s SAT. Independent editorial resource operated by Heberey LLC; not affiliated with SAT, CBP or any authority.

The one-paragraph mental model

Think of Carta Porte as the transport twin of the customs entry. The pedimento tells Mexican authorities what crossed the border and under which regime; the Carta Porte tells them what is rolling down the highway right now. Both are checked, and both must match each other — and match your invoices and warehouse receipts.

Where it bites a US shipper: the Laredo handoff

In the classic cross-border move — US carrier to the border, transload or cross-dock in Laredo, Mexican carrier south — the obligation lands on the Mexican leg:

• The Mexican carrier hauling your goods for hire issues a CFDI de ingreso (income invoice) with the Carta Porte complement.
• A company moving its own goods in its own trucks issues a CFDI de traslado (transfer invoice) with the complement.

Your US paperwork does not satisfy this. If the Mexican carrier does not have the data to issue a valid complement before the truck leaves the yard, your freight waits.

What your carrier actually needs from you

The complement demands structured data the carrier cannot guess:

The most common failure is not a missing document; it is a mismatched one: descriptions that differ from the invoice, quantities that differ from the packing list, an origin that contradicts the pedimento. Each mismatch is a future question in an audit — the same reconciliation discipline we describe for inventory control applies here.

Version 3.1 and the 2026 catalog update

Version 3.1 became mandatory in July 2024 and remains the only valid schema. In January 2026 SAT refreshed the catalogs (the valid values used to fill the fields) — not the schema. Practical takeaway when a carrier or software vendor says “we are compliant”: ask whether they are on the current catalogs, not just the 3.1 schema.

Penalties, and the cost that matters more

Mexico’s Federal Tax Code provides fines per movement made without a required complement, and the document is checked on highways and at crossings. But for a US shipper the more frequent cost is operational: held trucks, blown delivery appointments, missed cross-dock windows — and, for temporary-import cargo, a weaker documentary record. (You can watch what border timing looks like on our live Laredo wait-time radar.)

Questions to ask your Mexican carrier or broker

1. Who issues the CFDI with the Carta Porte complement for my southbound leg — and when?
2. What data do you need from me, in what format, and by what cutoff?
3. Are you on Carta Porte 3.1 with the January 2026 catalogs?
4. How do you make sure the complement matches the commercial invoice and the pedimento?
5. What happens to my freight if the complement is rejected — who fixes it and how fast?

A carrier who answers these crisply is telling you their Mexican compliance is real. Vague answers here predict trucks parked at the border.

Recommended official sources

• SAT — Carta Porte minisite (standard, catalogs, FAQ; Spanish);
• DOF — the underlying rules and facilities;
• your Mexican carrier and customs broker for route-specific detail.