Since Mexico’s tax authority (SAT) made the Carta Porte supplement mandatory, many exporters and their U.S. partners ask who should issue it, what data it carries and what happens once the freight crosses into the United States. This guide answers those questions in practical terms; it does not replace advice from your accountant or customs agent.
What is the Carta Porte?
The Carta Porte is a supplement attached to a CFDI — Mexico’s electronic invoice — that covers the movement of goods within Mexican territory. Its purpose is to prove lawful possession and transport of the goods: what is being moved, from where, to where, in which vehicle and by whom.
It applies to federal highway trucking and other modes, and it covers international trade shipments: freight leaving your plant in Tijuana for the border must also travel with it.
Who issues it on an export load?
It depends on who performs the move:
- If you hire a carrier, the carrier issues an income CFDI for the freight service with the Carta Porte supplement.
- If the company moves its own goods in its own trucks, it issues a transfer CFDI with the supplement.
Either way, the carrier needs accurate information about the freight from the shipper. If the data arrives incomplete, the Carta Porte will be wrong — and the problem shows up on the highway or at customs.
Data that must be included
The supplement is extensive, but these are the blocks that depend most on you as the shipper:
About the move
- An indicator that it is international transport, when goods leave or enter the country.
- Country of origin or destination and the point of exit or entry.
- Origin and destination addresses, with estimated departure and arrival date and time.
- Distance traveled.
About the goods
- SAT product code from the catalog of transported goods.
- Description, quantity and unit code.
- Weight in kilograms.
- Whether it is hazardous material, with the corresponding code.
- For international trade, the tariff classification and the pedimento reference when applicable.
About the truck and driver
- Type and number of the federal transport permit.
- Vehicle configuration, plates and model year.
- Liability insurance details.
- Trailer details.
- Driver’s tax ID (RFC) and license number.
The carrier provides the last group. What you need to watch is that descriptions, quantities and weights match the commercial invoice and what is actually loaded.
Typical mistake: declaring the weight of the goods without packaging, or in different units than the invoice. It looks minor, but it is one of the inconsistencies that raises the most questions during an inspection.
And on the U.S. side?
The Carta Porte is a Mexican tax requirement; it doesn’t exist in the United States. There, the transport document that travels with the freight is the bill of lading (BOL), and CBP receives shipment data through the carrier’s electronic manifest and the entry prepared by the customs broker. To see how it all fits together, read our Tijuana–San Diego crossing guide.
What if the Carta Porte is wrong or missing?
Moving goods without the CFDI with Carta Porte supplement, or with information that doesn’t match, can lead to fines for the taxpayer and goods being held during an inspection. In addition, SAT does not allow transport expenses supported by an incorrect document to be deducted. Getting it right costs far less than fixing it later.
Quick checklist for shippers
- Keep the SAT code handy for every product you export regularly.
- Always use kilograms and the same units as the commercial invoice.
- Give the carrier complete origin and destination addresses.
- Flag hazardous materials before the trip is scheduled.
- Send the pedimento number as soon as your customs agent generates it.
Note: the supplement version and its filing rules are updated periodically. This guide is informational; confirm current details with your accountant and customs agent.
