Importing to Mexico: the customs documents you need

Importing from China to Mexico requires seven documentary requirements, and the order in which they are resolved decides whether the cargo is unloaded or held: RFC, padrón de importadores, tariff classification, NOM certification where the category demands it, customs broker, pedimento and commercial documents. The first three are settled before paying the supplier. The NOM, if it applies, before the goods leave the factory, because the laboratory tests finished product. Cargo that arrives at port without the applicable NOM is not released with a formality: it stays in storage while the matter is resolved.

Who appears as the importer decides everything else

In Mexico, the importer of record must be a natural or legal person with an RFC and the legal capacity to import, and that does not change because the shipment is negotiated on DDP terms. DDP allocates cost and risk, but it does not replace the party Mexican law recognises as the importer: without an RFC on the Mexican side there is no formal import, there is a delivery.

Negotiating on DDP does not turn the Chinese seller into your Mexican importer. Behind the price there has to be a Mexican entity with an RFC that appears on the pedimento. If your supplier cannot tell you which entity that is, the question is still open.

1. RFC: without Mexican tax identification there is no formal import

The RFC is the first document on the list because it is what makes the importer exist before the SAT. With that key the importer is enrolled in the padrón, the pedimento is filed and the contributions are determined. Registration requires being active in the RFC, holding a valid e.firma and having a validated Buzón Tributario, among other conditions published by the SAT.

A person without an RFC cannot import goods intended for resale. Receiving a shipment for personal use is a different case.

2. Padrón de importadores: the registration that authorises importing

The padrón de importadores is the SAT register in which anyone who imports goods on a habitual basis must be enrolled. It is a requirement of the person, not of the product.

There is also a padrón of specific sectors, for particular categories of goods. The SAT publishes the list of sectors and tariff lines covered. Chemicals, textiles, footwear, steel, automotive and hydrocarbons appear frequently, but the list is updated: what counts is the version in force.

Being registered is not a permanent status. The SAT publishes registers of active and suspended importers, and suspension halts the operation until reinstatement.

3. Tariff classification: the datum everything else depends on

The fracción arancelaria is your product’s key in the tariff schedule — in Mexico, the TIGIE — and the applicable duty, the unit of measure, whether the product falls within the scope of a NOM and whether it requires a prior permit or an automatic notice all depend on it. No other piece can be resolved before this one, because all of them consult it.

Misclassifying is among the most common causes of detention and of later adjustments.

4. NOM certification: before shipment, not after

If your product falls within the scope of a Norma Oficial Mexicana, the certificate has to exist when the goods are presented for clearance, and since the laboratory tests finished product, that means obtaining it before the cargo leaves the factory. The NOM is not a customs formality: it is a restriction decided at the design stage.

There is no single NOM for all electronics: there is one per category, and which applies depends on what the device does, where it draws its current from and whether it emits radio. The detail by category is in our electronics from Shenzhen reference.

The certificate is issued by a certification body accredited in Mexico. A test report issued in China does not replace it.

5. Customs broker: a regulated profession, not a commercial service

In Mexico the clearance is filed by the importer or the exporter, or by an agente or agencia aduanal acting as their consignee or mandatory, under article 40 of the Ley Aduanera. A legal person that clears without a broker does so through a legal representative accredited before the SAT.

The agente aduanal is a natural person authorised by patent, and the patent is personal and non-transferable. Article 159 of the Ley Aduanera requires, among other conditions, Mexican nationality by birth, a professional degree, more than five years of experience in foreign trade and passing a knowledge examination and a psychometric assessment.

Neither you nor your supplier in China can clear the goods: it is done by a third party qualified in Mexico.

6. Pedimento: the declaration that executes the clearance

The pedimento is the declaration in electronic document form with which the customs regime is declared and the contributions are determined, and it is presented together with the goods at the automated selection mechanism. It is prepared and signed by the agente aduanal using the importer’s information.

It is also your import tax receipt. If the pedimento is not in your name, you have nothing with which to prove the import and nothing with which to deduct: the cost of third-party importer schemes is fiscal, not logistical.

The customs terms used in this guide — pedimento, padrón de importadores, agente aduanal, fracción arancelaria — are defined in the glossary.

7. Commercial invoice, packing list and transport document

All three travel with the cargo and have to be consistent with one another in value, weight, quantity and description. A discrepancy between the invoice and the packing list is what customs detects and turns a routine clearance into a few days of detention.

• Commercial invoice. Issued by the supplier, with the description aligned to the fracción arancelaria.
• Packing list. Sets out packages, weights and dimensions.
• Bill of lading or air waybill. Establishes who the consignee is.

Correcting them with the cargo at the terminal is expensive; at the origin warehouse, cheap. In a consolidated operation, coordinating the shipping documents is part of the MeliPrep commission, alongside the cargo consolidation itself.

The table: what each document produces and what happens if it is missing

What varies and has to be confirmed on every shipment

None of this is a form you fill in once. Four points change from one shipment to the next:

• The applicable duty, according to the fracción arancelaria. It varies by product and by subcategory. A quotation that gives a figure without the classification in front of it is not a quotation.
• Whether a NOM applies to your specific product. It depends on the characteristics of the item — where it draws its power from, whether it emits radio, at what voltage it works — not on the commercial category.
• Whether the fracción requires a prior permit or an automatic notice. It is checked with the classification done.
• The treatment in force of the regime you use. In May 2026 an agreement published in the DOF withdrew the facility of the simplified scheme for mobile phones. What was true last year may not be true today.

If something depends on your classification or on your tax situation, it is confirmed with the rule in force in front of you.

The deadline trap: when the NOM is requested after shipment

A NOM requested after shipment does not turn into a late formality: it turns into detained cargo. The laboratory needs units of the finished product, and obtaining them means producing them. If the goods have already left the factory, those units no longer exist.

The ways out are all expensive: re-export, destroy within a fiscalised premises or regularise by paying the penalty. On top of that comes the storage while the certificate is issued, which runs at the product owner’s expense.

The sequence that avoids the scenario is short: classify the product, check whether the category is subject to a NOM, contract the test on finished product and only then book freight. If the product needs changes in order to pass the test, they are made on the production line and not in a warehouse at destination.

Mexico, Argentina and Brazil: the same sequence, different registers

The logic repeats in all three markets, but the names, the registers and the authorities are not the same, and none of them is resolved from China.

In Argentina the most frequent confusion is about the regime, not the document. The simplified door-to-door regime is limited to personal use and excludes resale; anyone importing in order to resell goes through the general regime, with a CUIT, registration as an importer and a qualified despachante.

In Brazil the first filter is homologation, not the padrón. Importing telecommunications products intended for commercialisation is permitted only with prior ANATEL homologation.

This describes the process; it is not tax or customs advice

This article explains how the mechanism works; it is not tax, customs or legal advice, and it does not replace reading the rule in force. Which RFC to operate under, which regime to choose, how to classify your product and what certifications it needs are decisions for your accountant and your customs broker, who are the ones who answer to the authority.

What can be done from the Chinese side is to prepare the inputs: exact technical description, composition, electrical specification, intended use and manufacturer documents. The more precise that information is at origin, the fewer assumptions the destination clearance has to make. Confirming the lot against that information before it leaves China is what a pre-shipment quality inspection does.

MeliPrep coordinates the origin documentation, the certification when the laboratory works on product from the order, and the consolidation before shipment, with the laboratory fees billed at cost. The fiscal decision and the signature on the clearance stay on the Mexican side.