Customs value (valor en aduana) is the base used to calculate Mexico's general import duty. As a rule, it's the transaction value: the price paid for the goods plus the charges the law requires, such as freight and insurance until the goods reach Mexico. It's set out in articles 64 and 65 of Mexico's Customs Law (Ley Aduanera).
It matters for two reasons. First, your import taxes come from that number, so it changes the real landed cost of every unit. Second, it's exactly the value Mexican customs reviews when it suspects undervaluation, and that gets stricter in 2027.
This guide explains the concept. It isn't tax or customs advice: the value of each import is determined with your customs broker.
Transaction value: the starting point
The law defines the price paid as the total payment the importer made or will make to the seller for the goods, directly or indirectly (art. 64). For most brand imports, that's what the supplier's commercial invoice says.
But the invoice price is rarely the full customs value. Article 65 requires adding certain charges if you paid them and they weren't included in the price.
What gets added to the price (art. 65)
| Charge | In plain terms |
|---|---|
| Commissions and brokerage | What you pay an intermediary for the sale. Exception: buying commissions (your buying agent's) aren't added |
| Containers and packing | If, for customs purposes, they form a whole with the goods, plus packing labor and materials |
| Transport, insurance and related costs | Freight, insurance, handling, loading and unloading until the goods reach Mexican territory |
| What you supplied to the manufacturer | Materials, molds, tools or designs you provided free or at a discount to produce the goods |
| Royalties and license fees | If paying them is a condition of sale of those goods |
| Proceeds to the seller | Any part of the resale proceeds that goes back to the seller |
The law is clear on one point: the price is only increased by these items, and based on objective, quantifiable data.
What is NOT added (art. 66)
As long as they're itemized separately from the price on the invoice:
- Freight, insurance and handling after the goods have arrived in Mexico.
- Installation, assembly, maintenance or technical assistance after import.
- Taxes and countervailing duties paid in Mexico because of the import.
The itemization condition matters: if your supplier bills the product and freight all the way to your warehouse in Guadalajara as one line, customs has no way to separate the part that shouldn't be added.
A worked example
Say you're buying apparel from a supplier in Asia. The numbers are illustrative:
| Item | Amount |
|---|---|
| Invoice price (delivered at the origin port) | US$10,000 |
| Ocean freight to Manzanillo | US$1,200 |
| Cargo insurance | US$100 |
| Customs value | US$11,300 |
| Freight from Manzanillo to your warehouse, itemized | Not added |
Mexico's general import duty is calculated on that US$11,300 (converted to pesos at the applicable exchange rate), at a rate that depends on your product's tariff classification. And import VAT isn't calculated on customs value alone: the import duty and other contributions paid on the import are added to it, under article 27 of Mexico's VAT Law.
How it relates to Incoterms
The Incoterm (the international sales term) doesn't change the rule. It changes what's already inside the price:
- If you buy EXW or FOB, the invoice doesn't include international freight or insurance: you have to add them.
- If you buy CIF, freight and insurance to the destination port are already in the price.
If you're not sure what each term covers, see Incoterms 2020: who pays what.
When there's no transaction value
Some imports don't come from a normal sale: a free sample, goods between related companies whose price can't be accepted, a consignment shipment. For those, article 71 sets methods applied in order, moving to the next only if the previous one doesn't work:
- Transaction value of identical goods.
- Transaction value of similar goods.
- Unit sale price.
- Computed value (production cost plus expenses and profit).
- The article 78 method, as a last resort.
The importer may swap the order of 3 and 4.
Customs value and undervaluation
Undervaluing means declaring a lower value than the correct one. Beyond the legal risk, it's bad math: what you "save" in taxes can cost you held goods, which is inventory you can't sell. A reform that toughens precautionary seizures for undervaluation takes effect on January 1, 2027; we explain it in Mexico's customs reform on undervaluation.
Customs value is declared on the pedimento, Mexico's import declaration. To find it on the document, see how to read an import pedimento.
FAQ
Is customs value the same as commercial value? Not always. Commercial value is the invoice price; customs value is that price plus the article 65 charges (such as freight and insurance to Mexico) when they weren't included.
Is freight within Mexico added? No, as long as it's itemized separately from the price. What's added is transport until the goods reach Mexican territory.
Who determines customs value? You, as the importer, with your customs broker, who declares it on the pedimento. Customs can review it afterward.
Ecommex isn't a customs broker: you declare the value with yours. What we do in inventory import for e-commerce is coordinate with brokers, ocean carriers and truckers, and receive your goods at our fulfillment center in Zapopan, counting them against the commercial invoice.