Harmonized System Code (HS Code)

The Harmonized System is maintained by the World Customs Organization and used by almost every trading country. The first six digits mean the same thing everywhere; digits after that are national extensions — ten digits in the United States, eight or ten in the EU.

The code drives the duty rate, and it drives the rule of origin, since preferential rules are written per tariff heading. Give at least six digits on a commercial invoice and the destination's full code where you know it.

Classification is the importer's responsibility at destination, and getting it wrong is expensive in both directions: too high and you overpay, too low and you owe the difference plus interest when it is found.