Which WTO agreement sets rules for customs valuation based primarily on the transaction value of imported goods?

The Agreement on Customs Valuation sets WTO rules based primarily on the transaction value of imported goods. This means customs value normally begins with the price actually paid or payable for the goods when sold for export to the importing country.

If the transaction-value method cannot be used, the agreement provides five alternative methods applied in a prescribed order. These include the value of identical goods, similar goods, a deductive method, a computed method, and a fallback method.

The system aims to prevent arbitrary or fictitious customs values from being used to raise import charges. It is different from the Harmonized System, which classifies products using tariff codes, and from rules of origin, which determine where goods are considered to come from. Customs valuation concerns the value assigned to imported goods.