Customs tariff is the duty charged on the import of any good into the domestic territory of a country. WTO Member countries are expected to “bind” their customs tariffs, in other words, they are expected to notify the ceiling rates of tariffs. The tariffs which are actually imposed by the Customs authorities on imports into a country are the applied customs tariffs. Each Member is free to set the applied customs tariffs. The only restriction is that the applied tariff of the Member on an agricultural product cannot exceed the bound customs tariff on the product.

For example, the “bound” customs duty on wheat notified to the WTO by India at the end of the Uruguay Round is 70%. Customs duty on wheat imposed by India cannot therefore be increased beyond 70%.