Most-Favored Nation Tariffs

MFN tariffs are what countries promise to impose on imports from other members of the WTO, unless the country is part of a preferential trade agreement (such as a free trade area or customs union). This means that, in practice, MFN rates are the highest (most restrictive) that WTO members charge one another.

Some countries impose higher tariffs on countries that are not part of the WTO. In some rare cases, WTO members/GATT contracting parties have invoked the "Non-Application Clause" of WTO/GATT agreements and chosen not to extend MFN treatment to certain other countries.

Preferential Tariffs

Virtually all countries in the world joined at least one preferential trade agreement, under which they promise to give another country's products lower tariffs than their MFN rate. In a customs union (such as the Southern Africa Customs Union or the European Community) or a free trade area (e.g., NAFTA), the preferential tariff rate is zero on essentially all products. These agreements are reciprocal: all parties agree to give each other the benefits of lower tariffs. Some agreements specify that members will receive a percentage reduction from the MFN tariff, but not necessarily zero tariffs. Preferences therefore differ between partners and agreements.

Many countries, particularly the wealthier ones, give developing countries unilateral preferential treatment, rather than through a reciprocal agreement. The largest of these programs is the Generalized System of Preferences (GSP), which was initiated in the 1960s. The European Union, Japan, United States offer multiple unilateral preference programs. The EU's Everything But Arms (EBA) program is one example. Exporting countries may have access to several different preference programs from a given importing partner and for a given product.