in international trade, the granting of mutual concessions in tariff rates, quotas, or other commercial restrictions. Reciprocity implies that these concessions are neither intended nor expected to be generalized to other countries with which the contracting parties have commercial treaties. Reciprocity agreements may be made between individual countries or groups of countries.

The logical extension of reciprocity is the development of a full customs union (e.g., the European Union) that eliminates by progressive mutual concessions all tariffs and other restrictions between participating countries.

Membership in the World Trade Organization (General Agreement on Tariffs and Trade) (WTO) to some extent precludes the establishment of reciprocity treaties, because WTO member countries assume the obligation to grant to all other members most-favoured-nation treatment (extension to member countries of every trade concession made to nonmember countries).