An import is a commodity brought into a territory, especially across a national border, from an external source. Importation and exportation are the defining financial transactions of international trade. An import in the receiving country is an export from the sending country.

In international trade, the exportation and importation of goods are limited by import quotas and mandates from custom authority. The importing and exporting countries may impose a tariff (tax) on the goods. In addition, the exportation and importation of goods are subject to trade agreements between the importing and exporting countries.

Import consists of transactions in goods and services to a resident of a country from non-residents. The exact definition of imports in national income accounts includes and excludes specific border cases. A general view of imports in national income accounts is given below.

An import of a commodity occurs when there is a change of ownership from non-resident to a resident; the does not necessarily mean that the commodity in question physically crosses the frontier. However, in specific cases, national accounts impute changes of ownership even though in legal terms no change of ownership takes place. For example, cross frontier financial leasing, cross border deliveries between affiliates of the same enterprise, commodities cross the border for significant processing to order or repaid. Also smuggled goods must be included in the import measurement.