口岸是设有边防检查的边界地点。在主要通商的口岸设置边界关卡，包括海关、出入境管理及检疫设施。

旅客需要护照、签证等文档，在政府特定的口岸，获得进出边界有关国家的权利。

口岸是指由政府指定的对外出入境的边界关卡。由官员运行出入境管制操施：检查经海、陆、空三路出入境旅客的护照及/或签证等出入境手续；检查行李以阻止走私违禁品出入境。按照出入境的国境的交通方式划分，可将口岸分为港口口岸、陆路口岸和航空口岸。国际机场兼备为航空口岸。设有边防检查设施的港口便可成为港口口岸，提供船舶货物和旅客进出国境。互通一个陆路口岸，须要与陆邻国家的协商。

In general, a port of entry (POE) is a place where one may lawfully enter a country. It typically has a staff of people who check passports and visas and inspect luggage to assure that contraband is not imported. International airports are usually ports of entry, as are road and rail crossings on a land border. Seaports can be used as ports of entry only if a dedicated customs presence is posted there. The choice of whether to become a port of entry is up to the civil authority controlling the port.