
However, some countries inflict duty on goods brought into the country, though they had been bought duty-free in another country, or when the value or quanity of such goods exceed an allowed limit. Duty free shop are often found in the international zone of worldwide airports and sea ports, but goods can be also bought duty-free on board airplanes and traveller ships. They are not as commonly available for road or train travelers, although several border crossings between the United States and Canada have duty free shop for car travelers.