Before individuals travel abroad, it is helpful to learn about U. S. Customs regulations. The regulations apply to things they take from the United States as well as items they bring into the United States from abroad. Foreign-made items taken abroad (e.g. a Swiss watch or Japanese camera) are subject to U. S. Customs duty and tax upon return, unless they have proof they possessed them before they left the United States. A receipt, bill of sale, insurance policy, or a jeweler’s appraisal usually is sufficient proof of prior ownership. In some cases, it may be necessary to register their foreign-made goods that they intend to take on their trip abroad. If they do not have sufficient proof of prior ownership, but their property includes foreign-made items that can be identified by serial number or some other permanent marking, travelers can take them to a Customs office or to the port of departure for registration. There they can obtain a certificate of registration, which can expedite free entry of these items when they return to the United States.