US Customs Service
Before entering a foreign country, you will be asked to complete customs declarations forms, which must be presented to immigration and customs inspectors abroad, along with your passport and visa (if required). Customs regulations vary from country to country, so please contact the consulate or embassy of the country you are traveling to for specific information.
If any of your personal effects (such as cameras, cell phones, MP3 players, laptops, etc.) are not made in the U.S., you should register them with U.S. Customs and Border Protection before you leave the U.S. Also, bring receipts or copies of receipts for expensive items so you can prove when and where they were purchased. This will ensure you will not have to pay duties on these items when you return to the U.S.
There are limitations on what you can bring back into the U.S. with you. You should review the U.S. Customs and Border Protection web site to verify what is acceptable, as determined by the U.S. government.
Travel document requirements are changing! Find out what documents are required when you travel outside the United States at US Customs Service. You can also find out the answers about importing INTO the United States.