The island is a duty-free port, which means there are no restrictions on what is brought to the island. Naturally, prohibited goods such as drugs, firearms and explosives may not be freely imported and should be declared when clearing in. Failure to do so will result in serious consequences.
US citizens , regardless of age, who have been out of the country for a minimum of 48 hrs and have not used their respective duty-free allowance within 30 days are entitled to a $600 duty-free tax exemption. Families traveling together can pool their exemptions . Alcohol: The duty-free allowance for US citizens age 21 and over is one quart, the value of which must be included within the $600 exemption.
Canadian citizens who have been out of the country for a minimum of 7 days are entitled to a duty-free exemption of $750 Cdn. They are also permitted a duty-free exemption of $200 Cdn each time they are out of the country for more than 48 hrs. This $200 exemption may not be claimed during the same period as the $750 exemption, nor can your exemptions be pooled with your spouse and/or children . Alcohol: The duty-free allowance for Canadian citizens who meet the legal age of the province they re-enter is 40 ounces of wine or liquor or two dozen 12-ounce cans of beer, the value of which must be included within the yearly or quarterly exemption.
Currency: Traveler checks and major credit cards are widely accepted. ATM machines are located all over the island. U.S. Dollars are accepted at most locations. However, some French side stores give cash back in Euros.