to provide individual duty-free sales locations and storage cribs with conditionally duty-free merchandise are also Class 9 warehouses. Moreover, in the U.S. some duty-free stores will sell their goods to domestic passengers with appropriate taxes included. Alcohol and tobacco products are restricted to international passengers only and subject to the age limitations of 18 and 21 respectively, even though the age one must be to import those items into other countries may be lower. Visiting U.S. protectorates U.S. citizens receive substantially higher duty exemptions than normal when they visit or transit these locales, e.g., Guam, U.S. Virgin Islands. Competition According to Autogrill / World Duty Free case, duty free is a market where competition is kept both in the EEA market and in the global market. Even with the 2008 merge of the two biggest duty free operators, Autogrill and World Duty Free, they together own less than 10% of the global market and less than 20% of the EEA market. See also Fuel tax, jet fuel used in international flights is sold wholesale List of duty-free shops Tax shopping References External links U.S. Customs and Border Protection Regulations for International Travel by U.S. Residents ("Know Before You Go") Customs duties Borders Retail formats Special economic zones Tax avoidance 1947 introductions