U.S. law requires airlines operating flights that originate from, transit through or are directed to the United States to provide the US Department of Homeland Security (DHS) with certain data on passengers to ensure safe travel and the security of the country. There are two categories of data: Booking (PNR) codes that contain a series of information provided during the booking process or held by airlines or travel agents, such as the passenger's name, address, information on the itinerary of the trip (travel date, origin and destination, seat number, number of bags) and details of the booking (travel agency and payment method) or other information (participation in a frequent flyer programme, for example); advance passenger information (API), consisting mainly of information appearing on the passenger's passport and often collected at check-in. This data is provided prior to arrival to border control authorities and can also be used for checking if passengers are included on lists of people reported for security reasons. The following FAQs relate primarily to PNR data covered by the international agreement of 16 March 2006 between the European Union and the United States. The European Union will make sure that air carriers comply with these obligations. [airline name] must comply with these provisions. For a more comprehensive explanation on the processing of PNR data collected by the DHS in relation to flights between the European Union (EU) and the United States, please refer to the undertakings given by the Department of Homeland Security Customs and Border Protection agency ('PNR undertakings'published in the U.S. Federal Register, volume 64), no. 131, p. 41543, but also as an annex to Commission Decision 2004/535/EC, available by clicking here