APIS
Advance Passenger Information System is the electronic transmission of passenger and crew passport details to a country's border authority before an international flight departs. The United States requires it for all private flights arriving in or leaving the country, generally at least 60 minutes before departure, and the operator must receive a clearance message before take-off; the EU, UK, Mexico, India, Brazil, China and many others run equivalents. This is the practical reason charter operators need everyone's passport details a day or more in advance and why adding a passenger at the airport is often impossible on an international flight. Data goes through the operator or its trip-support provider.