Washington Dulles International Airport

Washington Dulles International Airport carries the IATA code IAD — the three letters printed on boarding passes and baggage tags — and the ICAO code KIAD, used in flight plans and by air traffic control. It serves Dulles, United States.

IATA codes are assigned by the International Air Transport Association for passenger-facing use; the four-letter ICAO code encodes region and country and belongs to the operational side of aviation.