London Heathrow Airport

London Heathrow Airport carries the IATA code LHR — the three letters printed on boarding passes and baggage tags — and the ICAO code EGLL, used in flight plans and by air traffic control. It serves London, United Kingdom.

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.