AirportsIATA and ICAO airport codes
Every airport with airline flights has two codes. Passengers meet one of them. Pilots use the other.
IATA codes: three letters, for passengers
IATA is the International Air Transport Association, the trade body of the airlines. Its three-letter codes are the ones on tickets, boarding passes, departure boards and baggage tags. DEL is Delhi, LHR is London Heathrow, JFK is New York John F. Kennedy.
The code usually comes from the name of the city or the airport. When the obvious letters were taken, another letter was added or changed. Many codes keep an old name: BOM for Mumbai (Bombay), MAA for Chennai (Madras), CCU for Kolkata (Calcutta), ORD for Chicago O'Hare (Orchard Field).
ICAO codes: four letters, for pilots
ICAO is the International Civil Aviation Organization, an agency of the United Nations. Its four-letter codes are used in flight plans, by air traffic control and in weather reports. Unlike IATA codes, they follow a map. The first letter gives a region of the world and the second usually gives the country. Delhi is VIDP: V for South Asia, I for India, DP for Delhi Palam. London Heathrow is EGLL: E for northern Europe, G for Great Britain.
In the mainland United States the ICAO code is simply K plus the IATA code, so JFK becomes KJFK. In Canada it is C plus the IATA code: YYZ becomes CYYZ.
Side by side
| IATA | ICAO | |
|---|---|---|
| Letters | Three | Four |
| Used by | Airlines, travel agents, passengers | Pilots, air traffic control, weather services |
| Seen on | Tickets, baggage tags | Flight plans, charts |
| Pattern | From the city or airport name | Region, then country, then airport |
| Who has one | Mostly airports with airline flights | Almost every airfield, even small ones |
City codes
A few large cities with several airports also have a code for the whole city. LON covers all London airports and NYC all New York airports. A search for LON looks at Heathrow, Gatwick, Stansted and the others together.
Reading your baggage tag
The large three letters on a baggage tag are the IATA code of the airport where the bag should come off. If you change planes, the tag lists each stop, and the last code is your destination. It is worth a glance at the check-in counter. Look up any code.