Understanding Airport Codes

Learn the difference between IATA and ICAO airport codes and when to use each.

Airport codes are standardized identifiers used in aviation and travel. Understanding IATA and ICAO codes is essential for developers building travel applications, flight tracking systems, and aviation software.

IATA Codes Explained

IATA (International Air Transport Association) codes are 3-letter codes used commercially. Passengers see these on boarding passes and airport displays. Examples include JFK (New York), LHR (London Heathrow), and NRT (Tokyo Narita). IATA codes are designed to be memorable and often relate to the city or airport name.

ICAO Codes Explained

ICAO (International Civil Aviation Organization) codes are 4-letter codes used in flight planning and air traffic control. They follow a regional structure—K prefix for US (KJFK), E for Northern Europe (EGLL for Heathrow), and so on. Pilots and aviation professionals use these codes.

When to Use Each Code Type

Consumer-facing applications typically use IATA codes since travelers recognize them. Aviation applications, flight data feeds, and ATC systems use ICAO codes. Many APIs support both, and conversion between them is common.

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