What are Airline Codes?

While airports around the world have their own unique three letter code, with a growing number of airline companies, there was an urgent need to name the airlines as well. The naming of airlines was important for a number of reasons. For one, it helped air traffic controllers keep a proper track of the flights and the flight path to avoid confusion. Also, the code helps keep a more systematic approach, with airlines having their own designated codes. However, the codes are different than the IATA airport codes.

Airline codes are used by the aviation industry to make the identification of airlines, and flights. Such codes provide an easy way of communication between the aviation industry. There are three major codes International Civil Aviation Organization (ICAO) codes, International Air Transport Association (IATA) codes and Call Signs.


The IATA system for airline codes is different than its system employed for airport codes. These codes are also known as reservation codes, and it has been around for more than twenty years. They have two alphanumeric characters, and there is a third optional character. This code identifies an airline. It carries three types of designators

  • Unique
  • Numeric or Alpha
  • Controlled Duplicate

These designators are used in places like schedules, tickets, air waybills, tariffs and in telecommunications. In case, airline has been delisted; the code is available for reuse after 6 months. They will be used as controlled duplicates, which is limited to regional airlines. In addition, IATA issues a prefix code, which is found on tickets as first three characters of ticket number.


ICAO airline designators are code issued for aircraft agencies, aeronautical authorities, and other aviation services. These codes are unique for each airline. They were introduced in 1947 as two-letter system but as the airlines grew, they introduced three-letter system. For example, American Airlines is designated as AAL (AA is two letter ICAO designator). Sometime ICAO and IATA codes for airline are same. Y and Z letter combinations are only reserved for governmental and military organizations. For operators that do not have designated codes use YYY.

Call Signs

Call signs are flight identifiers or also known as flight ID. These are used only during radio transmissions between airport authorities. There are generally of three types.

1. Type A

This type has characters that represent registration marking of an aircraft.

2. Type B

This type contains a telephone designator of airline, which is followed by last four characters of aircraft registration marking.

3. Type C

In this type, the telephony designator is followed by flight identification code.

Currently, Type C is widely used for commercial aviation. Most of the time flight identification is same as that of flight number. The flight number is always used for public convenience at the airport.