IATA Airline Codes are used to identify an airline for all commercial purposes. the two character airline designator is assigned by IATA in accordance with the provisions of Resolution 762. The two character airline designator listed are for use in reservations, timetables, tickets, tariffs, air waybills, schedules publications and in airline interline telecommunications, as well as for the airline industry applications. IATA assigns three types of two character airline designators. Unique, numeric/alpha and controlled duplicate. (Source: The Airline Codes Website)
IATA codes are an integral part of the travel industry. There are three main coding systems:
- airline designators (e.g. AF = Air France)
- location identifiers (e.g. GVA = Geneva)
- accounting or prefix codes for transport documents (e.g. the accounting code 076 at the beginning of a ticket number identifies it to be a traffic document of Middle East Airlines). The same number can be used for cargo documentation and is known as an “airline prefix”.
These coding systems are essential for the identification of an airline, its destinations and its traffic documents. The codes are fundamental to the smooth running of hundreds of computer systems which have been built around these coding systems for passenger and cargo traffic purposes.
Regarding airline designators, other non-airline companies such as railway, bus and ferry companies, computer reservations systems (CRSs) and ULD owners/leasing companies may also be assigned an IATA airline codes. Airlines that do not qualify for IATA codes but operate at airports with automated baggage sortation systems may be eligible for a baggage tag issuer code.
Regarding location identifiers, bus, rail or ferry locations may be eligible for an IATA code if requested by an airline or CRS. (Source: IATA)
An airline and location code search facility can be found here.