What IATA code means
IATA codes are the shorthand of airline reservations. They appear in flight numbers, availability displays, fares, tickets and bag tags. Three families matter for travel professionals.
Airline designators are two characters and are assigned under IATA Passenger Services Conference Resolution 762. IATA says companies holding a designator use it for reservations, schedules, timetables and other commercial purposes. Codes can mix letters and digits, such as 5Y for Atlas Air. Some codes are controlled duplicates shared by two carriers with separate, non-overlapping operations, and IATA marks these with an asterisk. In 2026, IATA listed its application and assignment fee as USD 6,900 per code.
Location codes are three letters, assigned under Resolution 763 so that each code is unique. IATA's fact sheet says about 17,000 combinations are possible and roughly 11,300 are in use, with 40 to 50 new codes issued a year. Where a city has several airports, a separate metropolitan code can group them: Washington's DCA, IAD and BWI share the city code WAS. Codes can also be given to rail or ferry stations that form part of an intermodal ticketed journey.
Accounting or prefix codes are three digits and identify passenger and cargo documents, such as the first three digits of an e-ticket number.
These are commercial codes. Air traffic control and flight planning use different ICAO codes.
How IATA code works
IATA assigns codes on request and keeps them stable so that systems around the world can rely on them.
- An application is madeAn airline applies for a designator or accounting code, or an airline or CRS requests a location code for a new airport or station.
- Eligibility is checkedFor designators, scheduled airlines must show an air operator certificate and published schedules; non-scheduled carriers must meet other interline or messaging conditions.
- A code is chosenFor locations, IATA prefers an unused code from the first three letters of the name, then another combination ideally starting with its first letter.
- The code is publishedAssigned codes enter IATA's coding databases and its public code search, and then flow into GDSs and airline systems.
- Codes stay stableLocation codes are almost never changed, and then usually only for safety reasons, because so many systems depend on them.
IATA code in practice
| Type | Example | Meaning |
|---|---|---|
| Airline designator | QR | Qatar Airways |
| Airline designator (alphanumeric) | 5Y | Atlas Air |
| Airport and city, same code | GVA | Geneva |
| Metropolitan code | WAS | Washington (DCA, IAD, BWI) |
| Accounting code | 075 | Iberia ticket prefix |
Put together, a single booking line can carry several IATA codes at once: the airline designator in the flight number, the departure and arrival airport codes, and, once ticketed, the airline's accounting code at the start of the ticket number. A shopper searching WAS rather than IAD sees flights from all three Washington airports. IATA notes that Los Angeles moved from the two-letter LA to LAX in 1947 when two-letter codes ran out, and that Washington Dulles was changed from DIA to IAD to avoid confusion with DCA.
Who uses it
Advantages and limitations
Advantages
- Short, unique codes make reservations messages compact and unambiguous.
- City codes let shoppers search several airports at once.
- Stable assignments mean systems worldwide can rely on the same codes for decades.
- A public code search lets anyone check what a code means.
Limitations
- Airline designators can be reassigned after a carrier ceases, so old data may point to a different airline.
- Controlled duplicates mean a two-character code alone may not identify one carrier.
- IATA codes do not cover every airfield; many small or non-commercial airports have only ICAO or national codes.
- Full coding databases are commercial products, so free lookups are limited.
Frequently asked questions about IATA code
Why do some IATA airport codes not match the city name?
Codes are assigned only if unused, so the obvious letters may already be taken. Others are historical: IATA notes that many Canadian codes start with Y for reasons dating from before the Second World War. Dubai uses DXB partly because DUB was already Dublin's code.
What is the difference between an IATA airport code and a city code?
When one airport serves a city, the airport and city share one code, as with Geneva (GVA). Where several airports serve a metro area, each airport has its own code and a separate city code may group them, such as WAS for Washington. Searching the city code returns flights from all its airports.
Can two airlines have the same IATA code?
Yes, in limited cases. IATA issues controlled duplicate designators, marked with an asterisk, to carriers whose operations do not overlap. Non-scheduled carriers may receive a duplicate code but cannot publish schedules with it. In everyday booking, scheduled airlines use their own unique primary code.
How do I look up an IATA airline or airport code?
IATA offers a free official code search on its website that returns the airline for a two-character designator or the airport for a three-letter code, and vice versa. GDSs also include encode and decode commands, and IATA sells full coding databases for system integration.
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