IATA airport code


An IATA airport code, also known as an IATA location identifier, IATA station code, or simply a location identifier, is a unique three-letter geocode designating many airports, cities and metropolitan areas around the world, defined by the International Air Transport Association. The characters prominently displayed on baggage tags attached at airport check-in desks are an example of a way these codes are used.
The assignment of these codes is governed by IATA Resolution 763, and it is administered by the IATA's headquarters in Montreal, Canada. The codes are published semi-annually in the IATA Airline Coding Directory.
IATA also provides codes for airport handling entities, and for certain railway stations.
Alphabetical lists of airports sorted by IATA code are available. A list of railway station codes, shared in agreements between airlines and rail lines such as Amtrak, SNCF, and Deutsche Bahn, is available. However, many railway administrations have their own list of codes for their stations, such as Amtrak station codes.

History

Airport codes arose out of the convenience that the practice brought pilots for location identification in the 1930s. Initially, pilots in the United States used the two-letter code from the National Weather Service for identifying cities. This system became unmanageable for cities and towns without an NWS identifier, and the use of two letters allowed only a few hundred combinations; a three-letter system of airport codes was implemented. This system allowed for 17,576 permutations, assuming all letters can be used in conjunction with each other.
In the early days of aviation, airport codes frequently adopted the naming conventions previously established by weather stations, railway stations, and other commercial or governmental outposts that communicated by radio or telegraph. The code names for those stations, which usually predated the use of two-way radio and even radiotelephony itself, reflected the need for terse, standardized signaling patterns that could be easily transmitted and correctly received via radiotelegraphy and Morse code.

Naming conventions

National policies

Canada

Canada's unusual codes, which bear little to no similarity with any conventional abbreviation to the city's name, originated from the two-letter codes used to identify weather reporting stations in the 1930s. The letters preceding the two-letter code follow the following format:
  • Y – for "Yes", this letter was used when the station shared its location with an airport.
  • W – for "Without", when the weather-reporting station did not share its location with an airport.
  • U – used when the station was located together with a non-directional beacon.
  • X – suggesting that the last two letters of a code were already in use by a Canadian airport.
  • Z – indicated that an airport code had been used for the identification of an airport in the U.S.
Most large airports in Canada have codes that begin with the letter "Y", although not all "Y" codes are Canadian, and not all Canadian airports start with the letter "Y". Many Canadian airports have a code that starts with W, X or Z, but none of these are major airports. When the Canadian transcontinental railways were built, each station was assigned its own two-letter Morse code:
When the Canadian government established airports, it used the existing railway codes for them as well. If the airport had a weather station, authorities added a "Y" to the front of the code, meaning "Yes" to indicate it had a weather station or some other letter to indicate it did not. When international codes were created in cooperation with the United States, because "Y" was seldom used in the United States, Canada simply used the weather station codes for its airports, changing the "Y" to a "Z" if it conflicted with an airport code already in use. The result is that most major Canadian airport codes start with "Y" followed by two letters in the city's name, based on the transcontiential railroad two-letter Morse code, as mentioned above, whereas other Canadian airports append the two-letter code of the radio beacons that were the closest to the actual airport, such as International Airport|YQX] in Gander or YXS in Prince George.
Four of the ten provincial capital airports in Canada have ended up with codes beginning with YY, including:
Canada's largest airport is YYZ for Toronto Pearson. YUL is used for Montréal–Trudeau and Vancouver International Airport.

New Zealand

Numerous New Zealand airports use codes that contain the letter Z, to distinguish them from similar airport names in other countries. Some examples are HLZ for Hamilton, ZQN for Queenstown, and WSZ for Westport.

United States

Since the United States Navy reserved "N" codes, and to prevent confusion with Federal Communications Commission broadcast call signs, which begin with "W" or "K", the airports of certain U.S. cities whose name begins with one of these letters had to adopt "irregular" airport codes:
This practice is not followed outside the United States:
In addition, since three letter codes starting with Q are widely used in radio communication, cities whose name begins with "Q" also had to find alternate codes, as in the case of:
Even this practice is not followed universally. For instance Owerri in Nigeria uses the code QOW.
IATA codes should not be confused with the FAA identifiers of U.S. airports. Most FAA identifiers agree with the corresponding IATA codes, but some do not, such as Saipan, whose FAA identifier is GSN and its IATA code is SPN, and some coincide with IATA codes of non-U.S. airports.

Naming conventions in general

Many airport codes consist of the first three letters of the city where the airport is located, for instance:
The code may also be another combination of the letters in the city's name, such as:
Sometimes the airport code reflects pronunciation, rather than spelling, for example:
For many reasons, some airport codes do not fit the normal scheme described above. Some airports, for example, cross several municipalities or regions, and therefore use codes derived from a combination of their letters, resulting in:
Other airports—particularly those serving cities with multiple airports—have codes derived from the name of the airport itself, for instance:
This is also true with some cities with a single airport, such as BDL for Hartford, Connecticut's Bradley International Airport or Baltimore's BWI, for Baltimore/Washington International Airport; however, the latter also serves Washington, D.C., alongside Dulles International Airport and Ronald Reagan Washington National Airport.
The code also sometimes comes from the airport's former name, such as Orlando International Airport's MCO, or Chicago's O'Hare International Airport, which is coded ORD for its original name: Orchard Field. In rare cases, the code comes from the airport's unofficial name, such as Kahului Airport's OGG.

Cities with multiple commercial airports

In large metropolitan areas, airport codes are often named after the airport itself instead of the city it serves, while another code is reserved which refers to the city itself which can be used to search for flights to any of its airports. For instance:
Or using a code for the city in one of the major airports and then assigning another code to another airport:
When different cities with the same name each have an airport, they need to be assigned different codes. Examples include:
Sometimes, a new airport is built, replacing the old one, leaving the city's new "major" airport code to no longer correspond with the city's name. The original airport in Nashville, Tennessee, was built in 1936 as part of the Works Progress Administration and called Berry Field with the designation, BNA. A new facility known as Nashville International Airport was built in 1987 but still uses BNA. This is in conjunction to rules aimed to avoid confusion that seem to apply in the United States, which state that "the first and second letters or second and third letters of an identifier may not be duplicated with less than 200 nautical miles separation." Thus, Washington, D.C. area's three airports all have radically different codes: IAD for Washington–Dulles, DCA for Washington–Reagan, and BWI for Baltimore. Since HOU is used for William P. Hobby Airport, the new Houston–Intercontinental became IAH. The code BKK was originally assigned to Bangkok–Don Mueang and was later transferred to Suvarnabhumi Airport, while the former adopted DMK. Meanwhile, Tan Son Nhat Airport keeps its Saigon-inspired SGN code even though the city has long been renamed to Ho Chi Minh City, and the city's new primary airport Long Thanh International adopts a brand new code LTH after its own name rather than any derivatives from the name of the city that it serves or the legacy SGN designation. The code ISK was originally assigned to Gandhinagar Airport and later on transferred to Ozar Airport. Shanghai–Hongqiao retained the code SHA, while the newer Shanghai–Pudong adopted PVG. The opposite was true for Berlin: the airport Berlin–Tegel used the code TXL, while its smaller counterpart Berlin–Schönefeld used SXF; the Berlin Brandenburg Airport, which reuses much of Schönefeld's infrastructure, has the airport code BER, which is also part of its branding. The airports of Hamburg and Hannover are less than apart and therefore share the same first and middle letters, indicating that this rule might be followed only in Germany.

Cities or airports changing names

Many cities retain historical names in their airport codes, even after having undergone an official name/spelling/transliteration change:
Some airport codes are based on previous names associated with a present airport, often with a military heritage. These include:
Some airports are named for an administrative division or nearby city, rather than the one they are located in:
Other airport codes are of obscure origin, and each has its own peculiarities:
In Asia, codes that do not correspond with their city's names include Niigata's KIJ, Nanchang's KHN and Pyongyang's FNJ.

Multiple codes for a single airport

EuroAirport Basel Mulhouse Freiburg, which serves three countries, has three airport codes: BSL, MLH, EAP.
  • The French part of the airport is assigned MLH, for Mulhouse, France
  • The Swiss part of the airport is assigned BSL, for Basel, Switzerland
  • The airport also has a Metropolitan Area Code, EAP, for EuroAirport.

Airport codes using the English name of the city

Some cities have a local name in their respective language which is different from the name in English, yet the airport code represents only the English name. Examples include:

Scarcity of codes

Due to scarcity of codes, some airports are given codes with letters not found in their names:
Use of 'X' as a filler

The use of 'X' as a filler letter is a practice to create three-letter identifiers when more straightforward options were unavailable:
Some airports in the United States retained their NWS codes and simply appended an X at the end. Examples include:

Airports without codes

A lot of minor airfields without scheduled passenger traffic have ICAO codes but not IATA codes, since the four letter codes allow a larger number of codes. IATA codes are mainly used for passenger services such as tickets and checked luggage, while ICAO codes are used by pilots. In the US, such airfields use FAA codes instead of ICAO.
There are airports with scheduled service for which there are ICAO codes but not IATA codes, such as Nkhotakota Airport/Tangole Airport in Malawi or Chōfu Airport in Tokyo, Japan. There are also several minor airports in Russia which lack IATA codes and instead use internal Russian codes for booking. Flights to these airports cannot be booked through the international air booking systems or have international luggage transferred there, and thus, they are booked instead through the airline or a domestic booking system. Several heliports in Greenland have three-letter codes used internally which might be IATA codes for airports in distant countries.
There are several airports with scheduled service that have not been assigned ICAO codes that do have IATA codes, especially in the U.S. For example, several airports in Alaska have scheduled commercial service, such as Stebbins and Nanwalek, which use FAA codes instead of ICAO codes.
Thus, neither system completely includes all airports with scheduled service.

Use in colloquial speech

Some airports are identified in colloquial speech by their IATA code. Examples include JFK for New York-Kennedy airport, LAX, PDX and CCU.