What IATA and ICAO Aiport Codes Work For?

Have you ever noticed that the air ticket you purchase has some codes listed on it? Let’s suppose you’re flying from San-Francisco to Milano, your ticket will have the SFO-MXP letters printed, without any doubts.

Keeping up with all the air flight terminology is not mandatory for a passenger, as there’s so much more to take care of, before, during and after the flight. But, just in case you’d like to delve more into this subject and discover the secret behind the bolded letters, here’s our IATA and ICAO codes blog post to help you out.

About IATA Codes

The codes that we provided as an example are none other than IATA airline codes. IATA is an abbreviation for the International Air Transport Association, which is an international airline industry trade group, that works under 260 airlines from over 117 nations. Its purpose is to define policy and standards in the industry and to support airlines’ activity. It also has the duty to set the prices and to help its customers receive safe and secure transits.

To keep the tracking and electronic application process simple and hassle-free, for both customers and airlines, IATA implemented a code system. It was divided into two types: airline codes (also known as airline designators or IATA reservation codes) and airport codes.

Airline designators are two-letter codes that are assigned to any airline. You can take a look at them in IATA Airline Coding Directory that is published two times annually. They follow the XX(A) format and consist of two alphanumeric characters (digits and letters), succeeded by a letter as an option.

Despite the fact that three-letter designators are provided by IATA standard, the optional letter was never used by it. This can be explained by the fact that some computer systems, "central reservation systems" in particular, could not comply with the standard. The current code system complies with IATA Resolution 762, which supports only 2-letter codes.

The question is, how these codes work for you? What benefits can you get from knowing these codes? The answer is that you can find IATA airline designators on timetables and tickets. When you make a ticket reservation, these are imprinted on waybills. These codes are used in telecommunications, as well. On that account, it is an efficient and quick way to identify the airline you are flying with.

IATA airport codes, on the other hand, consist of three letters. Altogether, these letters create a code that designates a great number of airports and metropolitan areas across the planet. Taking into consideration the fact that these codes indicate a location, they are also named as location identifiers. These are the most used codes, and you probably saw them, as they are showed boldly on baggage tags, which are attached to your luggage at the check-in desks.

To show you the difference between IATA airport codes and airline codes, we revealed the busiest airports in the world, the airlines that are connected to those airports, as well as their IATA codes, in the below table.

For the further discovery of both IATA airline and airport codes visit iata.org. By entering the code in the search bar, you can find both IATA 3-letter city codes, airport codes, as well as airline codes, to be able to identify the full name of the respective location or airline.

About ICAO Codes

As we cleared up the topic about IATA codes, we can move on to other code types that are used in the coding system - ICAO codes. ICAO is a governmental institution that provides recommendations for better practices concerning air transport. It also adopts standards, and guides air infrastructure, facilitates border-crossing procedures for international civil aviation, and prevents unlawful interference.

The International Civil Aviation Organization formulates guidelines for the United Nation countries, for better interaction between them in the aviation industry. For this purpose, it implemented codes that work within 192 member states. Just like IATA, ICAO uses airline and airport codes to make the flight planning process more efficient.

If IATA uses its codes on tickets and baggage tags, ICAO codes are used mostly among airlines and airports. Regularly, air passengers can see ICAO codes on flight-tracking services. That doesn’t make them less important, and thus, people can be informed of them as well. For this very reason, you should know that there are two types of ICAO codes, just like IATA. 3-letter codes are used for airlines and 4-letter codes - for airports.

ICAO 4-letter codes are distributed according to the region and the country, therefore the first, or the first two letters, of the airport code indicate the corresponding name of the region and country. For instance, EGLL for London Heathrow Airport, where EG is the corresponding prefix code for Northern Europe, and the United Kingdom. CYHM for Hamilton/John C. Munro International Airport, where the prefix code C stands for Canada.

ICAO airline codes consist of three letters and serve the same purpose as IATA airline designators - to track the airline, and to simplify the identification process.

To ease the explanation, here is a table that contains both ICAO airline and airport codes, for the same airlines and airports used in the table above.

IATA and ICAO codes date back to the 1930s and 1974, respectively. Initially, IATA was the one to use airport codes. Pilots from the US used two-letter codes from the National Weather Service (NWS) to identify cities. As not every city had an NWS identifier, it was not possible to track all the cities, thus a three-letter code system was implemented. This system was a convenient one, as it could identify a great number of airports, and it allowed doing 17,576 letter combinations.

On the other hand, ICAO airport codes have been consisting of 4 letters. This dates to the present day. Their airport codes were based on radio station identifiers, back then. Therefore, the radio station of a specific location, for example, Canada, was starting with a letter or a combination of two letters ("C", in this particular case). As a result, the code was having a Cxxx format.

Talking about airline codes, ICAO, which was established, by the way, in 1947, implemented for the first time 2-letter codes to designate airlines. In the early 1950s, IATA took over ICAO codes, which caused the last one to change its codes to a 3-letter format. Beginning with 1988, ICAO airline codes had a 3-letter format officially, and IATA used 2-letter codes to designate airlines, instead.

Generally speaking, IATA codes and ICAO codes have the purpose to implement standards and practices, in both airport and airline activities. This thing is supposed to ensure their customers’ safety, as well as to make air navigation more efficient. Now you can tell the difference between IATA and ICAO codes.

What's more, now you don't have to question yourself about what is that London Heathrow three letter code, Beijing 3-letter code, or Atlanta Airport 3-letter code on your flight ticket.

Last Updated on September 5, 2019.