I found on this website several questions speaking of IATA, ICAO and airports codes. The fact that two identification codes for the same airport exist means there are cases where you use one, and other cases where you use the other. I wonder what is the rule to know which code (IATA or ICAO) should be used.

  • $\begingroup$ Related: aviation.stackexchange.com/questions/8699/… $\endgroup$ Commented Mar 9, 2016 at 5:58
  • $\begingroup$ You may book a ticket with a travel agency to DLP, which is the IATA code for Disneyland in Paris suburb. However there is no ICAO code associated, because the park has no aeronautical activity and is not even close to an airport. $\endgroup$
    – mins
    Commented Jun 23, 2021 at 14:41

1 Answer 1


It helps to know the objective of both ICAO and IATA to understand when which code is used.

ICAO (International Civil Aviation Organization) is a UN-body which focusses on international harmonization of civil aviation regulations.

ICAO codes are used for "official" purposes such as Air Traffic Control; E.g. flight plans use ICAO codes for airports and airline flight identification.

IATA (International Air Transport Association) is a trade association that focusses on making air traffic businesses profitable, safe, secure, reliable and efficient.

IATA codes are mainly used for ticketing. E.g. travel itineraries use IATA codes for airports and IATA flight numbers.

  • 2
    $\begingroup$ The IATA codes are 3-letter codes, since the number of commercial airports worldwide is enough that 3 letters are enough: DFW, LHR, NRT, etc. The ICAO codes cover more airports, so they're 4 characters with the first (USA) or first two (most of the rest of the world) describing the region, and the last two unique to the airport there: DFW (IATA) = KDFW (ICAO) {K=USA}, LHR (IATA) = EGLL (ICAO) {since EG = Europe/Great Britain), and NRT = RJAA (RJ = East Asia/Japan). Your ticket might say DFW-LHR, but flightplan is filed KDFW-EGLL. $\endgroup$
    – Ralph J
    Commented Aug 1, 2015 at 16:36
  • $\begingroup$ While pretty much all airports has an ICAO code, many smaller and non-serviced ones does not have an IATA. For example, look at small, unusual, high altitude airports. Basically, if they are marked on a flight map, it probably has an ICAO.With the obvious exception of countries/territories not conforming to int'l standards/rules. $\endgroup$
    – not2qubit
    Commented Feb 6, 2018 at 21:20
  • $\begingroup$ I don't buy this "different codes for different purposes" explanation. Both assign codes to the same things so this just seems like pointless and confusing duplication. $\endgroup$
    – xjcl
    Commented Mar 29, 2019 at 18:42
  • $\begingroup$ @xjcl You don't have to buy it, but isn't it very common to have multiple codes for the same thing? this, 40885, 02102, Lintorf, 8RQM+VM; all these are codes for the city you are from according to your profile. $\endgroup$
    – DeltaLima
    Commented Apr 16, 2019 at 7:47
  • $\begingroup$ Of note, in the USA: Terminal-area air traffic controllers prefer the FAA Location ID rather than the ICAO code. For airports with an IATA code, the FAA LID is usually (though not always) the same as the IATA code. $\endgroup$
    – randomhead
    Commented Apr 24, 2021 at 4:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .