Are IATA & ICAO Airline & Airport Codes Interchangeable?

Is it possible to use IATA and ICAO airline search codes interchangeably?

In Europe the airlines appear to predominately use IATA codes. However the main airline we use is ICAO. However, we need to use both.

SWR = LX - SWISS (IATA)

BAW = BA (IATA)

U2 = EasyJet (IATA)

EZY = EasyJet (ICAO)

LSGG = GVA (IATA)

Is this possible? If so could you please explain how.

Thank you in advance.

Simon.

Most FlightXML functions will accept either ICAO or IATA, but we recommend passing ICAO identifiers to us when possible because there are ambiguities that prevent us from being able to always handle all IATA codes. In particular, airline codes that have numerals in their IATA identifiers (JetBlue, EasyJet, etc) will generally not be handled. Results are always returned in ICAO format.

Thank you for your reply.

What about LX (SWISS), BA and GVA which do not have numerals in their identifiers?

You can try it and see if those work. However, as I mentioned before we do not officially recommend that you design your application to be dependent upon the server-side IATA conversion being reliable.

Be aware that if you have “position-only flights” enabled in your account’s website preferences, that will disable the automatic IATA conversions.

Thank you for your help