IATA and ICAO codes explained: decoding airports, airlines and aircraft types

The baggage tag says FRA, the flight tracker says EDDF. The Lufthansa aircraft is LH on the display board and DLH on the live map. And the jet at the fence is sometimes a 77W, sometimes a B77W. Anyone who deals with aircraft constantly stumbles over two parallel code worlds. This guide shows you what separates IATA and ICAO codes, how they are built and where you run into which one while spotting – so you can immediately place airports, airlines and aircraft types in any app and any report.

IATA and ICAO: the short answer

Behind the two abbreviations are two different organizations with different tasks. IATA (International Air Transport Association) is the worldwide association of airlines. Its codes are meant for the commercial side of aviation: ticket sales, baggage sorting, schedules, display boards. ICAO (International Civil Aviation Organization) is a specialized agency of the United Nations. Its codes serve flight operations: air traffic control, flight planning, weather reports, navigation.

The result is three pairs of codes that you run into again and again:

Rule of thumb: everything you see as a passenger is usually IATA. Everything that controllers, pilots and weather services use is usually ICAO. Flight trackers and spotter apps mix both – which is why it pays to know both systems.

Area	IATA	ICAO	Where you see it
Airport	3 letters, e.g. MUC	4 letters, e.g. EDDM	IATA on boarding pass and baggage, ICAO in METAR and flight plan
Airline	2 characters, e.g. LX	3 letters, e.g. SWR	IATA in the flight number, ICAO in the callsign
Aircraft type	3 characters, e.g. 359	up to 4 characters, e.g. A359	IATA in the airline’s schedule, ICAO on trackers

IATA airport codes: three letters for the travel world

IATA assigns its airport codes through its headquarters in Montreal under an association-internal resolution. Every code consists of three letters and is unique worldwide. A few examples from Germany:

• Frankfurt: FRA
• Munich: MUC
• Düsseldorf: DUS
• Hamburg: HAM
• Berlin Brandenburg: BER
• Leipzig/Halle: LEJ
• Hanover: HAJ

Many codes are obvious, some seem puzzling. The reason: a code, once assigned, is rarely changed. It often stays even when the name of the airport or even the city changes. Chicago O’Hare is ORD because the site used to be called Orchard Field. You still fly to Ho Chi Minh City under SGN – after the old name Saigon. And Los Angeles became LAX because, when the codes were switched to three letters, an X was added as a filler to the older identifier LA.

A special case are Canadian airports, almost all of which begin with Y: Toronto YYZ, Vancouver YVR, Montreal YUL. The Y comes from an old identifier system for weather and radio stations in which it marked a site with an airfield.

City codes for metropolises with several airports

For cities with several airports, there are also metropolitan codes. LON combines the London airports, including Heathrow (LHR), Gatwick (LGW) and Stansted (STN). PAR stands for Paris with Charles de Gaulle (CDG) and Orly (ORY), NYC for New York with JFK, LaGuardia (LGA) and Newark (EWR). In booking systems, this lets you search for all airports of a city at the same time.

Berlin shows how this shifts over time: the former airports Tegel (TXL) and Tempelhof (THF) are closed, and Schönefeld (SXF) has been absorbed into the new airport. Today Berlin’s traffic runs under BER, the code of Berlin Brandenburg Airport.

ICAO airport codes: four letters with a system

ICAO location indicators are built differently. They are published in ICAO Document 7910 (Location Indicators), and the individual states are involved in choosing the codes. Four letters, and the first ones tell you the region:

• First letter: Large region. E stands for Northern and Central Europe, L for Southern Europe and parts of the Mediterranean, K for the USA excluding Alaska and Hawaii, C for Canada, Y for Australia, Z for China, among others.
• Second letter: In Europe usually the country. ED stands for civil airfields in Germany, ET for military ones. LS is Switzerland, LO Austria, EH the Netherlands, EG the United Kingdom, LF France.
• Third and fourth letters: The individual airfield. For the big German commercial airports, the code almost always begins with EDD.

Airport	IATA	ICAO
Frankfurt	FRA	EDDF
Munich	MUC	EDDM
Düsseldorf	DUS	EDDL
Hamburg	HAM	EDDH
Berlin Brandenburg	BER	EDDB
Cologne/Bonn	CGN	EDDK
Stuttgart	STR	EDDS
Leipzig/Halle	LEJ	EDDP
Hanover	HAJ	EDDV
Nuremberg	NUE	EDDN
Zurich	ZRH	LSZH
Vienna	VIE	LOWW
Amsterdam Schiphol	AMS	EHAM
London Heathrow	LHR	EGLL
Paris Charles de Gaulle	CDG	LFPG

In the USA and Canada, the system is particularly convenient: there the ICAO code often simply results from the IATA code with a region letter in front. JFK becomes KJFK, LAX becomes KLAX, YYZ becomes CYYZ. In Europe this trick doesn’t work – FRA and EDDF have nothing to do with each other.

The ICAO code matters to you mainly for weather reports. METAR and TAF are always retrieved with the four-letter location indicator. If you want to check in the morning whether it will be windy in Munich, you search for EDDM, not MUC. How to read the reports is explained in the guide Reading METAR and TAF.

Airline codes: LH, DLH and the radio callsign

Airlines also carry two codes. The IATA code has two characters – letters, digits or a mix – and forms the start of every flight number as it appears on tickets and display boards. The ICAO code consists of three letters and is tied to a radio callsign (telephony designator) with which the crew identifies itself on the radio. The ICAO designators are listed in ICAO Document 8585. ICAO introduced the three-letter system in the 1980s, while IATA stuck with its two-character codes.

Airline	IATA	ICAO	Radio callsign
Lufthansa	LH	DLH	LUFTHANSA
Eurowings	EW	EWG	EUROWINGS
Condor	DE	CFG	CONDOR
SWISS	LX	SWR	SWISS
Austrian Airlines	OS	AUA	AUSTRIAN
Emirates	EK	UAE	EMIRATES
Ryanair	FR	RYR	RYANAIR

For some airlines, the radio callsign has a history of its own. British Airways identifies itself as SPEEDBIRD, a legacy of its predecessor BOAC. For you at the radio scanner, that means: not every callsign sounds like the airline name. What the law says about listening in is in the article Listening to aviation radio: the legal situation.

Why IATA codes don’t always fit

Two-character codes are scarce. IATA therefore reassigns codes after a waiting period once an airline ceases operations, and it knows so-called controlled duplicates: two airlines whose route networks practically don’t overlap share the same code. On top of that, codes are usually kept when names change. That is why they often don’t match today’s name – Finnair, for example, flies under AY, Icelandair under FI. ICAO codes, on the other hand, are unique, which makes them more reliable for air traffic control and data analysis.

Flight number and callsign are connected

The departure board says LH 400, on the flight tracker you see DLH400. That is not a contradiction: flight trackers show the callsign that the transponder transmits, and it begins with the airline’s ICAO code. However, the flight identifier in the callsign isn’t always identical to the commercial flight number – some airlines use alphanumeric identifiers to avoid confusion on the radio. The details are explained in the article Callsign and flight number: the difference. With codeshare flights, several IATA flight numbers are also added for the same flight, for example within the Star Alliance – the callsign always stays that of the operating airline.

Aircraft types: 77W, B77W and the rest

At the fence it gets especially exciting for spotters, because aircraft types also have two codes. The ICAO type designator has two to four characters and is in ICAO Document 8643 (Aircraft Type Designators). It is used by air traffic control and in flight planning. The IATA type code has three characters, comes from airline scheduling and distinguishes types more by commercial features such as role or version.

Aircraft type	IATA	ICAO
Airbus A320neo	32N	A20N
Airbus A321neo	32Q	A21N
Airbus A350-900	359	A359
Airbus A350-1000	351	A35K
Airbus A380-800	388	A388
Airbus A220-300	223	BCS3
Boeing 737-800	738	B738
Boeing 737 MAX 8	7M8	B38M
Boeing 777-300ER	77W	B77W
Boeing 787-9	789	B789
Boeing 747-8	74H (passenger) / 74N (freighter)	B748
Embraer E190	E90	E190
Dash 8-400	DH4	DH8D
Bombardier CRJ900	CR9	CRJ9

A few patterns stand out. For Boeing, ICAO puts a B in front (B738, B789), for Airbus an A (A359, A388). Some codes are relics, though: the A220-300 runs at ICAO as BCS3, because it was developed as the Bombardier CSeries CS300. And on the 747-8 you see the different logic: IATA separates the passenger and freighter versions, ICAO doesn’t – its designators don’t distinguish between passenger or cargo use of the same type.

For you, that means: if a tracker shows “A20N,” you know an A320neo is coming and not a classic A320. How to tell the two apart at the fence even without a code is shown in the guides Identifying aircraft types for beginners and Telling Airbus and Boeing apart.

Where you run into which code while spotting

In everyday use, you constantly switch between both systems. This overview helps with sorting them:

A made-up but typical example: you’re standing at the Zeppelinheim viewing platform and see “UAE45 – A388 – OMDB → EDDF” on the tracker. Translated, that means: Emirates (UAE), an Airbus A380-800 (A388), en route from Dubai (ICAO OMDB, IATA DXB) to Frankfurt (EDDF, FRA). If you can read the codes, you don’t need three clicks to know whether the wait is worth it.

Typical mix-ups

• Mixing up airport and airline codes: LH is Lufthansa, LHR is Heathrow. Two characters usually mean airline, three mean airport – at ICAO accordingly three for airline, four for airport.
• Treating the ICAO type code as the model name: A320 is the classic A320, A20N the A320neo. If you log both as “A320,” you lose information.
• Guessing codes from the name: Hanover is HAJ, not HAN. Nuremberg is NUE, Leipzig/Halle LEJ. When in doubt, look it up instead of guessing.
• Assuming ICAO and IATA are related: In North America often yes (KJFK/JFK), in Europe practically never (EDDM/MUC).
• Equating flight number and callsign: The flight identifier in the callsign can differ from the flight number sold. For searching on the live map, the callsign is more reliable.

Conclusion

IATA and ICAO codes aren’t competing systems but two tools for different jobs. IATA serves the travel world with short, memorable codes: three letters for airports, two characters for airlines, three for aircraft types. ICAO serves flight operations with systematic, unambiguous designators: four letters for airports with a regional prefix, three for airlines together with a radio callsign and up to four for aircraft types. If you can read both, you find flights faster, understand weather reports and document sightings unambiguously. A good way in: learn the codes of your home airport and of the five airlines you see there most often – the rest comes with every spotting day. If you’re just starting out, the guide Plane spotting for beginners also helps.