Random IATA Airport Code

How this random airport code generator works

Press Generate and you get an airport and its three-letter code. Turn up the Number box for several at once, no repeats. Copy takes them. Everything runs in your browser.

Amsterdam Schiphol AMS. Cape Town CPT. Delhi DEL. Doha DOH. Istanbul IST. Kathmandu KTM. Lima LIM. Nairobi NBO. Reykjavik KEF. Zurich ZRH.

Those three letters look like an abbreviation. Some of them are. A surprising number are the fossilised name of something that stopped existing seventy years ago.

Three letters for you, four for the pilot

Two entirely separate coding systems run over the same airports, and most travellers never notice the second one.

IATA codes are three letters. They come from the International Air Transport Association, which is a trade body for airlines. These are the codes on your boarding pass, your baggage tag, and your booking confirmation.

ICAO codes are four letters. They come from the International Civil Aviation Organization, a United Nations agency. These are the codes pilots file flight plans with and air traffic controllers speak out loud.

The difference is not just length. IATA codes are handed out to be memorable. ICAO codes are handed out to be geographic. In an ICAO code the first letter is a region and the second is a country, so EG is the United Kingdom and EGLL is Heathrow, which is LHR to you.

One system is designed so a passenger can find their gate. The other is designed so that no two people on a radio can possibly misunderstand each other. The second job is more important, which is why it gets an extra letter.

Airport codes are fossils

Once assigned, an IATA code almost never changes. Airports get renamed, cities get renamed, the reason for the letters disappears, and the code stays. So the code becomes the last surviving trace of a name nobody uses.

• ORD is Chicago O'Hare. The airfield was called Orchard Place. It was renamed in 1949 after a Medal of Honor recipient. Nobody changed the code.
• MCO is Orlando. It stands for McCoy Air Force Base, which is what was there before.
• EWR is Newark. It could not be NEW, because the United States Navy had reserved every code beginning with N. So Newark took the other letters out of its own name.
• LAX is Los Angeles. Under the old two-letter system it was simply LA. When three letters became compulsory, an X was tacked on as a placeholder. A great many X's in airport codes are exactly that: filler.
• PEK is Beijing. It preserves Peking, the older romanisation of the city's name, frozen at the moment the code was issued.

Read enough of them and the codes stop being a lookup table and start being an archaeological record of what places used to be called.

Why almost every Canadian airport starts with Y

YYZ. YVR. YUL. YYC. Toronto, Vancouver, Montreal, Calgary. Not one of those letters looks like the city it serves.

The explanation goes back to radio. Before airports had their own codes, weather and radio stations carried two-letter identifiers, and Canadian airfields borrowed them. When codes went to three letters, Canada put a Y on the front of the pair it already had.

Toronto Pearson sits at Malton, whose station identifier was YZ. Put the Y in front and you get YYZ, which is also, for reasons of Canadian pride, the title of a Rush instrumental.

You will read in a lot of places that the Y stood for "yes, there is a radio station here". It is a good story. No source for it traces back to anybody who was in the room, so treat it as folklore until somebody produces the memo.

There are only 17,576 of them

Three letters, twenty-six options each. Twenty-six cubed is 17,576. That is every code that will ever exist, and IATA has been handing them out since the 1930s.

Which is why the obvious ones ran out and airports started getting strange ones. When the code you want is taken, you take an alternative spelling, a historical name, or whatever three letters are left.

Sometimes what is left is unfortunate. Sioux Gateway Airport in Iowa was assigned SUX. It petitioned to have the code changed, twice. It was told no. It now sells merchandise reading "Fly SUX", which is the correct response.

Derby Field in Lovelock, Nevada, has the code LOL, assigned long before that meant anything.

A three-letter namespace is a harder engineering problem than it looks, and the airports living inside it have no way out.

Not everything with an airport code is an airport

IATA's own Airport and Location Identifier Database covers roughly 12,000 locations. Not 12,000 airports.

The register includes metropolitan areas, rail stations, bus stations, ferry ports and heliports. If a train can carry your luggage on a through ticket, it needs a code, because the ticket does not know the difference between a platform and a gate.

This is why a code you have never seen may be a station in Switzerland, and why a code you assume is an airport may be a whole city. LON is London, all of it. LHR, LGW, LCY, STN and LTN are the airports inside it.

Once you know that, the three letters stop meaning "airport" and start meaning "a place a journey can be sold to", which is a much odder and more useful idea.

Ways people actually use this

• Aviation quizzes. Show the code, ask for the airport. ORD and MCO will finish most people.
• Testing booking systems. Real codes for real airports, which is what your validation actually wants to see.
• Deciding where to fly. Not seriously. But if you have air miles and no plan, generating three destinations is a better shortlist than staring at a map.
• Learning the codes you keep forgetting. Generate ten a day. Within a month you will read a departures board differently.
• Writing. A boarding pass in a story needs a real code on it, or somebody will notice.

Getting more out of the filters

• Ends with reads the last character, which for every entry is the last letter of the code. Set it to X and most of what comes back has an X only because somebody needed a third letter.
• Type a code straight into Contains. Typing KTM finds Kathmandu. Typing International finds most of the list, which tells you something about how airports name themselves.
• Type Y into Contains alongside a Canadian city and the pattern from the section above will jump out at you.
• If a filter returns fewer airports than you asked for, loosen it and run again.

Questions people ask

What is the difference between IATA and ICAO codes?

IATA codes are three letters, used for tickets and baggage. ICAO codes are four letters, used for flight plans and air traffic control. The same airport has both. Heathrow is LHR and EGLL.

Why is Chicago O'Hare called ORD?

Because the airfield was called Orchard Place before it was renamed after Butch O'Hare in 1949. The name changed, the code did not.

Can an airport change its code?

Almost never. Codes are treated as permanent because too much software depends on them. Airports that dislike their code, like Sioux City with SUX, usually end up keeping it.

How many airport codes are there?

IATA's register covers around 12,000 locations, including rail and bus stations that connect to flights. The theoretical maximum is 17,576, because there are only that many three-letter combinations.

Why do so many codes end in X?

When two-letter codes became three-letter codes, many airports simply added an X to fill the gap. LAX was LA. It means nothing at all.

References

1. IATA code search
2. Airport and Location Identifier Database, IATA
3. IATA codes