Do You Know the Strange Reasons For These 15 Airline Codes?

What are airline codes? Airline codes come in several types. This article is about IATA codes: two characters used in flight numbers. Take BA for British Airways, add a number, and you get a flight number like BA113. Some of these codes make perfect sense: AA for American Airlines, VJ for VietJet Air, and FC for Finncomm Airlines. Plenty of others don’t, and the reason mostly lies in how the system developed.

In the late 1940s, ICAO (the International Civil Aviation Organization) issued two-letter codes to airlines. When an airline joined IATA (the International Air Transport Association), it took that same code, so the two systems matched.

That changed in the 1980s. As the number of airlines grew, ICAO switched to three-letter codes (AAL for American Airlines, for example), and the new system became official in 1987. IATA kept its two-character format but was no longer tied to ICAO, so it assigned codes independently, and they no longer had to resemble the ICAO ones.

Two letters only give 676 combinations, so codes with numbers were introduced, such as U2 for easyJet. Often, an old code is simply passed on from a previous incarnation of the company. Codes from defunct airlines can get used again for newer airlines. Sometimes there’s a backstory to a code that doesn’t seem to make sense, though sometimes it’s just an urban legend that can’t be proven.

Here are 15 airline codes that don’t make much sense until you dig a little deeper.

Featured image credit: pexels.com/OscarChan

1. Inheritance

These IATA codes don’t make any sense because they’ve been carried over from a previous airline or company. Additionally, that previous IATA code may not have even made sense for that previous airline as it may have been randomly assigned by the IATA. Here are a few examples:

EO – Hewa Bora Airways

Hewa Bora Airways gets its IATA airline code from Congo Airlines which was founded in 1994. In 1998, it merged with Zaire Airlines and Zaire Express to form Hewa Bora Airways. Congo Airlines had been randomly assigned the code EO.

Related history: Zaire was the name of the African nation now known as the Democratic Republic of the Congo (DRC) between 1971 and 1997.

JU – Air Serbia

Air Serbia inherited its code, JU, from JAT Yugoslav Airlines (Jugoslovenski Aerotransport), where “JU” stood for Yugoslavia.

Fun fact: In February 1978, a baby was born mid-flight on JAT Yugoslav Airlines and subsequently gifted lifetime free travel on the airline. 

AY – Finnair

Finnair was originally founded in 1923 under the name Aero O/Y, later stylized as Aero Osakeyhtiö. A stands for Aero, Y stands for Yhtiö, meaning “company” or “corporation.” The airline officially changed its name to Finnair in 1968, but kept the AY code.

Fun fact: Finnair operated one of the most infamous flights ever. AY666 was a flight to HEL, Helsinki-Vantaa Airport; it stopped running in 2017.

RA – Nepal Airlines

Originally founded and known as Royal Nepal Airlines, the company held onto its earlier code of RA.

Odd detail: In 2007, Nepal Airlines sacrificed two goats on the tarmac in front of a Boeing 757 that was suffering from a persistent electrical fault. The offering was made to Akash Bhairab, the Hindu deity of sky protection, whose face is featured as the airline’s corporate logo. Apparently, the sacrifice worked. The problem disappeared and the plane left for Hong Kong immediately after the ceremony.

SN – Brussels Airlines

Brussel Airlines gets its IATA airline code from its predecessors Sabena and SN Brussels Airlines. The code first belonged to Sabena (Société Anonyme Belge d’Exploitation de la Navigation aérienne), the country’s national airline founded in 1923.

Odd detail: Brussels Airlines has featured dots for a long time, including a ‘b’ made of 13 dots. This was famously changed to 14 dots in 2007 after customer complaints that it was unlucky.

2. The Chicken & Egg Paradox

The next two airlines have IATA codes that match their names, but their names actually are based upon their call sign, in a rare switch of the usual process where an airline is assigned a code once it has formed and been registered.

S7 – S7 Airlines

S7 Airlines has quite a history: it was formed in 1992 as the state-run Siberia Airlines after the dissolution of the Soviet Union. Going back further still, it actually originates from the Tolmachevo United Air Squadron that had been established in 1957. In 1994, Sibera Airlines was privatized, and was then rebranded in 2005 as S7 Airlines, using its IATA airline code for its name. Its legal name, however remains JSC Siberia Airlines.

Fun fact: S7 planes are neon lime for a number of reasons including standing out amongst the competition, and having visibility against snowy landscapes.

KM – KM Malta Airlines

KM Malta Airlines was founded in 2023, launching in 2024, replacing the national carrier Air Malta which was shut down following years of financial losses. Air Malta’s airline code, KM, was carried over, but this isn’t just simply a case of taking a name from a predecessor, as there’s a bit more to the story. Which brings us to…

3. Urban Legends

Some of these are company lore, widely shared and accepted. Others have no proof at all and are pure urban legend, while others seem legitimate but haven’t been confirmed by the company itself. Let’s start with the KM airline code, which was just mentioned above.

KM – Air Malta

KM was the IATA airline code for Air Malta, Malta’s national carrier for 50 years. Though at first glance it seems to be totally unrelated, staff lore says that it stands for ‘Knights of Malta’ or, in Maltese, “Kavallieri ta’ Malta.”

Related history: The Knights had to pay rent for Malta to the King of Sicily: one live Maltese falcon every year on All Souls’ Day.

LS – Jet2

The popular Internet theory about the Jet2 airline code says that LS was chosen to match the first two letters of the Leeds postcode of its headquarters. This one is easily debunked though. Jet2’s IATA airline code originally belonged to Channel Express, a cargo and passenger airline founded in 1978. In 2002, Channel Express rebranded into Jet2, and the LS airline code got passed on to Jet2. For an extra bit of proof that the code isn’t related to Jet2’s Leeds headquarters, consider the timelines. Jet2 inherited the LS code in 2002 but moved to its Leeds HQ in 2006. They had previously been based in Bournemouth.

Fun fact: The registered address for J2 HQ is “Low Fare Finder House.”

FR – Ryanair

The Ryanair IATA airline code FR most likely was assigned at random, with a backronym being assigned later on. The IATA assigns airline codes based on availability when an airline registers. However, there is a popular urban legend that FR stands for “Family Ryan,” a reference to the Ryan family who founded and originally backed the airline.

Fun fact: Ryanair began as a small full-service airline, competing with carriers like Aer Lingus, then became a low-cost airline in 1994-95 under the direction of current CEO Michael O’Leary.

NK – Spirit Airlines

Same as Ryanair and FR above, NK was most likely assigned at random to Spirit Airlines, with a backronym being assigned afterwards. The theory says that NK stands for “Ned’s Kids,” referring to the way founder Ned Homfeld treated his employees. Spirit Airlines is no longer operational as of May 2026.

Fun fact: Spirit Airlines’ NYSE ticker symbol was SAVE, delisted in November 2024 after filing for Chapter 11 bankruptcy protection.

OK – Czech Airlines

There is apparently no proof either way, so take everything about the OK airline code for Czech Airlines with a pinch of salt! The most common urban legend says that while assigning codes in the mid 1940s, the Czechoslovakian representatives didn’t understand much English, and just answered “OK” to any questions. A lesser known theory states that the desired code “CS” was taken already, so the Czechoslovakian delegation had to quickly come up with an alternative. They decided on “OK” from the initials of the main delegate, Otto Kučera. And it was catchy too, so plus points on that.

Related history: In 1978, Czechoslovakia became the third country (after the Soviet Union and the United States) to send a human into outer space. Cosmonaut Vladimir Remek flew the Soyuz 28 as part of the Soviet-led Interkosmos program.

4. A Complex Family Tree

Sometimes the road to the current IATA airline code is so convoluted that it’s difficult to keep up. Yes, the code is based on the predecessor, but there’s a lot more to it than that!

HG – Niki

Niki went through quite a few owners, including two stints of ownership by Formula 1 World Champion Niki Lauda, who also founded Lauda Air. In 2003, Aero Lloyd, a German company (Code: YP), set up an Austrian subsidiary which was assigned the code HG. Niki Lauda purchased assets of this Austrian subsidiary, giving Niki the airline code HG. However, in 2017, Niki the airline was no more: it merged into Amira Air to become LaudaMotion.

Fun fact: Niki Lauda held a full commercial transport pilot’s license and regularly flew his airline’s planes as a working captain.

LX – Swiss Airlines

Contrary to popular belief, Swiss Airlines did not rebuild from Swissair (IATA airline code SR) which went bankrupt in 2002. Instead, it was formed by building around Crossair, a Swiss airline that began operating in the 1970s. The new company, officially named Swiss International Air Lines, inherited the IATA code LX from Crossair. However, it uses the three-letter ICAO code from Swissair: SWR. The ICAO code works in a similar way to the IATA code, but while the IATA code is what customers see, the ICAO code is what air traffic control see.

Related history: The original Swissair was known as “The Flying Bank” because it was so profitable and was considered an a symbol of wealth and safety. This made its bankruptcy even more shocking.

MX – Breeze Airways

Breeze Airways was founded in 2018 by David Neeleman under the name Moxy Airways, because according to him launching an airline takes moxie. However the name was changed to Breeze Airways in 2020 so as to avoid confusion with the Marriott’s Moxy Hotels trademark. The airline officially launched in 2021, but carried over its IATA airline code MX.

Related history: The MX code had previously belonged to the now-defunct carrier Mexicana de Aviación before being reassigned to Breeze.