How do Airlines Create Flight Numbers?

Michael Pollick
Michael Pollick

While many flight numbers may appear random, there is definitely a method behind the madness. Individual airlines create their own numbers based on internal methodology, but they must coordinate their efforts with other airlines in order to avoid confusion in the flight control towers. United Airlines and American Airlines, for example, cannot both have two incoming planes with similar flight numbers arriving at the same time. Airlines are governed by the International Air Transport Association (IATA), and it often falls on the IATA to approve these designations before they can be implemented by an airline.

Airlines are governed by the International Air Transport Association, which ultimately signs off on flight numbers.
Airlines are governed by the International Air Transport Association, which ultimately signs off on flight numbers.

Many flight numbers are assigned according to the general direction of the flight itself. Planes headed east or north are usually assigned even numbers, while planes headed west or south are assigned odd ones. Return flights are often assigned those that are one number higher than the departure flight, so passengers can easily remember which return flight to take. For example, the fictional WiseGEEK Airlines may have a flight from New York to Las Vegas departing at noon. Since it is traveling west, it may be designated as flight 711. The WiseGEEK Airlines flight from Las Vegas back to New York would most likely be called flight 712. Both flight numbers would have to be approved by the IATA, in case there happened to be an existing United Airlines flight 712 also arriving in New York at about that time.

Airlines assign flight numbers that adhere to agreed-upon guidelines.
Airlines assign flight numbers that adhere to agreed-upon guidelines.

Airlines also assign flight numbers according to a set of agreed-upon parameters. One major airline may agree to limit its possible choices to 1-499. Another airline, possibly a smaller carrier working with the major airline, could have 500-749. Another major airline may have numbers from 750-1000, and so on. Through a practice called code sharing, smaller regional airlines working together with major airlines coordinate their numbers to avoid confusion and to designate the flight as a joint effort. Some airlines also designate flight numbers according to the destination of the plane or the type of passengers it will carry. Domestic flights, for example, may have two digit numbers while international flights may have three digits. This practice varies from airline to airline, but they are usually consistent. Chartered flights may have special numbers that instantly allow airline employees to recognize them.

Assigning flight numbers isn't all business, however. Airlines are allowed, within reason, to designate planes with significant or whimsical numbers. A flight to San Francisco, for instance, may receive one such as 49 or 1849 as an homage to the famous Gold Rush of 1849. An airline providing service to Philadelphia might select 1776 or 76, reflecting that city's historical role in the formation of the United States. Some flights to casino towns like Las Vegas or Reno, Nevada could have numbers with 7s and 11s for luck. As long as the airline does not violate IATA regulations concerning flight numbers, it can select numbers for reasons of its own. These numbers can also be changed if they become controversial, as in the case of American Airlines Flight 11, which crashed into the World Trade Center on 11 September 2001. When commercial flying privileges were restored, the airline changed Flight 11 to Flight 25.

Michael Pollick
Michael Pollick

A regular wiseGEEK contributor, Michael enjoys doing research in order to satisfy his wide-ranging curiosity about a variety of arcane topics. Before becoming a professional writer, Michael worked as an English tutor, poet, voice-over artist, and DJ.

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Discussion Comments


@anon82382: he said North and East flights are even, and West/South flights are odd, thus validating WGK711 to Vegas, and 712 back again.


Another trend has been to retain the same flight number despite stopping at more than one port. The benefit to the airline is that it reduces the point-to-point miles and status credits it needs to award than would otherwise be necessary for the same two-stop routing that would ordinarily have involved two separate flight numbers.


nice article but i will disagree on one point:

You sat that N/S flights are even numbers.. but your LAS flight to JFK/LGA/EWR is even. i know that it is a returning flight but this contradicts what you just said about the N/S numbers.

It is sometimes the case but i just want to point out the contradiction.

Take it from someone who knows:

Flight numbers are generally (99 percent) based on the the type of flight.

Take US Airways for example:

their Caribbean - CLT (Charlotte) flights are usually AWE 14XX or AWE 15XX

Usually regional affiliates are numbers ~2XXX - ~4XXX

One exception is PSA Air ("bluestreak") flights opperating on behalf os US Airways Express... these are usually triple digit (but they use the Callsign BlueStreak as opposed to Cactus which is used by US Airways).

Also Delta's DC-9 (30/50 series) are numbers 79XX

numbers 8XXX are usually charter.

numbers 9XXX are usually repositioning or training

numbers in the double-digits (especially lower than 10) are the carrier's "flagship" flights:

Jet Blue flight 1 is fron New York (JKF their hub) to Ft. Lauderdale (also their hub).

Also triple digit/lower numbers are more than likley (if not "flagship") trans-continental:

US Airways 732 is from CLT to LGW (london-Gatwick)

Nice article but i had to post this.


Whimsical indeed. Before the cutback in flight count, there was a direct flight from Denver to Columbus: 1492.

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