What is a flight number?

A flight number is a unique universal code for an airline’s flight, consisting of a two-character airline abbreviation and a one- to four-digit number.

Flight numbers are used to identify specific flights with ease.

What are flight numbers used for?

They are used within the aviation industry to identify each flight.

Because many airlines fly the same route multiple times per day, trying to identify a specific flight based on the route is not effective.

For example, American Airlines flies from Miami to Chicago up to 9 times per day. It’s a lot easier to identify a specific flight by referencing it as flight AA2203.

What do the numbers mean?

Although there is no uniform rule, most airlines follow the same three trends when deciding which numbers to allocate to a flight.

1. Even flight numbers are typically assigned to north and eastbound flights while south and westbound flights end in odd numbers.
2. Airlines usually assign the return (back to its hub) flight number as only a digit higher than the outbound flight.
3. The airline’s most important/valued routes will have the lowest flight numbers, for example Delta’s DL1 is a flight from New York to London.