Interesting facts
about flight number

  • Flight codes have changed significantly over time. Before the 1960s, flight numbers were often just one or two digits. As air travel grew exponentially, so did the length and complexity of flight numbers.
  • While there are certain common practices, there isn’t a standard global system for flight number assignment. Individual airlines have their own policies, leading to a lot of variation.
  • Superstition can play a role in flight number assignments. For instance, the number “13” is often avoided due to its association with bad luck, and the number “666” is skipped because of its negative connotations.
  • Retired flight numbers: Airlines often retire flight numbers associated with accidents or tragedies, such as Malaysia Airlines’ MH370, to show respect for the victims and their families.
  • For many airlines, particularly in the United States, a four-digit flight number starting with a ‘3’ or higher often indicates a codeshare flight operated by a partner airline.
  • The flight with the highest number is ‘9Y9999’ of EasyFly, while ‘AA1’ of American Airlines is among the shortest.

Learn more

Why do airlines use flight numbers?

Airlines use flight numbers to identify and track their flights.

With thousands of aircraft crisscrossing the skies every day, flight numbers provide an efficient way to track, manage, and coordinate flights on a global scale. They ensure that each flight is easily distinguishable, thus mitigating any potential confusion in busy airspaces and airports.

Flight numbers making life easier for passengers, airline staff, and air traffic control. This system simplifies ticketing, scheduling, baggage handling, and overall flight operations. Using flight numbers ensures a streamlined experience for everyone involved in air travel.

How are flight numbers assigned?

Flight numbers are assigned by airlines. There is no standard system for assigning flight numbers, so each airline has its own unique system.

Airlines may also use different numbering schemes to distinguish between various types of services or aircraft, such as non-stop flights or code-shared flights with partner airlines.

Flight number format explained

Flight numbers are typically composed of two parts: the airline's two-letter IATA code and a number. The numerical portion usually ranges from 1 to 4 digits, with higher numbers often indicating regional or less prominent routes.

Often, flight numbers correlate with the route, time, and direction of the flight. For instance, eastbound or northbound flights may have even numbers, while westbound or southbound flights have odd numbers.

For example, the flight numbers for an Emirates flight from Dubai to Frankfurt are:

  • EK 43, departing 03:45
  • EK 45, departing 08:25
  • EK 47, departing 15:20

while the "return" flights (from Frankfurt to Dubai) are indicated as:

  • EK 44, departing 11:00
  • EK 46, departing 15:15
  • EK 48, departing 22:20

Some airlines use letters instead of numbers in their flight numbers, or even special characters such as hyphens or underscores. Occasionally, one or two-letter suffixes may be attached at the end of the flight number (e.g., flight DL100A). These are often used to denote special circumstances, such as the use of an alternate aircraft, or flights that are part of a code-share agreement with other airlines.

Examples of flight numbers for popular routes

Popular routes often have memorable or lower flight numbers. For example:

  • British Airways Flight BA1: This prestigious flight number was previously assigned to British Airways' flagship Concorde service from London to New York. Today, it's a business class-only flight from London City Airport LCY to John F. Kennedy International Airport JFK in New York.
  • Qantas Flight QF1: Qantas reserves its lowest number for its flagship route from Sydney SYD to London LHR via Singapore SIN, emphasizing its prestige.
  • Air France Flight AF666: This flight number, incorporating '666' often associated with superstition, intriguingly operates from Paris CDG to Helsinki HEL (notice the airport code!).
  • Cathay Pacific Flight CX888: Catering to numerology favored in some Asian cultures (the number 8 is considered lucky), this flight connects Vancouver International Airport YVR, Canada, to Hong Kong International Airport HKG
  • Delta Air Lines Flight DL888: Similarly, Delta reserves this flight number for the busy route between Beijing PEK and Los Angeles LAX, showing cultural sensitivity.
  • American Airlines Flight AA100: Popular route that connects John F. Kennedy International Airport JFK, New York, to London Heathrow Airport LHR.

How to find flight number on a ticket or reservation?

To find your flight number, check your ticket, e-ticket, or reservation confirmation email. The flight number is usually displayed prominently near the airline name, departure and arrival airports, and departure time (usually near the top of the page).

On a physical ticket, it might be printed near the top or in the center, while in an e-ticket or email, it's often included in the flight details section.

How to find flight number on a boarding pass?

To locate your flight number on a boarding pass, look for a combination of the airline's two-letter IATA code followed by a series of numbers. The flight number is typically displayed prominently, either near the top or in the center of the boarding pass.

It will usually be positioned close to the airline name, departure and arrival airports, and departure time.

Do flight numbers change for the same route on different days?

In most instances, airlines maintain consistency in their flight numbers, meaning that a specific flight number generally denotes the same route regardless of the day.

Using consistent flight numbers for daily or regularly scheduled flights helps minimizing confusion for passengers and staff. In cases where the same route has multiple daily flights, the airline may assign different flight numbers to each departure, which remain consistent across days.

However, there are exceptions where flight numbers can indeed change for the same route on different days, largely due to such factors as day of operation (flights that don't operate daily may have different flight numbers based on the day of the week), seasonal changes (a flight number used for a route in summer may not be the same in winter), and higher demand (additional flights on the same route may have different flight numbers).

Do codeshare flights have different flight numbers for the same flight?

Yes, if airlines have a code-share agreement (where two or more airlines share the same flight), the same physical flight will have different flight numbers under each airline.

When booking a codeshare flight, you may see multiple flight numbers for the same flight, each corresponding to a different airline participating in the codeshare.

For example:

Airline A and Airline B have a code-share agreement for a flight from New York JFK to London LHR. When Airline A sells tickets for this flight, it might be listed as "Airline A Flight AA101", while the same flight sold by Airline B might be "Airline B Flight BB202".

Both "AA101" and "BB202" are the same flight, operated by either Airline A or Airline B, but marketed and sold by both. Passengers from both airlines will be on the same aircraft.

What are the websites for searching flight numbers?

There are several reliable online platforms where you can search for flight numbers, track flights, and gather related information:

  • FlightStats: Provides real-time flight status, tracking, and historical performance data for most flights worldwide.
  • FlightAware: Free flight tracking services, along with other aviation data. It offers real-time flight data, airport delays, and weather maps.
  • FlightRadar24: Real-time aircraft flight tracking, on a map-based interface.

You can also find flight numbers on airline websites.

Quick tip: Simply typing the flight number into Google's search bar often yields real-time flight status information.

Can I track my flight's status using the flight number?

Absolutely! You can track your flight's status using the flight number. Input your flight number on flight tracking websites like FlightAware or FlightRadar24 to access real-time information about your flight, including departure and arrival times, delays, cancellations, gate changes, and the aircraft's current position.

Airlines also often offer flight status information on their websites or through mobile apps, where you can input your flight number to receive updates.

Examples of retired flight numbers due to historical accidents

Airlines often retire flight numbers associated with tragic accidents or incidents out of respect for the victims and their families. Some examples of retired flight numbers include:

  • American Airlines flight AA11, United Airlines flights UA93 and UA175: These three flight numbers were retired following the September 11, 2001, terrorist attacks.
  • Malaysia Airlines flight MH370: The flight number was retired following the mysterious disappearance of the aircraft in 2014.
  • Malaysia Airlines flight MH17: The flight number was retired after shooting down of Flight MH17 over Ukraine in July 2014.
  • TWA flight TW800: The flight number was retired after the aircraft exploded shortly after takeoff from New York JFK in 1996, killing all 230 passengers and crew onboard.
  • Germanwings Flight 4U9525: Retired after the aircraft crashed into the French Alps in a deliberate act by the co-pilot in March 2015.
  • Asiana Airlines Flight OZ214: Retired after the Boeing 777 crashed while landing at San Francisco International Airport in July 2013.
  • Air France Flight AF447: After the tragic crash in the Atlantic Ocean en route from Rio de Janeiro to Paris in June 2009, Air France retired the flight number.


  1. International Civil Aviation Organization, Flight Identification and Designators (PDF)
  2. FlightAware, Track flights by flight number
  3. Wikipedia, Flight number

Flying soon?

The ultimate guides to cheap flights.