Choosing a callsign

Aviation call signs are communication call signs assigned as unique identifiers to aircraft. Call signs in aviation are derived from several different methods depending upon the type of flight operation being down by the aircraft. While the possibilities to choose a callsign can seem endless, callsigns must follow various constraints that allow ATC to do their job effectively and help ATC provide any needed services. The objective of this page is to help you pick a proper callsign to sign onto the VATSIM network with. It is important to remember the call sign that you are flying with on the network, attentively listen for, and respond to any communications that use your call sign. Most pilots write their call sign down on a visible piece of paper when flying to help them remember it.


Trying to connect to VATSIM with an already taken callsign (by another member) will cause an error in your pilot client prompting you to change your callsign

Operator Callsigns

Commercial operators, including scheduled airlines, air cargo, and air taxi operators, will usually use an ICAO registered call sign for their company. A basic call sign ICAO designated call sign consists of two main parts.

1. ICAO Registered Three-Letter Prefix

The purpose of three-letter commercial operation identifiers is used to help shorten the details seen by air traffic control on their controlling devices. Each prefix three-letter identifier used in a call sign is assigned to ONE operator in the world. Prefix identification codes are always three letters long, no shorter, no longer. It is common to see new or inexperienced members sign on with airline callsigns such as AA, AF, SW, NW, US, etc. These DO NOT represent any airlines. It is also common to see many new pilots log on with callsigns such as AMERICAN76, TURKISH58, DELTA519, SPEEDBIRD24, etc. These are also not correct the-letter prefix operator codes.

If you are unsure of the correct ICAO prefix for your airline try checking here

2. Flight Identification (Flight Number)

Flight numbers are commonly assigned by the operator directly. They can be completely random or can be systematically used. Airlines will commonly have the flight numbers represent various factors such as the city pairing of the flight, day of the week or time of the flight, area of operation, charter or repositioning flights, and even the airline the flight is being operated for if the flight is contracted through another carrier (commonly seen in regional flying in the United States).

Flight identification numbers should be a minimum of one number in length and a maximum of four numbers in length.

How to find or choose a flight number:

Finding real-world flight numbers in today's times is very easy thanks to resources such as Flight Aware and Flightradar24 with their ability to view currently live and previously flown flights.

How to pronounce flight identifications:

When saying a flight number, each number can be pronounced individually (common outside of the United States) or together in two number combinations if four digits.

  • UAE8867 - "Emirates Eight - Eight - Six - Seven" or "Emirates Eighty-Eight - Sixty Seven"

  • BAW456 - "Speedbird Four-Five-Six" or "Speedbird Four-Fifty Six"

  • SWA45 - "SouthWest Forty-five"

  • ARG5 - "Aerolineas Five"

General Aviation Callsigns

In most countries, general aviation flights identify themselves using the call sign corresponding to the aircraft's registration number (also called a tail number). General aviation call signs are spoken by each individual letter and number using the ICAO phonetic alphabet. Aircraft registration numbers internationally follow the pattern of a country prefix, followed by a unique identifier made up of letters and numbers. Each aircraft in the world has an assigned tail number registration (including airliners) that allow government aviation authorities to keep track of aircraft. The aircraft's registration is typically painted on the side of the aircraft's fuselage. It is important to know your aircraft's type and call sign when flying general aviation on the network. General aviation pilots often have a placard with the aircraft call sign written on it located inside the cockpit or write it down on an easily viewable piece of paper. When the aircraft's registration entered in a flight plan, the dash is omitted (Aircraft marked as YR-BMA for example would be submitted as YRBMA).


You must omit all hyphens from your callsign when connecting

Country Prefixes

The prefix in which a tail number begins identifies the home origin of the aircraft. Each country in the world is assigned a unique prefix that aircraft from that country use. Country prefixes marked on aircraft are often hyphenated from the remainder of the registration number to help better identify the country of origin.

A full list of the world's tail number country prefixes can be found here on the CIA Tail Number Prefix Database.

Aircraft Registration Number (Tail Number)

The aircraft's registration number serves the same capacity as license plates on vehicles do. They are a unique identifier for the aircraft to help differentiate from others. Registration numbers vary in length and structure based on the aircraft's home country. The registration number in the VATSIM world does not have to match the plane you are flying in the simulator. Some members choose to use popular aircraft seen on social media platforms, aircraft tail numbers they have seen or flown in real life, or imaginary personally created aircraft registrations.

Military and Other Callsigns

Due to the nature of military operations, military call signs on the VATSIM network are reserved for members of a Virtual Special Operations Organizations use only. This includes military, paramilitary, or civilian government agency operations and/or activities. Violations of this policy which are outlined in the VATSIM Code of Conduct are subject to punishment. Military callsigns, unlike normal call signs, can spell different things out or may just consist of a letter and string of numbers.

Please contact the VATSIM VSOA Department or a supervisor on the network for more details regarding the use of Military Call Signs. Also, consider joining a VATSIM Special Organization to utilize a military callsign and conduct military-type operations.