Information about the allocation of ICAO 24-bit aircraft addresses.
An ICAO 24-bit aircraft address is automatically allocated to every UK Registered aircraft as part of the process to register the aircraft regardless of whether the individual aircraft is fitted with a Mode S transponder. Applicants will be advised of their allocated aircraft address in accordance with our service standards following receipt of their application to register their aircraft. Details of how to register an aircraft.
Details of allocated addresses for all UK registered aircraft are available via the G-INFO UK Register database.
If an aircraft changes to a different UK Registration mark then the ICAO 24-bit aircraft address remains the same. However, once an aircraft is removed from the UK Register the previously assigned ICAO 24-bit aircraft address must not be used. A new address will be issued by the new state of registry
For further details on ICAO 24-bit aircraft addresses and Mode S please see the Mode S home page.
If an operator needs an ICAO 24-bit aircraft address for a civil aircraft in the UK that is not required to be UK registered (such as Annex II gliders operated through the British Gliding Association scheme) please contact the Aircraft Registration Section for further details and include details of the aircraft concerned.