Any UK registration marks that are currently in use or have been registered in the past are not re-issued to a second aircraft to avoid any confusion. An individual airframe may have more than one registration mark in its lifetime, but a particular registration mark can only apply to one airframe.
It is possible to reserve out-of-sequence marks in your name for future use for a period of six months. At the end of the six months period the reservation can be renewed if necessary. At the time of reservation we do not require details of the aircraft type or serial number just the details of the name to whom it is to be reserved and the relevant fee. For an application form and to ascertain the current fee please see forms and fees. Please note that the reservation fee is not deductible from the registration fee once the aircraft itself is registered using the previously reserved marks.
G-INFO, the UK Register database can be used to check on the availability of registration marks. If a mark does not appear on the database it is generally available, however some combinations of letters are not used at all and some marks may be reserved for future use. These non-available marks do not appear on the database but are not available for allocation. After checking the database it is advisable to contact the Aircraft Registration section direct with your requests for availability.
Examples of combinations of letters that are not issued are PAN, SOS, TTT, XXX and ZC. Also note the UK Register no longer uses the letter Q in registration marks. Other combinations which may be considered offensive may also be excluded at Aircraft Registration’s discretion.
There are two different types of registration marks currently issued, in-sequence and out-of-sequence marks. These differ in the fee for registration of each one, see forms and fees. In-sequence registrations have been used since 1919 starting at G-EAAA to G-EBZZ and then starting again at G-AAAA. The current sequence reached G-CBAA during 2001. Each aircraft in turn is allocated the next sequential mark within a range of three blocks of registrations (e.g. if the next mark to be issued is G-CBAA then an in-sequence mark is any between G-CBAA and G-CBCZ which has not already been used, this means there are always 75 in-sequence marks to chose from). In-sequence marks cannot be reserved but a choice can be made from the 75 currently available in-sequence marks at the time of registration by entering "please telephone" at question 4 on the CA1 application for Registration of Aircraft form. Out-of-sequence registrations are all others which have not currently been issued.
The British Gliding Association (BGA) is the recommending organisation for gliding in the UK and they maintain a record of gliders in the UK. One of the existing methods of glider identification is a three letter code (trigraph) issued by the BGA, by default, the trigraph can be used as the last three letters of the UK Registration mark. For example, if the BGA trigraph is PXL the aircraft would be allocated the next available UK registration mark that contains PXL as the last three letters, so if G-CPXL is not available the aircraft will be allocated G-DPXL and so on. As the letter Q cannot be issued on a UK registration mark if a glider trigraph contains the letter Q then a standard in-sequence mark is issued in place of a trigraph related mark. Out of sequence registration marks can also be used on gliders in place of a trigraph related or in sequence mark.
There are no longer any historical registration marks available for issue (i.e. between G-AAAA and the current in-sequence range) unless it is the original aircraft that is being re-registered or restored to the UK Register. Generally an original aircraft can return to any of the UK registration marks that it has previously carried.
Each aircraft is allocated only one in-sequence mark although it is possible for the same aircraft to have an unlimited amount of out-of-sequence marks in its history. Registration marks cannot be re-used on different aircraft even if the original aircraft that carried the marks has been registered overseas or destroyed.
There are no longer separate blocks of marks issued to microlight or small light aircraft, these aircraft are now entered in the main in-sequence blocks or given out-of-sequence marks if requested. Minimum lift balloons are confined to the G-FYAA -ZZ blocks.