This is a list of country codes on UK issued diplomatic vehicle registration plates, i.e. the first group of three numbers.^[1]

Since 1979, motor vehicles operated by foreign embassies, high commissions, consulates and international organisations have been issued unique vehicle registration marks with a distinguishing format of three numbers, space, letter D or X, space and three numbers. The letter D is used for diplomats and X for non-diplomatic accredited personnel.^[2]

The first group of three numbers identifies the country or international organisation. The second group of three numbers is a serial number sequence starting at 101 for diplomats, 400 for non-diplomatic staff of international organisations, and 700 upwards for consular or other non-diplomatic staff.

Eligible officials are required to be accredited by the Foreign & Commonwealth Office (FCO) who liaise with Specialist Registrations at the Driver & Vehicle Licensing Agency (DVLA) for issuance. Guidance document INF267 (4/18) has been produced by the DVLA for accredited officials.

Honorary consuls are not entitled under UK law to diplomatic vehicle registrations and/or driving permits.

Many foreign embassies and high commissions have acquired 'flag’ plates from the historic British car numbering systems, for example, CAN 1 (Canada), AUS 1 (Australia), BEL 12E (Belize), BF 1 and BF 2 (Burkina Faso), CHN 1 (China), FIJ 1 (Fiji), FRA 1 (France), 1 HKG (General-Director of Hong Kong Economic and Trade Office), IC 1 (Iceland), 1 NWY (Norway), etc.