Vehicle registration plates, commonly referred to as number plates, are the mandatory numeric or alphanumeric plates used to display the registration mark of a vehicle. The Crown dependencies of Guernsey and Jersey are outside the United Kingdom and the European Union, and have registration marks that are different from those used in the UK.

Jersey registration plates consist of the letter 'J' followed by one to six digits; plates may now incorporate the coat of arms of Jersey in a white strip on the left, along with the country identifier 'GBJ' (Great Britain – Jersey). This design is similar to the EU standard plate, but does not incorporate the European flag, as Jersey is outside the European Union.

Hire cars registered in Jersey display a silver letter 'H' on a red background on the left of the registration plate.

The prefix 'E' is used to designate temporary imports.

Where a vehicle is brought temporarily into Jersey... from a country in which the vehicle is not under the law of that country required to be registered, the Inspector may... assign to it an identification mark which shall be displayed on the vehicle as provided in that paragraph.
The Mark shall consist of the letter 'E' followed by a number.

— Jersey Legal Information^[1]

Cherished plates, having the format 'JSY' followed by one to three digits, are officially auctioned. Such is the desirability of low digit registration marks that these are often included in the auctions. (The new registered keeper purchases the right to display the registration mark rather than outright ownership of it.)

A Jersey "trader" plate has white letters on a red background and is made of a flexible magnetic material. These plates are for use by a bona fide motor trader on any unregistered vehicle being used in connection with the business of that motor trader.

Guernsey plates have been compulsory since 1908.

Guernsey plates consist of up to five digits, with no letters. Plates may be either silver on a black background, or black on the white/yellow backgrounds as in the UK. An oval containing the letters 'GBG' (Great Britain – Guernsey), the island's international vehicle registration, is sometimes included.^[2]

The Registration number 1 is reserved for, and displayed on the Bailiff of Guernsey's car. The official car of the Lieutenant Governor of Guernsey has no number plate. His private cars have G1 and G2 as registration numbers. Guernsey hire cars sport a black 'H' on a yellow background on a separate square plate.

From 2012 some number plates beginning with 0 and 00 was released to generate revenue for the island. Registration OO 7 is a highly desirable plate especially for fans of a successful movie starring a fictional character called James Bond or "007" originally created by novelist Ian Fleming in 1953, the plate achieved £240,000 at an auction in September 2015.^[3]

In Alderney, a jurisdiction within the Bailiwick of Guernsey, registrations are issued with the prefix 'AY' followed by a space and then 1, 2, 3 or 4 digits. An oval GBA (Great Britain – Alderney) may exist on either the left or right hand side of the plate.

Alderney is a signatory to the Internataional Road Traffic Convention in its own right.

Before the Second World War registration were issued by the States of Alderney; following the '1958 Agreement' which delegated driver and vehicle licencing to the States of Guernsey, they are issued at the Island Hall by the States of Alderney in the name of Guernsey's Vehicle Registration & Licensing Department.

There are no requirements as to how an Alderney plate is made up. An Alderney plate is commonly either white or silver on a black background (pre-1973 UK style), or black on the white/yellow (both pre-2001 and post-2001 UK typeface styles). One or two vehicles carry French style white/yellow plates or even American style, and sometimes number plates are even hand-drawn.

AY 999 is used for the principal police 4WD vehicle.

Sark and Herm ban motor vehicles other than tractors from their roads. No number plates exist. On both islands, some tractor owners still adorn their vehicles with plates though, such as 'ROSS 1' on Sark.^{[original research?]} Although not official registration numbers, these are seen as vanity plates. Tractors on Sark still have to be licensed yearly, depicted by a sticker in the window or somewhere on the vehicle, although there is no law to display plates.

• Vehicle registration plate
• Vehicle registration plates of the United Kingdom

Wikimedia Commons has media related to License plates of the United Kingdom.

• Jersey Driver and Vehicle Standards