Car number plates explained

What number plates mean and buying a personalised plate: the full guide

By BuyaCar team

Every car on the road has a unique combination of letters and numbers on its number plates. While you may not pay too much attention to your number plates, they serve a huge range of purposes - including alerting the police if anything’s untoward, or making sure your autoparts store gives you the right bulb or wiper for your car.

A car gains its number plates when it’s registered - they’re also called registration plates for this reason - and the plates must be fitted before it can be driven on the road. The car’s details, such as make, model, engine size and colour are logged on a database and it's issued a unique registration number. This must be displayed on a number plate on the car, and should be considered as an identification card.

Under the current UK system, a car registered in March-August 2021 would have a number plate like this:


And a car registered between September 2021 and February 2022 would have a number plate like this:


In this format, the first two letters indicate where the car was registered, each region has a different code and 'AA' would in fact relate to a car registered in Peterborough. Some are more obvious than others; cars registered in the Birmingham area have plates with ‘B’ at the start, and then a second letter, while a number plate with ‘L’ at the start means the car was originally registered in London.

The following numbers identify the age of the car, the current format for number plates was introduced on September 1 2001, and began with the number 51. This was replaced by updated plates in March 2002, and the same system remains in place today.

From then on, new number plates have been released every 6 months in March and September, counting up from '02' and '51' respectively each year. A car registered in April 2002 would have '02' as it's age identifier, July 2003 would have '03' and so on. while a car registered in September 2009 would have '59', February 2017 would have 67.

The final three letters are randomised, and help to single out a particular car. However, if you’re buying a new car that hasn’t yet been registered, you can sometimes choose the last three letters from a selection assigned to your dealership.

A number plate with three letters then four numbers is from Northern Ireland, while plates for diplomat cars are different again, with three numbers followed by one letter and three subsequent numbers.

Can you choose your number plate?

Your car's initial number plate is automatically assigned, so you don't get to choose your preferred combination of letters and numbers. You can change this by buying a personalised registration and paying the DVLA to transfer this to their vehicle.  

Personalised number plates

You can buy a personalised registration number from independent companies as well as from the DVLA’s Personalised Registrations department.

Some follow the same format as the current standard number plate, but others have a different layout, as they were generated before the current system was introduced. Some will already have been issued, then sold on by their previous owners. Others will have never been used before being auctioned or sold by the DVLA. These can command enormous prices: 'K1 NGS', 'VIP 1' and '25 O' have all been reported as selling for more than £100,000 each.

The DVLA’s prices start at £250. It also holds regular auctions of numbers and also sells some directly for a fixed price. It claims that over the past 25 years its sales of personalised numbers have raised over £2 billion.

Once you've bought a personalised registration, it can be transferred to any subsequent vehicles, but it's important to follow the right process or you could lose the right to use it.

Why buy a personalised number plate?

For some, it's the novelty of having a plate that includes their initials or, less commonly, their full name, as seen above. Others like to match it to the name of their car (F13 STA might appeal to a Ford Fiesta owner, for example).

Personalised plates can also disguise the age of a car. It's illegal to make a car look newer than it is, so you can't fit a number plate with a 2018 ‘18’ age identifier to a 2016 vehicle. But older formats will mean that no-one will know when your car first hit the road.

For others, there's a commercial value. 'CH11PPY', 'F1 PRO' and 'CAB 13IE' are some of the plates that have been issued. Pimlico Plumbers, a London-based plumbing firm, has a fleet of vans with personalised registration numbers that reflect its business. They include '1 BOG', 'C15TERN' and 'TAP 15 ON'.

Changing number plate spacing

Any tinkering with a car's registration number is an offence, not least because it can make them less easy to read by police number plate recognition cameras. Get caught and you could be fined up to £1000.

This includes adjusting the spacing of digits (e.g. 'S4 RAH' is more clearly the name ‘Sarah’ when written as 'S4RAH'), other tricks such as placing a screw between the figures ‘11’ to make them resemble an ‘H’ or changing the font from the standard. Changing the font is also not permitted. You can buy number plates with different fonts legally, but these are technically ‘show plates’ and are illegal if you use them while driving on the public highway. 

Most expensive number plates

Desirable personalised registration numbers also have real investment value, and prices for the best can be astronomical. For example, '25 O' sold for £518,000, while 'F 1' went for £440,000. 'S 1', claimed by its seller to be Scotland’s first number plate, went for £404,000, while '1 D' sold for £352,000.

Naughty number plates

A special panel of experts meets twice a year at the DVLA to consider the appropriateness of new registration numbers. Those likely to cause general concern, offence or embarrassment, or be politically or racially insensitive, are likely to be withheld.