Skip advert
Advertisement
Tips & advice

What are 4D number plates and are they legal?

Everything you need to know about so-called ‘4D’ number plates, including whether you’re allowed to have them on your car

Having a valid set of number plates is one of many requirements for legally driving your car on the road. Many drivers will purchase a personalised registration number in a bid to brighten up this rather dull fact of life, and some motorists are now following a new trend of fitting what have become known as ‘4D’ number plates.

These increasingly common plates feature raised lettering that stands out more from the background of the plate. Despite their popularity, however, more and more incidents of police stopping vehicles with these types of number plates have been reported, particularly on social media. This has led drivers to question what the rules are on what at first appears to be a grey area.

What are the rules for number plates?

In the UK, number plates have to meet the following criteria set out by the Driver and Vehicle Licensing Agency (DVLA):

Advertisement - Article continues below
  • Number plates must be made from a reflective material
  • Number plates must display black characters on a white background at the front and black characters on a yellow background at the rear
  • Number plates must not have a background pattern
  • Number plates must be marked to show who supplied the number plate
  • Number plates must be marked with a British Standard number - this is ‘BS AU 145e’ for plates fitted after 1 September 2021
Skip advert
Advertisement
Skip advert
Advertisement - Article continues below

There are also strict rules governing the size and shape of the letters on a number plate. These must be printed in Charles Wright font, with characters 79mm in height, 50mm in width and with a space between them of 11mm.

The DVLA also states that, in addition to having a choice of national identifier for the strip on the left-hand side of the number plate, drivers can choose to have what it describes as “3D (raised) characters”.

Are 4D number plates allowed?

In spite of the DVLA specifically stating that number plates can have raised lettering, the rules are more complex in reality.

As Sergeant Dan Pascoe from Surrey Road Policing Unit explained to us, although there is no law against a number plate having raised lettering in itself, the characters can’t stick out so much as to obscure the registration from being legible from an angle.

Another issue with so-called ‘4D’ plates is that the characters aren’t always built into the structure of the number plate and are instead stuck on with adhesive. This means they can actually fall off over time, leaving the driver with an incomplete, and therefore illegal, plate.

As such, the advice is for drivers to stay on the safe side and stick with conventional 2D number plates.

More on car number plates...

Skip advert
Advertisement
Skip advert
Advertisement

Recommended

Eyesight requirements for driving: UK eyesight rules explained
eyesight

Eyesight requirements for driving: UK eyesight rules explained

What is the minimum vision standard required to drive on UK roads? And how can you check your own eyesight before driving? Our handy guide has you cov…
Tips & advice
29 Jan 2026
Cheapest cars to run 2026
Cheapest cars to run - header image

Cheapest cars to run 2026

When it comes to total cost of ownership, cut-price entry-level models aren’t always the best. So what are the cheapest cars to run in the UK today?
Best cars & vans
27 Jan 2026
How to clean alloy wheels: tips to keep your car’s wheels clean and protected
Auto Express Product Awards 2016 - wheel cleaner

How to clean alloy wheels: tips to keep your car’s wheels clean and protected

Alloy wheels can get dirty pretty quickly. Here's how you can keep them looking fresh with an alloy wheel cleaner.
Tips & advice
27 Jan 2026
How to wash your car
How to wash your car - header

How to wash your car

A step-by-step guide on the basics of how to hand wash your car and make it shine
Tips & advice
21 Jan 2026

Most Popular

New XPeng X9 seven-seater ‘starship’ will beam down to the UK this summer
XPeng X9 - front static

New XPeng X9 seven-seater ‘starship’ will beam down to the UK this summer

Chinese brand’s “starship of tomorrow” has rear-wheel steering, adaptive air-suspension and some of the fastest charging speeds of any EV around
News
30 Jan 2026
Dacia Bigster vs Citroen C5 Aircross: low prices and plenty of space, but which SUV does it best?
Dacia Bigster vs Citroen C5 Aircross - front tracking

Dacia Bigster vs Citroen C5 Aircross: low prices and plenty of space, but which SUV does it best?

Citroen’s latest C5 Aircross hybrid is aiming to woo budget family SUV buyers, but standing in its way is the wallet-friendly Dacia Bigster hybrid
Car group tests
31 Jan 2026
Big discount on Hyundai Kona Electric as it's green-lit for Government EV grant
Hyundai Kona Electric - front corner tracking

Big discount on Hyundai Kona Electric as it's green-lit for Government EV grant

South Korean brand’s popular electric SUV now starts from £33,500 for the entry-level Advance model
News
30 Jan 2026

Find a car with the experts