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):

  • 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

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.

Some plates are banned each year for being too rude - here's the latest list of banned number plates...

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