4D number plates: everything you need to know | CAR Magazine

4D number plates: everything you need to know

Published: 28 February 2022 Updated: 28 February 2022

► 4D plates explained
► How to keep it legal
► Everything you need to know

Following a series of tweets from Surrey’s Road Policing Unit (RPU), motorists nationwide are questioning the legality of their personalised number plates. The growth in 3D and 4D number plates has prompted the RPU to try and clarify the position on number plates with raised letters and numbers, after seizing many which didn’t meet the criteria for legality.

According to the RPU’s tweet ‘The DVLA has stated ‘The agency has not seen any evidence to show that number plates displaying raised plastic, acrylic or perspex lettering (3D/4D plates) are able to meet the requirements of either the current or new the British Standard.’

Businesses selling these 3D and 4D number plates, however, have challenged these comments. And rightly so. Not least because, in September 2021, following changes to the regulations, the Government said: ‘The new British Standard for retroreflective number plates does not state that number plates with raised characters, including 3D gel and 4D number plates, will not be permitted.’

For a time, some drivers had used different shading to give the impression of a 3D plate on a 2D one. This isn’t allowed, so the changes made it clear that numbering and lettering on number plates has to be all one solid black colour.

What does 4D even mean?

It’s a fair question, since the fourth dimension, mathematically speaking, is time. But the distinction between 3D and 4D is all to do with the sharpness and definition of the raised lettering. If it’s quite soft, it’s 3D. If it’s more pronounced, it’s 4D. These differences are most easily understood in the image below.

Are my 3D or 4D plates legal?

Number plates have evolved over the years with the criteria changing as the volume of car sales has increased. The rise in the use of ANPR and fixed speed cameras has prompted police to clamp down on drivers intentionally trying to evade prosecution by using plates that can’t be read by the cameras.

Can your plates be read by cameras clearly? If so—and they comply with the standards below—most probably, they’re legal. 

There are basic standards to keep your 2D number plate legal, but there are additional tests done on 3D and 4D plates to ensure they meet, at the very least, build quality. There have been instances of lettering dropping off, after being stuck on like hobbycraft, rather than professionally bonded.  

The basic standards to keep your number plate legal

The DVSA states that number plates need to be an untitled font, colloquially known as Charles Wright New or Mandatory. Opt for a different font and you’re putting yourself in a position of vulnerability. The letters and numbers must comply with specific spacing and alignment, as the table below shows.

There are three groups;

Group 1 plates

These apply to plates dating between January 1973 and September 2001. The initial letter was a single alphabet character, followed by two numbers, unless private. The following three letters were a random configuration, to give the plate the unique identifier. 

Group 2 plates

Rules applying to plates before January 1973, many of these plates don’t follow the modern conventions for colour, with classic cars and motorcycles using a black background with white or silver lettering. 

Present day, post-September 2001

Applying to all vehicles registered since September 2001, these are today’s standards for modern plates. The rear plate is yellow and the front plate is white. 


Present (post-Sept 01)

Group 1 (pre-Sept 01)

Group 2 (pre- Jan 73)

Character height




Character width (exc. Number ‘1’ or Letter ‘l’)




Character stroke




Space between characters




Space between age identifier & numbers i.e. Gap




Top, bottom & side margins minimum




Vertical space in gap (if across 2 lines)




When it comes to national flags, country identifiers and the green tag to denote an electric car, these must always be on the left, no more than 50mm wide and are strictly limited to the accepted flags and abbreviations, e.g. England, ENG. It’s also worth noting GB bumper stickers have changed to ‘UK’ bumper stickers and are required if travelling abroad.

Tips to stay legal and the penalties involved

Buying your 3D or 4D number plate from a reputable supplier, which has certified approval from the DVLA to retail plates, is one way of ensuring your plates stay on the right side of the law. There’s a requirement to have both the plate manufacturer and the plate supplier’s details on the number plate—usually, but not always, found along the bottom. 

Keeping the car, especially the number plate clean can help you avoid a massive payout and being scammed, too. Dirty number plates can cost motorists up to £1,000 in fines, but there’s an added risk. If your plate gets cloned by criminals and your genuine plate is too dirty to identify you in your locality, you may find yourself being accused of crimes you didn’t commit.

On-the-spot fines of £100, fixed penalties of up to £1000 and possible seizure of your assets by the police are some of the consequences you can face with an illegal plate. Seizure is less common, but possible if it’s the evidence police need to prosecute you. More likely, if you’re a first-time offender, they’ll issue you with a ‘vehicle defect rectification notice’, giving you 14 days to get the plate made legal and the form stamped by an official supplier, which then gets handed in to your local station.

Yet, if the police don’t force you, your local MOT garage might. Having a legal plate is one of the criteria required for a pass when the car’s inspected on its annual check. One way or another, you will eventually have a legal number plate. 

By Cat Dow