Are 4D Number Plates Legal in the UK?

Are 4D Number Plates Legal in the UK? (2026 Guide)

Short answer: yes. 4D number plates are fully legal in the UK when manufactured to BS AU 145e:2018 standards. There's no ban on them — but a lot of the cheap plates sold online don't actually meet the legal requirements, and that's what gets people caught out.

What makes a 4D plate road legal

4D plates use laser-cut solid acrylic characters bonded onto the plate background, giving that raised, premium look. To be legal, they need to tick every one of these boxes:

• Solid black characters only — no carbon fibre effects, ghost tints, or coloured acrylic 
• Correct font — the mandatory Charles Wright 2001 typeface, no exceptions
• Correct size and spacing — characters must follow the legal dimensions and character spacing rules
• Reflective background, non-reflective characters — only the background substrate is allowed to be reflective, not the characters themselves 
• Supplier ID visible — a compliant plate shows the manufacturer's registered number plate supplier (RNPS) details

At KW Kustoms, every 4D plate we supply is made to full BS AU 145e spec, so you get the look without the risk of an MOT failure or a fine.

What could get you in trouble

Tinted or smoked-effect plates are a common issue — if the plate obscures or reduces legibility of the characters (including for ANPR cameras), it's not road legal, regardless of how sharp it looks. Two-tone or coloured character effects fall into the same category.

The bottom line

4D plates are a great way to smarten up your car and they're completely road legal — as long as they're made properly. Get yours from a registered supplier, and you can enjoy the upgrade without worrying about the police, MOT testers, or the DVLA.