Key points
- Raised 3D gel and 4D acrylic characters are legal when every character is one solid shade of black.
- BS AU 145e banned grey shading, two tone and highlight effects from 1 September 2021, not raised characters.
- Tinted, smoked, ghost, neon, glitter and outlined finishes are not road legal.
- Every number plate defect is a major MOT fault, so one illegal plate fails the test.
- An illegal plate can bring a fine of up to £1,000.
- Plates fitted before 1 September 2021 to BS AU 145d stay legal.
- A proposed BS AU 145e amendment would require flat plates, but it is not law yet.
- Buy from a DVLA registered supplier that prints its name, postcode and BS AU 145e on the plate.
Are 3D and 4D Number Plates Legal
Short answer: yes. 3D and 4D number plates are legal in the UK when every raised character is a single shade of black, the plate meets the BS AU 145e standard and the font, size and spacing follow the display regulations. What changed in September 2021 was not a ban on raised plates but a ban on shading and two tone effects. This guide sits under our uk number plate rules and the law and covers exactly where the line falls.
The Short Answer: When Raised Plates Are Legal
Legal | Not legal |
|---|---|
Raised 3D gel characters in solid black | Grey or coloured shading that fakes depth on plates supplied from 1 September 2021 |
Laser cut 4D acrylic characters in solid black | Two tone, outlined or neon edged characters |
4D gel: black acrylic under a clear gel cap | Tinted, smoked or ghost finishes |
Gloss or matte black, as long as it is one shade | Glitter, sparkle or reflective characters |
Plates marked BS AU 145e with the supplier name and postcode | Carbon fibre or patterned backgrounds |
What Changed for 3D Plates in September 2021
Plates supplied from 1 September 2021 must meet BS AU 145e. GOV.UK confirms that plates can have raised characters but that the characters must be a single shade of black. Before 2021, many plates used printed grey shading to make flat characters look three dimensional. That shading is what the standard removed, because cameras need a clear, single contrast between character and background. Raised characters that are genuinely raised, such as gel domes and acrylic letters, were never banned.
Plates fitted before 1 September 2021 to the older BS AU 145d standard remain legal, so you do not need to replace older shaded plates until they are next changed.
Why Shaded and Tinted Plates Were Banned
Number plates are read by people and by automatic number plate recognition (ANPR) cameras, which use infrared light. Shading, outlines and tinted covers reduce the contrast between the character and the background, so a camera can misread or miss a registration. BS AU 145e added a near infrared contrast test for exactly this reason, as the British Number Plate Manufacturers Association explains. A raised character in solid black passes that test; a shaded or tinted one may not.
How the MOT Treats 3D and 4D Plates
The MOT inspection manual sets the test. Every number plate defect is a major fault, so one illegal plate means a failed MOT. The tester checks that characters are the correct size, stroke width, spacing, layout and font, that there is no background pattern, and that no tint or film changes how the characters look. Grey shading to give a 3D effect is only accepted on vehicles first used before 1 September 2021. On anything newer, every character surface must be one shade of black.
3D vs 4D Plates: How They Differ
3D gel | 4D | |
|---|---|---|
Build | Clear polyurethane gel domed over black characters | Black acrylic characters cut by laser and bonded on |
Edge | Rounded and glossy | Square and crisp |
Depth | A low dome | 3mm or 5mm, or with a gel cap |
Legal when | The gel is clear and the character is solid black | The acrylic is solid black and not reflective |
Both are legal 4D number plates or 3D plates when made to the standard. For the finishes we make, see 3D gel number plates and 4D number plates.
How to Tell If Your 3D or 4D Plate Is Legal
Look along the bottom edge: the supplier name, postcode and BS AU 145e should be printed there
Check the characters from an angle: they should be one solid black, with no grey shadow, outline or coloured edge
Check the gel or acrylic is not tinted: the background around the characters should be bright white or yellow
Compare the gaps: characters should be evenly spaced, with one wider gap between the two groups
Check the font: square, upright characters with no italic, stencil or novelty shapes
If the plate fails any line, it can fail the MOT and bring a fine of up to £1,000. Our guide to ghost and tinted number plates covers the finishes that cause most problems.
Show Plates Are a Different Product
Many sites sell neon, glitter and two tone 4D plates. They are show plates, legal to buy for car shows and private land but not to drive with. If a 3D or 4D finish is sold with a coloured edge or a tinted cover, treat it as a show plate, whatever the listing says.
Buying Legal 3D and 4D Plates
Raised plates are only as legal as the supplier that makes them. Buy from a DVLA registered number plate supplier that asks for your identity and entitlement documents, prints its name, postcode and BS AU 145e on the plate, and keeps show finishes separate from road plates. A listing that calls a neon or tinted 4D plate "road legal" is a warning sign about the whole seller.
Frequently asked questions
Are 4D number plates legal in the UK?
Yes, when the laser cut acrylic characters are a single shade of black, the plate meets BS AU 145e and the font, size and spacing follow the regulations. Neon, two tone and tinted 4D plates are not legal on the road.
Are 3D number plates legal?
Yes. Raised 3D gel characters are legal when the gel is clear and the characters underneath are solid black. Printed grey shading that fakes a 3D effect is not allowed on plates supplied from 1 September 2021.
Were 3D number plates banned in 2021?
No. BS AU 145e banned two tone and shaded effects, not raised characters. Genuinely raised gel and acrylic characters in one shade of black remain legal.
Will 4D plates fail the MOT?
Not if they are compliant. Every number plate defect is a major MOT fault, so a 4D plate with tinted, outlined or incorrectly spaced characters will fail, while a compliant one passes.
Are matte black 4D plates legal?
Yes, as long as every character is one shade of black and not reflective. Matte and gloss are both single shade finishes.
Do I need to replace my older 3D effect plates?
No. Plates fitted before 1 September 2021 to BS AU 145d stay legal, and the MOT accepts grey shaded 3D characters on vehicles first used before that date.
What is the fine for illegal 3D or 4D plates?
Up to £1,000, and the vehicle will fail its MOT.