Less than most people expect. The font is fixed, the sizes are fixed and the spacing is fixed. Those are not style choices, they are the law.
What you genuinely choose is the finish (flat, gel or raised), whether to add a black border, and whether to add a national flag. That is the list.
Everything else sold as a "style" is either one of those three things under a different name, or it is illegal.
The one font you are allowed
Charles Wright. That is it. There is no legal alternative, no decorative option and no "close enough". It has been the mandatory typeface on UK plates since 2001, and a plate in any other font is illegal whatever else is right about it.
The measurements are fixed with it:
| Measurement | Required |
|---|---|
| Character height | 79mm |
| Character width | 50mm (except the number 1 and letter I) |
| Stroke width | 14mm |
| Space between characters | 11mm |
| Space between the two groups | 33mm |
| Top, bottom and side margins | 11mm minimum |
So when a seller advertises "fonts" or "custom lettering", they are either describing the finish, or selling you something you cannot legally put on a road car.
The three legal finishes
This is where the real choice is. All three are road legal, because what matters is that each character is a single solid shade of black, not whether it is flat or raised.
2D flat
Printed directly onto the reflective face. The finish every car leaves the factory with, and the least likely to be questioned by anyone.
3D gel
The character is printed, then a clear resin dome is moulded over it. Glossy and rounded, with the light catching the curve.
4D
Characters laser cut from solid acrylic, usually 3mm, and bonded to the plate face. Sharp edges and a hard shadow. How 3D gel and 4D differ goes into this properly.
The two extras you can add
A black border
Legal, and purely cosmetic. It must not interfere with the characters or the margins.
A national flag and identifier
One flag, on the left of the plate, from a short permitted list: the Union flag, the Cross of St George, the Saltire, or the Red Dragon of Wales. Each can carry its identifier, such as UK, ENG, SCO, CYM or WALES.
The EU flag and the GB identifier are no longer valid on UK plates. If you are driving abroad you now need a UK sticker unless your plate carries the Union flag with UK.
The rear plate is yellow, always
Not a style choice either. White reflective at the front, yellow reflective at the rear, on every car. The only thing you choose is whether the finish matches across both.
The styles that are not legal
These get sold, and they get people fined. A non-compliant plate can mean a fine of up to £1,000, an automatic MOT failure, and the registration being withdrawn.
Altered spacing
Moving characters so the registration reads as a word or a name. This is the single most common reason a plate is pulled up, and it is illegal regardless of the finish.
Shaded or two-tone characters
The printed "3D effect" font, where grey shading is used to fake depth on a flat character. Banned for plates fitted from 1 September 2021, because a character using black and grey is not a single shade of black. This is the rule that got misreported as a 3D and 4D ban.
Tinted, ghost or stealth plates
Anything applied over the plate to make it harder to read, from any angle or in any light. Illegal, and treated more seriously than a cosmetic breach because the intent is to defeat identification.
Anything else on the plate
No background patterns, no logos, no badges, no non-permitted flags, no contrasting character outlines. The plate carries the registration, the British Standard mark, the supplier details and nothing more.
Source: GOV.UK, Displaying number plates. Worth reading yourself rather than trusting any plate seller, ours included.
Where show plates fit
Everything above applies to a plate on a public road. Show plates are a different thing: any text, any layout, no entitlement documents, because they are for car meets, displays and off-road use only. They are not road legal and fitting one on the road is the same offence as any other illegal plate.
If what you actually want is your name or a word on a plate, that is what a show plate is for.
SEE YOUR REGISTRATION IN EACH FINISH
Type your reg into the builder and switch between 2D and 4D to see the difference on your own plate before you order.
Open the plate builder