Do front and rear number plates have to match?

Plate Legality · 2 September 2026 · 4 min read

They must show the same registration and both must be legal. Beyond that you've got more freedom than people think: different sizes, and even different finishes, are allowed.

What has to match

Two things, and they're the obvious ones. Both plates must show the same registration, and both must comply with BS AU 145e: correct font, size, spacing, reflective background, solid black characters, maker's details and BS mark.

That's the whole list. Nothing in the regulations says the two plates have to be the same size, the same shape or the same finish.

What has to be different

Colour. The front plate is white and the rear plate is yellow, always. A white rear plate or a yellow front is a fail, and one of the few plate offences that gets spotted from across a car park.

What's allowed to differ

Size. Plenty of cars run a standard 520 mm front with a different rear: a 21" x 6" rear on a 4x4 or van with a square recess, or a shorter plate on a car with a narrow bumper. Each plate just has to keep legal characters and margins on its own. The sizes guide lists the options.

Shape. A hex front with a standard rear, or the other way round, is fine as long as each is individually legal.

Finish. You can have a 4D front and a printed rear. We get asked this most by people who've cracked one plate and want to replace just that one. The rules don't care that one set of letters is raised and the other isn't. That said, most people who order one raised plate end up coming back for the other.

Border and badge. Same principle: each plate on its own merits. Though if you've got a flag on one and not the other it looks like an afterthought.

Motorcycles

Motorcycles and trikes only need a rear plate. There's no front plate to match, and a front plate isn't permitted on a bike registered after 2001. Sizes and rules are in the motorcycle plates guide.

Replacing one plate

If one plate is damaged you can replace it on its own. You'll need the same documents as for a pair, because it's still a road-legal plate being made to your registration. The documents guide has the list. In the builder, untick the plate you don't need and the price adjusts to a single.

The one mismatch that catches people out

A private registration transferred onto the car, with the new plate on the back and the old one left on the front because it was screwed on and awkward. Two different registrations on one car is an offence on the spot. If you're changing the number, change both plates the same day.