Number Plate Rules for Trailers and Caravans in the UK

Do trailers and caravans need a number plate?

Yes. In the UK, any trailer or caravan used on public roads must display a rear number plate showing the registration of the towing vehicle. This is a legal requirement under the Road Vehicles (Display of Registration Marks) Regulations 2001.

What registration does a trailer display?

A trailer does not have its own registration number. It displays the same registration as the towing vehicle on a separate rear plate. So if your car is registered AB12 CDE, your trailer must display AB12 CDE on its rear plate.

Does the trailer plate need to match the tow vehicle’s plate style?

No legal requirement says the styles must match, but both plates — the tow vehicle’s and the trailer’s — must individually comply with BS AU 145e. The trailer plate must use the correct Charles Wright 2001 font, correct spacing, correct reflective backing, and include the manufacturer’s name and postcode.

Can a trailer have a 3D or 4D plate?

Yes. Provided the plate is BS AU 145e compliant and displays the towing vehicle’s registration correctly, there is no restriction on style. 3D gel and 4D laser-cut trailer plates are legal and look far smarter than a basic flat plate. Many caravan and trailer owners upgrade to match the style of their tow vehicle’s plates.

What size plate does a trailer need?

Standard UK plate dimensions apply — the same as a normal rear plate. There is no special size category for trailer plates. The standard oblong format (520mm x 111mm) is the most common for trailers and caravans, though some trailers use a square format plate. Check your trailer’s plate recess dimensions before ordering.

Do you need to show the supplier name on a trailer plate?

Yes. Like any road-legal plate, a trailer plate must include the name and postcode of the DVLA-registered supplier who manufactured it. This is a requirement of BS AU 145e.

What about caravans?

The same rules apply to caravans as to trailers. The caravan displays the towing vehicle’s registration on a rear plate. The plate must be BS AU 145e compliant, lit correctly at night (if your caravan has a number plate light), and legible.

When might a trailer have its own registration?

Most trailers under 3,500kg gross weight do not need their own registration. However, certain agricultural and commercial trailers over specific weight thresholds may require their own registration under the Road Vehicles (Registration and Licensing) Regulations 2002. If you operate a large commercial trailer, check with the DVLA directly.

What if the trailer plate gets damaged?

A cracked, faded, or illegible plate must be replaced. Driving with an illegible plate — whether on the tow vehicle or the trailer — is an offence. Car Plates Pro can make a replacement trailer plate for the same price as any other replacement plate. Standard plates start from £6.99, and we offer same-day dispatch on orders placed before 2PM.

Ordering a trailer plate from Car Plates Pro

When ordering, simply enter your vehicle’s registration (the towing vehicle’s registration, not a trailer-specific number). Select your preferred plate style — standard, 3D gel, or 4D. All plates are BS AU 145e compliant, made from 5mm acrylic, and include free sticky pads. Royal Mail Tracked 24 delivery reaches 98% of UK addresses the next working day.

Summary

• Trailers and caravans must display the towing vehicle’s registration on a rear plate
• The plate must be BS AU 145e compliant
• Any style (standard, 3D, 4D) is legal provided it meets BS AU 145e
• Standard oblong dimensions apply — check your trailer’s recess before ordering
• Damaged or illegible trailer plates must be replaced