Trailer number plates: an ordering and fitting guide
Check which registration a UK trailer should display, order the correct rear plate and understand the separate rules for some trips abroad.
Use the towing vehicle's registration in the UK
For ordinary UK towing, GOV.UK says the trailer must display the same registration number as the vehicle towing it. If you change the towing vehicle, check the trailer plate before setting off rather than assuming the registration is still correct.
The trailer plate is fitted at the back, where it can be seen clearly. If more than one trailer is being towed, the number plate must be fixed to the trailer at the back of the combination.
Order a yellow rear plate
A domestic trailer plate matching the towing vehicle is a rear plate, so it uses black characters on a yellow reflective background. Copy the registration directly from the vehicle or its documents and check every letter, number and group space in the preview.
In the Vista builder, choose Rear and Road Legal for a plate intended for public-road use. Then review the size, lettering, badge, border and fixings available for that specification. A trailer mounting area does not change the required registration layout.
Measure and check the mounting position
Measure the flat usable area on the trailer, including any existing holder, lights, hinges and fixing points. Check that the complete plate can sit securely without covering a lamp or being hidden by a load, strap or accessory.
Use fixings suitable for the plate and trailer. Keep screws and caps clear of the registration characters, fit the plate upright and check that vibration cannot loosen it. Inspect the plate and holder again after the first journey and before longer trips.
Prepare the documents for a road-use plate
GOV.UK says number plates can only be made up by a registered supplier. The supplier needs original documents proving your name and address and your entitlement to use the registration. For a plate matching the towing vehicle, the official list includes documents such as the V5C or green new-keeper slip.
A compliant replacement must also meet the current road-use requirements for its reflective background, characters, supplier details and applicable British Standard marking. Select the complete specification for its intended use rather than treating a yellow background alone as confirmation.
Check the separate rules before towing abroad
Some trailers must be registered before they are taken through or to countries abroad. GOV.UK currently says trailers over 750kg must be registered for travel through or to most European countries, apart from Ireland, Cyprus, Malta and Spain; use the official service to check the exact journey and trailer.
When a trailer needs its own registration, its trailer registration plate is displayed as well as the towing vehicle's number plate. GOV.UK says the two plates should be fixed as far apart as possible at the back. If the trailer registration plate cannot be fitted at the back, it must be fitted on both sides and remain clearly visible.
Official guidance checked on 13 October 2026. Recheck the destination and trailer-registration rules before travelling.
- Match the domestic trailer plate to the current towing vehicle.
- Choose Rear and Road Legal for a UK road-use order.
- Measure around lights, hinges and the existing holder.
- Keep fixings clear of every registration character.
- Check trailer-registration and destination rules separately before travelling abroad.