Guidance

Trailer registration numbers and number plates (INF291)

Updated 29 August 2025

1. Trailer registration numbers

1.1 Trailer registration – background information

Under UK legislation, certain trailers that are being used internationally must be registered with the Driver and Vehicle Licensing Agency (DVLA).

This applies to:

• all commercial use trailers that weigh over 750kg in gross weight
• all non-commercial use trailers that weigh over 3,500kg in gross weight

Although not mandated in the UK, most countries expect trailers over 750kg gross weight driving to or through their country, apart from Ireland, Cyprus, Malta and Spain, to be registered and they may take enforcement action if the trailer is not registered. This applies to commercial and non-commercial trailers (for example, a caravan or horsebox).

You must register any trailer over 750kg gross weight to drive to or through most countries in Europe, to avoid the risk of enforcement action when using your trailer outside the UK.

Once a trailer has been registered with DVLA, it will be allocated a unique registration number that must be displayed on the trailer.

The trailer registration service can be found on GOV.UK.

1.2 Why we have trailer registration numbers

By law, certain trailers must display a unique registration number. These registration numbers are a way of identifying UK-registered trailers that are being driven internationally. This will help to ensure ease of travel while abroad.

1.3 Trailer registration number format

The format of the trailer registration number is one letter followed by 7 numbers, which are set out over 2 lines. Here’s an example:

1.4 Displaying trailer registration numbers

Trailer registration numbers must be correctly displayed on number plates as set out in the Trailer Registration Regulations 2018. These regulations govern how trailer registration number plates are designed and displayed.

It is an offence for the registration number to be obscured in any way that makes it difficult to read. For example, you should not use fixing bolts to change the letter or any of the numbers. Anyone who has a number plate that does not display the registration number correctly could be fined up to £1,000.

2. Trailer number plates

2.1 How to get a trailer number plate

To have a number plate made for your trailer, you must go to a registered number plate supplier (RNPS) who supplies trailer number plates.

Find your nearest number plate supplier.

You will also need to produce your trailer number plate authorisation certificate to the RNPS. We will email this authorisation to you after you have completed your online registration application, this will be valid for 5 days. When you receive your UK trailer registration certificate in the post, you can use this to get your number plates.

The supplier will also need to see original documents that prove your name and address. You can use one of the following identity documents:

• driving licence
• utility, Council Tax or rates bill from the last 6 months
• bank or building society statement from the last 6 months
• national identity card

The following will confirm your name only:

• passport – does not have to be issued in the UK
• bank or building society debit or credit card
• police warrant card
• armed forces identity card

2.2 Trailer plate design specification

A trailer registration plate is the same shape as the standard motorcycle plate and must have solid black characters (the letter and numbers) on a white background. The characters and the surface of the plate must not contain any designs, patterns or textures. Also:

• characters must be 64mm tall
• characters (except for the number ‘1’ or the letter ‘I’) must be 44mm wide
• the number ‘1’ and the letter ‘I’ must be 10mm wide
• the character stroke (the thickness of the black print) must be 10mm wide
• the space between the characters must be 10mm
• the vertical space between each row of characters must be 5mm
• the width of the margin between the top of the plate and any of the characters must be at least 5mm
• the width of the margin between the bottom of the plate and any of the characters must be at least 13mm

The characters must be in a standard font (style of lettering), for example:

The number plate must only show the registration number and the number plate manufacturer or supplier details (for example, the name, trademark or other way of identifying the plate’s manufacturer or supplier).

2.3 Where to display the trailer registration plates

The trailer registration plate must be displayed on the rear of the trailer in a visible and vertical position. It must be displayed as well as the towing vehicle’s registration plate and must be fixed as far as reasonably possible from this plate.

If the plate cannot be displayed at the rear of the trailer, a trailer registration plate must be fixed to both sides of the trailer so that they are both clearly visible.

2.4 UK stickers

As well as the trailer registration plate, some foreign countries may also require a UK sticker to be displayed on the trailer. To avoid any risk of enforcement action abroad, it is recommended that you display a UK sticker.

The sticker must not be displayed on the trailer registration plate. This should be a separate sticker or sign next to the trailer plate.

2.5 What to do if your trailer registration plate is stolen

If your plate is stolen, you should tell the police so that they can investigate.

2.6 If you no longer use the trailer for international journeys

If you are no longer using your trailer for international travel, you should tell DVLA using the online service. This is because the scheme does not apply to trailers that are only used in the UK. You should also remove the trailer registration plate after you have notified DVLA.

2.7 What to do if you sell, scrap or transfer your trailer

If you are no longer the keeper of a registered trailer you must tell DVLA through the online service.

You must also remove the trailer registration plate, but you should tell any new keeper what the registration number is. This is in case they wish to register as the trailer’s keeper so they can use it internationally in the future.