Not sure how this applies to yours? Get a quote for my motorhome import and we will tell you before you spend anything.
What is the legal maximum width for a motorhome in the UK?
Regulation 8 of the Road Vehicles (Construction and Use) Regulations 1986 sets 2.55 metres for "any other motor vehicle". That is the category a motorhome falls into. Refrigerated vehicles get 2.60 metres, and an RV is not a fridge on wheels, however well stocked the fridge.
This matters because an American RV is built for American roads, not UK ones, so the UK figure is the one to check against.
How is overall width measured?
This is the part almost nobody explains, and it is where RV buyers get caught out. Regulation 3 defines "overall width" as the distance between the outermost points on each side of the vehicle, inclusive of all parts of the vehicle and "any fitting on, or attached to, the vehicle", with a list of exceptions.
The exceptions that matter for a motorhome are:
- any driving mirror
- any lamp or reflector fitted in accordance with the Lighting Regulations
- the bulge of the tyres caused by the vehicle's weight
The rest of the list covers things like snow ploughs, customs seals, sheeting over a load and railway fittings, which is unlikely to be your problem on a campsite in Devon.
In plain terms: if it is fitted to the RV and it is not on that list, the definition includes it. You may read on forums that awnings, grab handles or window rubbers "don't count". The regulation does not list them as exceptions. Our advice is simple: measure the RV with everything fitted, at the widest point, and do not rely on a brochure figure for the bare body.
Send us the details before you pay. We tell you what the import involves, then handle the customs, the NOVA and the DVLA paperwork.
How long can a motorhome be in the UK?
Regulation 7 sets a maximum length of 12 metres for "a wheeled motor vehicle other than a bus". A motorhome is not a bus, so 12 metres is your limit.
If you are looking at one of the longer coaches, measure it rather than trusting the advert. The same regulation also sets separate, longer limits for a vehicle towing a trailer, so if you plan to tow a car behind the RV, the combination has its own rules and it is worth checking that too before you commit.
Does the approval test use the same numbers?
Not necessarily. An American RV first registered outside Europe goes to DVSA for vehicle approval before it can be registered here, unless it is old enough to be exempt (our guide to importing an American RV explains the route). The approval test has its own rules on masses and dimensions, and they are not written in exactly the same way as the Construction and Use limits for driving on the road.
We will not pretend there is a neat one-line answer for an RV that sits right on the edge. If the RV you are looking at measures close to 2.55m, send us the model and its specification before you buy, and we will check that specific model rather than guess.
What should I check before I buy an American RV?
A short list that saves a lot of grief:
- Ask for the manufacturer's specification sheet for that exact model and year, with overall width and length.
- Measure it yourself, or have the seller measure it, at the widest point with the awning, handles and any add-ons fitted. Mirrors and lamps can be left out of the figure; almost everything else is in.
- Check the length with anything fitted at the back, such as a ladder, bike rack or spare wheel carrier.
- Look at the weight plate. If the plated maximum weight is over 3,500kg, that changes the licence you need, the speed limits and the road tax.
- Think about where you will use it. Being legal at 2.55m does not make a single-track lane in the Lake District any wider. That one is a tip, not a law.
What about weight and my driving licence?
Width and length are only half the size question. The other half is weight. A standard car licence (category B, test passed from 1 January 1997) covers vehicles up to 3,500kg maximum authorised mass. Above that you need category C1, which covers 3,500 to 7,500kg. If you passed your car test before 1 January 1997 you usually hold C1 already, but check your licence.
Weight also changes speed limits, road tax and some London charges. We cover all of that in the guide to motorhomes over 3,500kg.
What we do for you
We handle the paperwork side of importing an American RV: the customs import declaration, working out and paying the import VAT and duty, the NOVA notification to HMRC, and preparing the DVLA first registration pack, including filling in the V55/5 for you to sign and post. We obtain the documents DVLA may need to date the vehicle, and if you need it we arrange transport to the UK. We do not carry out approval tests or modifications: a garage or converter does those, and we handle the paperwork around them. Before you buy, send us the model and its dimensions and we will tell you what the import involves.
Quick answers
Do wing mirrors count in the width of a motorhome?
No. Regulation 3 of the Construction and Use Regulations excludes "any driving mirror" from overall width. Lamps and reflectors fitted under the Lighting Regulations are also excluded.
Does an awning count towards the 2.55m width?
The legal definition includes any fitting on or attached to the vehicle, and awnings are not on the list of exceptions. Measure the RV with the awning fitted and work from that figure.
Is 12 metres the limit for every motorhome?
Twelve metres is the limit in regulation 7 for a wheeled motor vehicle other than a bus, which covers a motorhome. Towing a trailer or car brings a separate combination limit.
My RV is 2.59m wide. Can I still import it?
That is a question for the specific model, not a general rule. Send us the specification before you buy and we will check how that vehicle is treated.
Where do I find my RV's weight?
On the manufacturer's plate. The licence rules use the maximum authorised mass shown there, not what the RV weighs on the day.
Official sources, checked on 27 September 2026: legislation.gov.uk/uksi/1986/1078/regulation/8; legislation.gov.uk/uksi/1986/1078/regulation/7; legislation.gov.uk/uksi/1986/1078/regulation/3; legislation.gov.uk/uksi/2020/818; assets.publishing.service.gov.uk/media/61f7d351e90e0768a3523237/application-for-gb-conversion-iva-motor-homes.pdf; gov.uk/driving-licence-categories; gov.uk/old-driving-licence-categories; gov.uk/speed-limits; gov.uk/vehicle-tax-rate-tables/rates-for-motorhomes.