Is your campervan conversion legal? UK and US rules, checked October 2026

In the UK a DIY conversion becomes a “motor caravan” on the V5C when DVLA accepts four rigidly fixed internal features — seats and a table, a bed, cooking and storage — and a van that looks like a motor caravan from the outside; in the US there is no federal conversion step at all, and each state decides whether your van can be re-titled as a motor home. In both countries the weight limit printed on the van does not change because you built a kitchen in it, and that is the rule that catches most builds.

This is a summary of what the official pages say, not legal advice. Every rule below names the page it comes from, and I checked each one in October 2026. Where I could not find an official source for something people commonly repeat — gas certificates for private owners, for example — I say so instead of passing the claim on. I make a van layout planner, which is why the last part of this post is about where these rules land in a floor plan.

UK: changing the body type to motor caravan

DVLA's guidance Converting a vehicle into a motor caravan (gov.uk, updated 20 October 2026) sets out what DVLA expects before it changes the body type on your V5C. Inside, four categories of equipment must be rigidly fixed to the living compartment: seats and a table (the table may be easily removable), sleeping accommodation (which may be converted from the seats), cooking facilities, and storage facilities.

Outside, the body type “must describe what a vehicle looks like in traffic”. The guidance lists the external features commonly seen on motor caravans: two or more windows on at least one side of the main body (not counting the cab doors), a separate door into the living accommodation, and a high-top or pop-top elevating roof. A panel van with a fitted interior and no windows can meet every internal requirement and still keep its “panel van” description.

What changed in 2019. The older gov.uk page “Registering a DIY caravan” was cut back on 21 October 2019 to “only include the required internal features for motor caravans”; the same day DVLA first published the separate guidance above, which adds the external-appearance test (both change histories on gov.uk, checked October 2026). A UK Parliament petition from July 2019 records the background: from around May 2019 DVLA had been refusing reclassifications on the grounds that a vehicle “does not look like a motor caravan”. It closed with 623 signatures and no government response.

How to apply. Send the V5C (section 1 on the newer multi-coloured document, section 7 on the older one) with the V1006 motor caravan conversion checklist, interior photos of each feature with the bed and table in use, exterior photos from the front, both sides and the rear with the plates visible, and a photo of the VIN plate — each photo dated and labelled with the registration on the back — to DVLA, Swansea, SA99 1BA. DVLA may inspect the van; it pays for the inspection but not for getting the van there, and if the van can't be inspected the application is refused.

What a refusal means. Less than people think. The same guidance says the body type “should not affect the insurance category of the vehicle nor have any effect on speed limits or legislative requirements”, and that a van whose body type is not changed can still be used as a motor caravan if it meets the internal features. What stays with you either way: the alterations must not compromise safety, seats and seat belts used while travelling “must be securely mounted”, and you must be able to show the conversion was done safely if you later sell the van.

UK: weight, the 3,500 kg line and your licence

The gov.uk page Vehicle weights explained defines the maximum authorised mass (MAM, also called gross vehicle weight) as the weight of the vehicle including the maximum load it can carry safely, normally shown on a plate or sticker on the vehicle. A conversion does not raise it. The DVLA conversion guidance adds its own payload line: the converted vehicle should have enough payload — unladen weight subtracted from gross vehicle weight — to carry all its seated passengers, luggage and full water tanks without being overloaded. The same weights page says a vehicle that is unlikely to be used at its potential maximum weight may be “down-plated”, with the lower figure shown on the plate.

Your licence decides which side of 3,500 kg you can be on. On Driving licence categories, a category B licence from a test passed on or after 1 January 1997 covers petrol and diesel vehicles (hybrids included) up to 3,500 kg MAM, and electric or hydrogen vehicles up to 4,250 kg. Category C1 covers 3,500 to 7,500 kg. If you passed your car test before 1 January 1997, gov.uk's licence changes guidance says your licence already shows C1, C1E (8.25 tonnes), D1 and D1E, not for hire or reward. DVLA's fitness-to-drive guidance adds the catch: that entitlement lasts only until the licence expires or is revoked for medical reasons, and on renewal the higher Group 2 medical standards apply. C1 also cannot be renewed through the online over-70 service; it goes by post.

In practice that makes 3,500 kg a design limit, not just a number on the plate. A finished two-person build of about 600 kg plus the EN 1646-2 reserve for two people leaves a Fiat Ducato L3H2 about 650 kg free and a rear-wheel-drive Sprinter L3H2 about 330 kg, both on a 3,500 kg plate — every base van is ranked in which vans stay under 3,500 kg. Run your own van through the payload calculator before you buy materials.

UK: MOT and insurance

The gov.uk MOT fees table lists motor caravans in class 4 (maximum fee £54.85), alongside goods vehicles up to 3,000 kg design gross weight; goods vehicles over 3,000 kg up to 3,500 kg are class 7 (£58.60). The test is about the vehicle's roadworthiness; the habitation side of a conversion is not something the fees table describes, so I won't claim more than that.

On insurance there are two official facts. Third-party cover is the legal minimum, per gov.uk vehicle insurance; and the Consumer Insurance (Disclosure and Representations) Act 2012, section 2(2), makes it “the duty of the consumer to take reasonable care not to make a misrepresentation to the insurer”. A van insured as a panel van that is now a camper with a hob, a bed and a leisure battery is exactly the kind of change to tell your insurer about. Self-build motorhome policies exist; what evidence each insurer wants is their underwriting, not law, so ask before you finish — the DVLA photo set and checklist are a sensible pack to have ready either way.

Gas: I found no gov.uk page that requires a private owner of a self-built camper to hold a gas safety certificate, so I am not stating one. Insurers and buyers may still ask for it. What the locker itself has to look like — sealed from the living space, vented low through the floor — is in campervan gas locker rules.

US: no federal conversion step — your state decides

Titles and registrations in the US are issued by each state's motor vehicle agency — see USA.gov — and there is no federal registration for a camper conversion. Some states let you re-title a converted van as a motor home; the requirements differ. Two official examples, checked October 2026:

• Ohio — form BMV 3804, “Affidavit Conversion to Motor Home”: you swear, before a notary, that the equipment to qualify the vehicle as a motor home under Ohio Revised Code 4501.01(Q)(6)(b) is permanently installed — cold food storage (icebox or refrigerator), cooking (range top or oven), a place to eat (table with seating) and sleeping facilities (bed). You also agree not to remove it, and to re-title the vehicle if you do. (BMV 3804, 6/16 edition, as hosted by Clark County, Ohio.)
• Alaska — DMV Form 833, “Motorhome Conversion Affidavit”: four of five items must be present and permanently attached — cooking with refrigeration or an icebox; a self-contained or plumbed toilet; heating or air conditioning separate from the engine; a water supply with a sink and faucet; a 110/115 V system separate from the engine electrics, or an LP system. A DMV officer signs the inspection section. (Form 833, rev. 09/2013, dmv.alaska.gov.)

Note how different those are: Ohio never mentions a toilet, Alaska never mentions a bed. A layout that qualifies in one state can miss in another, so read your own state's DMV page before the interior is fixed. Insurance is the same story — whether an insurer writes a converted van as an RV is their decision, and there is no federal rule to quote.

The weight rating. Federal rule 49 CFR 567.4 puts the manufacturer's certification label on the hinge pillar, the door-latch post or the door edge that meets it — in practice the driver's door jamb — and requires it to show the GVWR and the GAWR of each axle, front to rear, in pounds. Those two numbers are the US version of the UK plate: the conversion has to fit inside the total and inside each axle.

Elsewhere in Europe

Germany, France, the Netherlands and Serbia each run their own process, and each has its own post in its own language: the TÜV inspection and “Wohnmobil” entry in camper-ausbau-tuev-zulassung, the French VASP homologation in homologation-vasp-fourgon-amenage, the RDW requirements in bus-ombouwen-tot-camper-eisen and Serbia's test-and-certificate route in registracija-kampera-u-srbiji.

Where the rules land in the floor plan

Read side by side, the official lists ask for the same handful of things, and almost all of them are layout decisions you make before the first cut:

The last row is the one no inspector can fix for you after the build. EN 1646-2, the European user-requirements standard for motor caravans, reserves 10 kg per metre of vehicle length, 10 kg per berth and 75 kg per passenger seat beyond the driver — the working is in the payload you have to leave empty and the full method in the camper van payload guide. In VanPlot the payload, axle split and centre of mass update as you place each item, and with the licence VanPlot AI (beta) will answer “how much payload is left, and what is the rear axle carrying?” from the same numbers — checking a layout with AI. None of that is an approval: the weighbridge and the agency in your country have the last word.

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