Most people searching for a trailer MOT are about to discover that the thing they own does not have one. Ordinary trailers and caravans towed behind cars are not subject to periodic testing in the United Kingdom. Heavy trailers used commercially are, they are tested annually, and their records are held in the same national system as lorry and bus tests, which is why the search produces contradictory answers.
The line between the two
A trailer towed by a car, including a box trailer, a plant trailer, a horsebox on a car licence and a touring caravan, has no periodic test requirement. A trailer over the goods weight threshold used for commercial haulage does, and it is tested annually against the heavy vehicle standards. The distinction is about the class of the trailer and the use, not about how big it looks, and the operator of a commercial outfit will know which side of it they are on.
Where a tested trailer's record lives
Annual test results for heavy trailers, lorries, buses and coaches appear in the same GOV.UK vehicle test history and status service that covers cars, and it holds results from 2018 for those classes rather than 2005. Booking and certificates run through the DVSA vehicle testing route rather than through an MOT station. If you are buying a commercial trailer, the test history is a real record and is worth reading exactly as you would read a lorry's.
What replaces a test on an untested trailer
Nothing formal, which puts the whole burden on the owner. A trailer must still be in a roadworthy condition, its lights must work, its tyres must be legal and within their age tolerance for the load, the coupling and breakaway cable must be sound, and the brakes on a braked trailer must function. None of that is checked by anybody unless the police stop you or a DVSA roadside check does. The practical answer is an annual service on the same schedule a test would have imposed.
Buying a used trailer
Without a test history the checks are physical and documentary. Look at the chassis and drawbar for cracking, welded repairs and corrosion, check the tyre date codes rather than the tread, work the coupling and the brakes, and inspect the floor from underneath. Ask for a purchase invoice and, for anything valuable, check whether the trailer carries a security registration with one of the trailer marking schemes, because trailer theft is common and there is no DVLA record to trace one.
Questions people ask about mot trailer check
Does a car trailer need an MOT?
No. Ordinary trailers and caravans towed behind cars have no periodic test requirement in the United Kingdom, so there is no test record to look up.
Which trailers are tested annually?
Heavy goods trailers used commercially, which are tested against the heavy vehicle standards through the DVSA rather than at an MOT station.
Where do I find a tested trailer's history?
In the same GOV.UK vehicle test history service. Results for trailers, lorries, buses and coaches are held from 2018, rather than from 2005 as for cars.
How do I check a used trailer with no test history?
Physically. Chassis and drawbar condition, tyre age codes, coupling and breakaway cable, brakes and floor, plus paperwork and any security marking scheme registration.