COMMERCIAL trailers over 750kg and all trailers over 3,500kg must be registered before towing them through most mainland European countries to comply with road traffic regulations.
This means that trailers making international and EU journeys must display their own registration plate (separate from the vehicle towing them) and have a trailer registration certificate that can be shown to a foreign authority on request.
Hauliers do not need to register trailers that are only used in the UK and Ireland.