To import a motorhome into the UK permanently you’ll need to register it.
The size of motorhomes is restricted in the UK - you can’t register one more than 12 metres long and 2.55 metres wide.
The measurements don’t include driving mirrors, rear bumpers, lamps, or reflectors.
There’s no height limit, but if the motorhome is over 3 metres tall you must have a notice showing the height where the driver can see it.