Under the Use of Invalid Carriages on the Highways Regulations 1988 invalid carriages are separated into 3 categories:
Manual wheelchairs, i.e. self-propelled or attendant propelled, not electrically propelled. These are not required to be registered with DVLA.
Powered wheelchairs and scooters – intended for footway use only with a maximum speed of 4mph and an unladen weight not exceeding 113.4kgs. These are not required to be registered with DVLA.
Mechanically propelled invalid carriages that are constructed or adapted to be capable of exceeding a speed of 4mph but incapable of exceeding a speed of 8mph on the level under its own power (generally powered wheelchairs and other outdoor vehicles including scooters intended for use on roads/highways). They must be fitted with a device capable of limiting the maximum speed to 4mph for use when travelling on footways. The unladen weight must not exceed 150kgs. These are required to be registered with DVLA.
Class 3 invalid carriages need to be registered for road use, be licensed in the "disabled" taxation class and display a nil duty tax disc. Unlike ordinary cars, invalid carriages do not need to provide evidence of VED exemption when licensing in the disabled class. Also, they are exempt from paying the first registration fee and are not required to display registration plates.
In order to register and license a class 3 invalid carriage the user will need to complete form V55/5 (for used vehicles) or V55/4 (for new vehicles) - and take or send it to their nearest DVLA local office (addresses can be found on the website at www.direct.gov.uk/motoringor in the V100 information leaflet which is available from post offices that issue tax discs or by telephoning 0870 243 0444 – you will need to quote your postcode). Evidence of the vehicle’s age (if available) will need to be submitted with the application together with documentation confirming the keeper’s name and address.
Although it is not a legal requirement, it is strongly advised to have insurance. Suitable schemes are not too expensive and are available to cover your personal safety, other people’s safety and the value of the vehicle.
Useful information for class 3 vehicle users can be found at the DfT Website