Millions of UK drivers remain unaware of a significant driving licence rule change, despite it having come into force nearly a year ago. From 10 June 2025, anyone holding a Category B driving licence—the most widely held type—is permitted to drive an electric or hydrogen-powered vehicle with a maximum authorised mass (MAM) of up to 4,250kg. Government stipulations add that the vehicle must be a zero emission vehicle. This additional weight allowance applies to vehicle types which can usually be driven using a category B licence and includes vehicles carrying up to eight passengers.
The standard MAM limit for petrol and diesel vehicles driven on a Category B licence stands at 3,500kg. However, if you passed your test before 1997 and hold a Category B licence, you are usually allowed to drive a vehicle and trailer combination up to 8,250kg MAM.
Additional Provisions for Disabled Passengers and Minibuses
Drivers are also permitted to operate a minibus towing a trailer exceeding 750kg MAM. Regarding the updated regulations, official guidance on Gov.uk states: "If the vehicle has additional specialist equipment to support disabled passengers, it can have a MAM of up to 5,000kg." The extra 750kg must be attributable to the specialist equipment. You can also drive an electric or hydrogen powered minibus up to 4,250kg MAM (5,000kg if fitted with additional specialist equipment for disabled passengers).
Towing Limits Under the New Rules
"You will be able to tow a trailer as long as the MAM of the vehicle and trailer combination does not exceed 7,000kg. For example, if your vehicle has a MAM of 4,250kg, then the MAM of your trailer will be limited to 2,750kg." The MAM of the trailer must never exceed 3,500kg. If you passed your category B driving test before January 1, 1997, you can drive vehicle and trailer combinations up to 8,250kg.
