licences obtained before 1 January 1997
If you passed a car test before 1 January 1997 you keep your existing entitlement to tow trailers until your licence expires. This means you're generally entitled to drive a vehicle and trailer combination up to 8.25 tonnes maximum authorised mass (MAM). You also have entitlement to drive a minibus with a trailer over 750kgs MAM.

Car licences obtained on or after 1 January 1997
If you passed a car test on or after 1 January 1997 you're limited to vehicles up to 3.5 tonnes maximum authorised mass towing a trailer up to 750kgs, or a vehicle and trailer combination up to 3.5 tonnes MAM providing the MAM of the trailer doesn't exceed the unladen mass of the towing vehicle. You will need to pass an additional driving test in B+E if you wish to tow a caravan or trailer combination which exceeds these weight limits.

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