Before towing a trailer, check two separate limits: what your driving licence permits and what the car is approved to tow. Passing one check does not satisfy the other. The licence test uses maximum authorised mass (MAM), while the vehicle’s towing capacity is a manufacturer limit that applies to the actual combination and loading.
For a standard Category B car licence, RSA guidance permits a trailer with a MAM of no more than 750kg. A heavier trailer may be used where the combined MAM of car and trailer does not exceed 3,500kg. If the combination falls outside those Category B conditions, the driver may need category BE. The precise entitlement depends on the licence category and codes shown on the licence; check the RSA category table rather than estimating from the trailer’s empty weight.
MAM is the maximum permitted loaded weight, not what the trailer happens to weigh on the day. A trailer carrying garden waste, machinery or a small car can be below its limit when empty and exceed it once loaded. Likewise, a car with a high tow rating does not grant the driver extra licence entitlement.
Use this order before a trip: read the car’s handbook and plate for its towing and nose-weight limits; read the trailer plate for its MAM; calculate the combined MAM for the licence rule; then check that the loaded trailer and actual car remain within the technical limits. Braking, tyres, lights and load restraint are separate safety checks. See How to Check a Car’s Towing Capacity for that second calculation.
