The DVLA rules vary, depending upon when you passed your driving test.
Drivers who passed their test before the 1st January 1997 normally have entitlement to drive vehicles between 3.5 tonnes and 7.5 tonnesGVW.
Drivers who passed their testafter the 1st January 1997will only have entitlement to drive a vehicle up to 3.5 tonnesGVW, which typically will be a standard Mercedes Sprinter.