As someone who is in the know the vosa rule applies to any combination that exceeds or is capable of exceeding 3500 kg ie if the towing vehicle has a train weight of 4000kg and the combination as it is being used doesnt exceed 3500kg for example the trailer isnt loaded to its capacity.
Tachograph rules also apply as op licensing you will need a restricted op licence to move your own goods and a national op licence to move other peoples goods.You will fall into op licensing if there is any gain to be made ie entering a competion(even if you dont win!!) or someone getting you to move his car on the trailer for "fuel" money.
You dont need a cpc or transport manager for a restricted op licence but you do need money for maintenance needs per vehicle,a yard to park your vehicles and a maintenance contract.
Basically very complicated and can be expensive,dont fall foul of the "I didnt know policy" as it doesnt work both vosa and the police will issue fixed penalties inc points on your licence for overloading vehcile and trailer combinations,incorrect licence type if you passed your test after 1999 ( car licence).
Best answer dont put yourself into any situation where you will fall foul of the regulations.







