Have you got a hire company sorted ? Some of them now will only hire above 3.5t to O licence holders as too many were coming back broken from private hires where the hirer had totally underestimated the difference between driving their Bippa van and a 7.5t box. Businesses hiring them too as private individuals, DVSA stopping & seizing etc. This happened to a “friend” 
got stopped by DVSA, who decided, correctly, (the row of plant pots with large cacti just behind the back door did not fool them for long 
) that he was carrying goods for his business, locked up the truck, passed him along the line to the police who did him for driving without insurance, because he took the hire company insurance for his “private move”. Had to go and hire a 3.5t, move all the stuff., in 3 loads and pay the hire company to collect the empty 7.5t. Sounds a bit severe but I suspect he failed the attitude test and needs grovelling lessons, in fact I am sure he would fail the attitude test