Laws on 3.5 Tonne Truck Car Movements

ROG:

Big burner:
If you have Class 1 entitlement you are better off using a braked 3.5t trailer behind a 4x4 that should give you a payload of about 2.5t and you can carry all the tools and passengers you want as well.

That brings it over the 3.5 tonnes MAM so into the EU tacho regs unless an exemption applies

Yes you would need a tacho fitting, but you would be exempt from needing an O Licence

Technically since 2010 any vehicle used for “hire and reward” with a GTW over 3.5t fitted with a tow bar requires a tacho to be fitted regardless of whether it has a trailer. I’m not sure if there has ever been any prosecutions though.