New truck on trade plates, what license required?

[W124Bob]

Followed a clearly brand new chassis cab yesterday being delivered, I'm guessing for a body fitting. At what point does a lorry get plated. The truck in question was probably under 7.5tn so what would the minimum license requirement be. I assume that even an artic unit is under 7.5tn and in theory could be driven on a car license (with the grandfather rights to 7.5tn) before it is registered and taxed. I remember years ago seeing a bus chassis being driven down the road with nothing more than a box to sit on and a flying helmet for protection!

[W124Bob]

I thought there might be something about the fifth wheel.