Not 100% true
I had a bike which was cat c .
I sent off for the log book which I got
6 months later the police contacted me to do the Vic test which was free

I am lead to understand that if I requested for the Vic test first then I would have to pay.

And they didn't really do much on the test
Other than wave a machine around looking for tags/chips
Then moaned that it had a day light mot ( no lights ) lol