From the UK Government website:

If you ride a motorbike or motor tricycle

Motorcycles and motor tricycles registered on or after 1 September 2001 must only display a number plate at the rear of the vehicle.

If you ride a motorbike or motor tricycle registered before 1 September 2001 you can also display a number plate at the front, but you don’t have to.

Motorcycle and motor tricycle number plate numbers should be on 2 lines.

So let's get all those front plates off laugh2

https://www.gov.uk/displaying-number-plates/rules-number-plates

Red Leader drive