I'm not sure about the size of actual plate, the yellow plate size, but all figures and letters are supposed to be as follows, so I'm guessing all figures have to fit within the dimensions given, once in place the yellow plate can be as large or as small as you wish, it's the black letters and numbers that must be of certain size etc.
MOTORCYCLES AND TRICYCLES

  • Motorcycles and tricycles registered after 1.9.2001 must only display a number plate at the rear of the vehicle.
  • Motorcycles and tricycles registered before 1.9.2001 can display a number plate at the front but are not required to.
  • The characters may be smaller e.g.

Character Height 64mm
Character Width 44mm
Character Stroke 10mm
Space between characters 10mm
Space between groups 30mm
Top, side & bottom margin 11mm
Space between vertical lines 13mm


  • Motorcycles registered on or after 1 September 2001 must display a two-line number plate number plate. Motorcycles registered prior to the 1 September 2001 may display a three-line plate, but one-line plates are illegal, irrespective of the date of registration of the motorcycle.