There was a new rule introduced a few months ago, where the postcode of the supplier of the plates has to be included on the bottom of the plate. Im not sure, but I think also that in order to get new plates made, say at Halfords or the local garage or dealer, you have to prove that you are the owner of that particular car, so probably have to show the V5 document. This rule was introduced to try to cut down the number of people buying and using false plates to carry out thefts, bank raids etc.
Compulsory:
Only one standard typeface will be legal — the Charles Wright Font.
Buyers of replacement plates will have to produce documentation proving they own the vehicle they are purchasing plates for.
The number plate of the seller must be marked with the name and postcode of the seller.
From 1 September any new number plates must carry the British Standard number: BS AU 145D.
Number plates must carry the name and identification of the number plate manufacturer.