As per the Schedule of The Sale of Registration Marks Regulations 1995 (amended 2008)
Conditions for the assignment of a registration mark
10.—(1) A registration mark may not be assigned to a vehicle in pursuance of a relevant right unless the conditions specified in sub-paragraph (2) are satisfied.
(2) The conditions are that—
(a) where the relevant right is a right to assign a registration mark to a vehicle registered in the G.B. records, the assignment of the mark to the vehicle will not indicate that the vehicle was first used more recently than is the case
http://www.legislatio...95/2880/schedule/made
http://www.legislatio...72/regulation/11/made