Reg Transfer & Change of owner


RMS Regular
Co. Down
Did a quick search before but most threads reference changes submitted via post or don't cover retention and change of owner together.

Is it advisable to wait for the new V5 when placing a reg on retention followed by a change of owner or is it ok to place a reg on retention then process the new owner change straight after using the same V5 reference number? i.e. selling a car with a reg you want to keep using the online services