Private plates.......again

[garycab]

I have just sold a car without an mot or taxed, been SORN for a year. Because of this I couldn't take the plates off, the new owner has said once they get it all sorted he will let me know so I can go ahead and apply to remove them and put back to the originals.
Now as the logbook will be in their name is this going to cause problems? How would I go about it ? Thanks.