If you have a personalised number plate assigned to your car, then when it comes to the time you wish to sell the vehicle, you will have to apply to put the private plate on retention.
Putting a private number plate on retention will allow you to keep hold of the plate whilst you find another car to put it on, or enable you to sell the plate on.
The fee to put a plate on retention was reduced in March 2015 from £105 to £80 as DVLA have removed the £25 charge that was in place to renew the retention of the plate on an annual basis. DVLA have also now removed the charge to add or amend nominee details which means the how retention process can be carried out a lot quicker by DVLA.
Once you have put a number plate on retention, you will receive your new V5 detailing the new reg number assigned to the vehicle and a copy of the retention certificate.