When you purchase a personalised registration the £80 transfer fee is included in the purchase price. This is also shown on the V750 certificate of entitlement and covers the future transfer of the registration to a vehicle. When you want to remove the registration from a vehicle the transfer fee of £80 is again payable, you can then either assign the registration to another vehicle at no further cost or put it on retention for use at a future date and you will be issued with a V778 retention certificate.
The V778 retention certificate will show that the transfer fee £80 has been paid so there will be no further transfer cost when you come to assign it to a vehicle in the future. Both the V750 certificate of entitlement and the V778 retention certificate are valid for 10 years, however they can be renewed at no cost for another 10 years on an ongoing basis, meaning that the registration does not have to be used within the initial 10 year period.