u/Effective-Pumpkin763

Hi, I bought a private reg through a transfer company and they’ve asked me to assign it to my vehicle first. I don’t actually want to use the private plate on the car as im currently looking for a new car — I just want it on retention.
Can I assign the reg to my vehicle and then immediately transfer it back to the original registration/put it on retention without physically changing the number plates?
Also, would I need to notify my insurer if the private reg is only assigned temporarily?