So OP said his sister had taken the plates off the car, so presumably the new owner is driving around with the old plates but it's actually still registered with the private plate? Sounds like it could be a bit of a mess for them as well!
I'd be interested to know how the new owner got it taxed and insured
Basically what she needs to do asap
Call insurance and tell them about her new/current plate so they can update her policy/car etc
Remove the wrong plates from her new car and put the ones she has declared to insurance on asap
Contact buyer of the car she just sold and tell him to expect a ticket and identify her as driver if it comes through
shes declared the "private" plate to insurance on her new car.
so she has declared she has moved the plate when she hasn't. therefore she doesn't have valid insurance.
she has sold the plate with the car. so she needs to ask if she can get it back.
what she needs to do is put the original plates back on her new car. then update insurance to normal plates. tell new owner of old car what has happened and ask if she can get old plate transferred to her new car.
if it's worth proper money they are within their rights to say your loss. if it's not worth anything and they don't like it they might agree. or she could offer to buy the plate off them.
Sorry to say but shes an idiot
Fill out the online form to put the plates n retention, costs £80
Call the insurance company with the original plates from new car and insure it properly.
Then if she wants to she can pay abother £80 to transfer the plates to the new car but id wait a few months for this complete and utter mess to blow over.
you only pay £80 once
There’s still the issue of the buyer surely, he/she is driving around on the wrong plates?
I think his sister the moron. Sold car with plates.
So new owner has it taxed and insured with the private plate.
Said moron thinks she can just print another plate and stick it on new car and it's now magically transferred over so insures under the private plate also.
Sister is most definitely lacking in brain cells. The new owner is fine. She will now try and steal the plate from them which will be interesting as that is theft and another law broken.