NotSpaghetti
Chewbacca I have done that for my other son and daughter as "backup" but my American resident son only has a US license now as his UK one is expired. They would not put him on in the same way.
Maybe some companies accept overseas licences.
I insured my car for my sister, who lives in the US, to drive it when she visited me at Christmas. She has never held a UK licence having learnt to drive in the US. I do have an automatic car so I don’t know if that made a difference, I don’t think I would have trusted her in a manual one!
I can’t remember how much I paid, about £25 I think.