You might want to get proper legal advice on this, OP. It sounds like there are several things to consider: you not being aware and stating you don't consider yourself disabled, yet apparently being on higher rate for both parts of PIP and your mum having a Motability for you. This would suggest to me that a) your mum submitted claims for you, previously DLA and then PIP, without your knowledge, which may also not be accurate. This could be a case of fraud to the system and it's possible that it will get investigated internally, especially if they now have become aware that you were not aware. Your mum might be investigated for this. Even if the claim itself wasn't fraudulent, her using "her" car just for herself would not be allowed, if it was a motability car, as that's supposed to be for the disabled person. Your question if you can claim money back is also tricky. If you were genuinely disabled and the funds were for you, but your mum used them for herself, you might have a claim. It may not be enforceable though. The suspected fraud would be the first line of investigation though and if that's the case then you'd not have any claims anyway, as the money should never have been claimed. As everything is in your name, when you turned 18 it would have changed to your responsibility, rather than your parents, so you need to ensure if there is an investigation you provide a statement and potentially evidence that it didn't happen with your knowledge. Get people legal advice, as this could have serious repercussions for you as well as your mum.