Wrongly claimed child benefit

[ZanyTealBiscuit]

Hi, I'm asking on behalf of my partner. He has had full custody of his son for 7+ years now due to courts decision. He has recently applied for child benefit for him but it seems his ex is still claiming child benefit for his son even though she no longer has custody of him or is able to see him. What's going to happen? As he had a letter from HMRC asking to provide the dates of when he was fully living with him. He has proof with court papers and everything, will she have to repay the wrongly claimed child benefit? As I'm pretty sure its classed as benefit fraud.

Yes she will

She can claim child benefit (even if he wasn’t living with her), providing she contributed to the cost of providing for the child at a rate of not less than the weekly rate of Child Benefit payable for that child. Now your partner has claimed, it will be awarded to him as his son lives with him (priority order)

If she was contributing then, she will have a recoverable overpayment of child benefit as she was not entitled

She didn't contribute anything, she has 3 other child that have all been taken off of her also. He recieved no child maintenance or anything. She went off radar due to drug issues.

Why is he only claiming now?

Its to do with housing and he never thought about doing it before.