To think I shouldn't be responsible for this full debt?

[AutomaticSteeple]

I have received a letter from HMRC regarding an over payment of tax credits from 4 years ago. This was an old claim with my ex husband, at the time my claim immediately changed to a single claim.Any apparent over payment would have been paid to him as the sole earner, I was a SAHM. I called tax credits saying surely I should only need to pay half the balance as it was a joint claim, they said no. They will chase us both for the full balance until it is clear, whoever first.

Ex dp has refused to pay anything towards it, so it's all left to me. Does anyone know what the law is on this? They have also requested the balance in full, nearly 1k.

Keep disputing it. In the end they’ll accept half as it’s better than nothing. Dp just had this from him “lovely” ex who continued claiming as if he were there otherwise she’d have had to find a job he’s paid off his half and heard no more

I had this and made it clear, I'll pay my half only and they can chase my ex for his half. I paid it £10 a month for 5 years. No idea if my ex ever paid his half.

Refuse to pay, and point out that it would cause you hardship, whereas your ex is able to pay it. (if that's true)
If you are still on tax credits you will probably have to agree some kind of repayment plan, otherwise push it till they threaten to take you to court and then offer a token monthly payment if that's all you can afford.

Legally as you are jointly and severally liable they can pursue either of you for all of it.

The one then paying would be able to seek the 50% share from the other (ie. there is an implied indemnity).

However as people have said above if you speak to them they may agree to accept 50% from you but please make sure that the wording of any letter makes it clear that they are accepting the 50% in full settlement of any claim they may have against you in this regard.

Does the ex work at all because they could adjust his tax code for his "share"?

Thank you for all the comments. I will definitely try writing to them and offer half. Yes ex works full time so he shouldn't get away with paying nothing