High Income Child Benefit Charge - Panicking

[FigandHoney]

Hello I just found out that my husband's company car might mean that his salary was over 50k from April 2022 to April 2024. And that he should therefore have filed a tax self assessment.
I claim child benefits and ask him every year if his salary is over 50k. I explained to him that if it was over he would need to file a tax self assessment. But he clearly didn't listen to me properly and also didn't realise that his company car counted towards his income for this.
However he met someone yesterday through work who just got a bill for 8000£.
I am panicking at the thought of having to pay a similar amount or more.
Having looked it up his hybrid car benefit in kind adds over 10k to his income.
Based on this I used the calculator and we should have paid back just under 1000£ over those years. But using the fine calculator that goes up to 3000£ I think. And what I can't figure out is how the interest then works. How much could we be liable for?
Will we be able to pay this back in installments?
I am terrified.

Have you taken his pension contributions into account? Those get deducted from the salary figures used so depending how much he’s paid into his pension that will reduce the pay figure.

It’s on a sliding scale so unless his salary was over £60k for those tax years you won’t have to pay back all the child benefit e.g. if his salary after pension contributions is £55k for those years then you (he) will owe back half the CB.

The boundaries just went up so unlikely he is earning too much going forwards and by the time you took pension deductions out he may have still been within the limit to claim. Best ring the tax office and ask. Even if you do owe some it may be possible to pause the claim until the overpayment is repaid.