What percentage of income can the CSA demand for arrears when maintenance is no longer due?

[Twinklemegan]

DH has large arrears built up through a combination of circumstances. His ex has reneged on an agreement to write off the arrears once his youngest left college. She is under the mistaken belief that he has a well paid job and is demanding more money.

If she went back to the CSA with this, what percentage of DH's income could they take? DH is earning £77 a week for a p/t job, £53 of which goes on childcare (which I understand they don't allow for ).

Nothing. Or that used to be the case. I lived with my dad along with 3 siblings, when 2 of them went to live with mum it meant a nil assessment for maintenance, and there was nothing for her to pay anymore. At this point she owed my dad thousands in arrears through the CSA. They said that as she had a nil assessment they could not get the arrears off her, told him that they can only claw back arrears on top of a payment, not the arrears only.

Well that's changed then