Csa/cms question

[Brandnewshit]

Hi my waste of space ex has recently moved in with a woman who has 2 kids aged 15 and 17, he is abusive and was v controlling, he knows im struggling with money, anyway hes been threatening for the 2 months hes known her and her kids and living with them to add her kids to the cms claim.
My question is the 17yr old turns 18 in august, will he still be able to add this one to the claim, i think she's been in college and her mum has been in reciept of child benefit, which i understand would mean that she would be applicable to be considered in the cms set up he has.
Surely whether shes in education or not, the day she turns 18 any eligibilty would end?

Anyone ?

No it goes up to age 20 if in A level equivalent education so college but not uni.

He can't add them? They're not his children?

Imthe child is included provided they’re under 20 and in secondary education.

There will be a reduction applied while there is eligibility for child benefit. This is based on academic year so if young person finishes studying in may/june/july,, child benefit applies until September.

Yes he can apply for a reduction in the maintenance amount he pays you if he's living with them. I believe it's up to when the child leaves full time education.

It's not when they leave full-time education. It ceases by the time the child is 20 and they cannot be considered if they are studying post-A level or equivalent.