I'm all over this thread! to add my twopenneth to the NRP partner mention:-
My partner has zero disposable income after his very average outgoings and he pays more than the CSA recommended level.
His ex gets child tax credits, child benefit of course and both children are now secondary school age. She works 2.5 days a week and youngest often arrives for a weekend at his dads lacking the basic essentials that he needs, e.g. trousers two inches too short in the winter, no jumpers in the winter, shoes too small, hair is never cut.
Bearing in mind that my partner has zero disposable income I find it hilarious that his ex has recently had a sizeable improvement made to her house. Whilst all the time telling her children that they should ask their dad for what I consider essentials.
I've made it very clear to my partner that my earnings go towards all treats, holidays, meals out, cinema trips etc, I also like to buy occasional treats for the two children as I love them to bits. I think its important that he continues to pay for his children as much as he can until they hit 18 and then he can pay support them directly.
Interestingly though, recently the ex who sits in her huge house with no real need or desire to work full time to provide for her children has called for a CSA review. My partner was livid and I told him I would be embarassed if I was in her shoes. She's an educated woman, with every capability to work full time and set a good example to her children and instead she has naively thought that she can get her hands on more money for nothing because I've appeared in the past 18 months.