Both parents have a continuing obligation to financially support their children even though the parents and their children will no longer be living together as a family.
Parents can agree on how they will do this in the changed circumstances. But if agreement cannot be reached, either parent can apply to Inland Revenue Child Support for what is called a Formula Assessment of child support. This assessment works out how much one parent needs to pay the other having regard to their respective incomes, and the amount of nights the children are in their care.
Your likely Formula Assessment can be calculated by visiting the www.ird.govt.nz website. The benefit of an annual Formula Assessment rather than an Agreement is its flexibility, as the needs of the children and the resources of their parents change over time.
A Formula Assessment may not work in your circumstances, perhaps because even though the paying parent has plenty of money, a low taxable income is used in the formula. There is an Administrative Review process to change a formula assessment in such situations.
In some situations a Family Court Judge can decide how much child support is appropriate.