Child Support can be determined by a Child Support Agreement between parents or through a Child Support Assessment by the Child Support Agency.
Under a Binding Child Support Agreement, parents cannot vary the amount of Child Support agreed except by mutual agreement or by a Court Order. Each party must obtain independent legal representation for the purposes of drafting, agreeing, terminating or changing the terms of a Binding Child Support Agreement.
If you are not happy with a decision made by the Child Support Agency, it is possible to challenge the decision.