Child Support Assessment Process

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Child support stems from the fundamental principle that “each parent of a child has a duty to maintain their child.”

Where parents are separated, either the mother or the father can apply to the Department of Human Services (Child Support) (“the CSA”) for a child support assessment.

This assessment is the process that the CSA take in order to ascertain what each parent is either entitled to or liable to pay.

The CSA have adopted a formula in order to calculate the amount of child support payable.


The child support formula

The formula is based largely on the income of each parent and the level of care they have for the child the subject of the assessment.

The process is summarised as follows:-

1)  Each parent’s ‘child support income’ is calculated.  This is calculated by ascertaining each parent’s taxable income and deducting a ‘self-support’ amount.  This is an amount determined by the CSA that is required to support yourself.  Currently the self-support amount is $23,610 (as at 2015).  Once this figure is deducted from a parent’s taxable income, this is called your ‘child support income’.

 2) Both parent’s child support incomes are added together to reach a combined child support income figure.

 3) Each parent’s individual child support income is then divided by the combined figure to reach an income percentage.

 4) Each parent’s ‘care percentage’ is then calculated.  This is calculated with reference to a table.  For instance, if the child spends time with each parent on a shared care basis (equal time) then each parent’s care percentage will be 50%.  If the child spends most of the time living with one parent and minimal time with the other, the care percentage for the first parent may be 87%.  The CSA determine this care percentage by reference to the amount of overnight time the child spends with each parent.

 5) Each parent’s ‘cost percentage’ is then calculated with reference to a table.  This is calculated by reference to the parent’s combined child support income and the age and number of children that are being considered.  For example, where the parents have a combined child support income of $97,299.00 to $129,730.00, one child will be given the cost percentage of $14,271.00 plus 10c for every dollar over $97,299.00.

6) The costs percentage is then subtracted from the income percentage for each parent.  This then gives a figure which is called the ‘child support percentage’.  Where the percentage is negative, that parent will be assessed to receive child support.  Where the percentage is positive, that parent will be assessed to pay child support.

 7) The costs for each child is then calculated according to a table with reference to the parent’s combined child support income.

 8) The child support assessment then provides a final figure of child support payable by multiplying the positive child support percentage by the costs percentage.

 Although this formula seems complicated, the process involved in applying for an assessment to the Child Support Agency is relatively straight-forward.


Further information about the child support assessment process, including a useful child support assessment calculator, is also available on the CSA’s website.

Still have more questions on the Child Support Assessment process, contact us

If you would like more information on the Child Support Assessment process, our Brisbane Family Lawyers can help. Call us on Ph 07 3252 0011 or email us today to ask about a fixed fee first appointment.