Child Support Assessment
A child support assessment is the formal determination of how much child support is payable between parents. It usually comes from the standard formula applied by Services Australia, but it can also reflect agreed arrangements.
The assessment is the legal foundation of a child support liability and determines what is owed, how it is calculated, and how it can be enforced.
Definition
For the purposes of the CSRC Act, a child support assessment is an assessment made under the CSA Act. This includes administrative assessments (including where there is a departure in force such as a change of assessment) and assessments based on child support agreements.
A liability arising under a child support assessment is a registrable maintenance liability. For these purposes, a notional assessment is not a child support assessment.
Definition source: Guides to Social Policy Law, Child Support Guide, Version 4.97, released 20 March 2026, 1.1.C.70 Child support assessment.
Role in the formula
The child support assessment is the output of the system. It is the point where all inputs, adjustments, and rules come together to determine the child support to be paid.
In most cases, the assessment is an administrative assessment calculated using the child support formula. This combines both parents’ incomes, care percentages, and the number and ages of children to determine an annual rate.
A change of assessment can modify this result where special circumstances apply. This allows the Registrar to adjust the formula outcome to better reflect the real costs or financial situation.
Child support agreements can also form a child support assessment. These replace or override the formula with an agreed arrangement that is accepted under the legislation. Limited agreements must reflect at least the formula amount, while binding agreements can set different terms.
Once made, the assessment creates a registrable maintenance liability. This allows the amount to be collected and enforced, including through agency collection if required.
Example
Two parents have one child. Based on their incomes and care arrangements, the formula produces an annual child support amount of $8,000. This becomes their administrative assessment.
If one parent later applies for a change of assessment due to high medical costs, the amount may be increased. Alternatively, the parents may enter into a binding agreement that sets a different amount altogether. In each case, the resulting arrangement becomes the child support assessment.
Assessment notice
An assessment notice is the official record of your child support assessment. It shows the amount payable as both an annual and daily rate, along with the key details used in the calculation.
The notice confirms when the new rate starts and formally notifies both parents. This date is used for objections and reviews.