Child support is its own system
Child support is administered by Services Australia under a legislated formula. It is not decided by the family courts, and it is separate from both parenting orders and property settlement.
Having one does not resolve the others. Parents regularly assume a property settlement deals with child support, or that a parenting order fixes the payment. Neither is true — though the parenting arrangement does directly affect the assessment, as below.
How the formula works
In outline, the assessment works through these steps:
- Each parent's child support income is worked out from taxable income
- A self-support amount is deducted from each
- The remaining incomes are combined
- The costs of the children are determined from combined income and their ages
- Each parent's income percentage is calculated
- Care percentage is converted to a cost percentage
- The difference determines who pays and how much
Because it works from taxable income, the formula can produce outcomes that do not reflect reality — particularly where a parent is self-employed, has income through a company or trust, or has recently reduced their hours. That is what the change of assessment process exists for.
Care percentage drives everything
The proportion of nights each parent cares for the children feeds directly into the assessment, so changing a parenting arrangement changes the child support outcome automatically.
This has two practical consequences. First, care arrangements should be recorded accurately and reported, because an assessment based on the wrong care percentage produces the wrong figure. Second, and less comfortably, care disputes and money disputes become entangled — a parent seeking more time may be doing so for entirely good reasons, but the financial effect is real and both parents know it.
Where care actually changes, notify Services Australia. Where the recorded percentage is wrong, it can be corrected, but generally not retrospectively for long periods.
Agreements instead of an assessment
| Binding agreement | Limited agreement | |
|---|---|---|
| Legal advice required? | Yes, both parties, independently | No |
| Amount | Any amount, above or below the assessment | Must be at least the assessed amount |
| Ending it | Difficult — by agreement or court order | Can be ended after 3 years or on a significant income change |
| Suits | Certainty, non-cash arrangements, complex incomes | Simpler situations, shorter horizons |
Binding agreements can cover non-cash contributions — school fees, health insurance, a mortgage payment — which the formula does not accommodate. That flexibility is their advantage. Their disadvantage is that they are hard to escape if circumstances change, which is precisely why independent advice is mandatory.
Changing an assessment
A change of assessment can be sought where the formula produces an unjust result in the particular circumstances. The grounds are defined, and include:
- High costs of spending time with the child
- Special needs of the child
- Costs of caring for another person
- The child's own income or property
- Income, property or financial resources not reflected in taxable income
- The parent's capacity to earn being understated
- High childcare costs
- Necessary commitments to support themselves
The ground most often used against a self-employed parent is that their taxable income does not reflect their real financial resources. Establishing it requires evidence — company and trust records, lifestyle evidence, and often an accountant — not merely an assertion.
Adult child maintenance
Child support generally ends when a child turns 18 or finishes school, but the family courts can order adult child maintenance in two situations: where it is necessary to enable the child to complete their education, or because of a mental or physical disability.
This is genuinely a family court matter rather than a Services Australia one, and applications should ideally be brought before the child turns 18 where the need is already apparent.
What it costs
- Fixed fee for advice on an assessment
- Fixed fee for a binding agreement, per party
- Change of assessment applications quoted
- Stage estimates for court applications
- Coordinated with property and parenting matters
- Costs agreed with you before we start
Frequently asked questions
Services Australia applies a legislated formula: each parent's child support income is worked out from taxable income, a self-support amount is deducted, incomes are combined, the costs of the children are determined from combined income and ages, and each parent's income percentage is compared with their care percentage. The difference determines who pays and how much.
Yes, automatically. The percentage of nights each parent cares for the children feeds directly into the assessment. If care actually changes you should notify Services Australia, because an assessment based on the wrong care percentage produces the wrong figure and corrections are generally not made retrospectively for long periods.
You can apply for a change of assessment on the ground that a parent's income, property or financial resources are not reflected in their taxable income, or that their capacity to earn is understated. Establishing it requires evidence — company and trust records, lifestyle evidence and often an accountant — rather than assertion.
A binding agreement requires both parties to obtain independent legal advice, can be for any amount above or below the assessment, and is difficult to end. A limited agreement does not require legal advice but must be for at least the assessed amount, and can be ended after three years or on a significant change in income.
Generally yes, when the child turns 18 or finishes school. The family courts can order adult child maintenance in two situations: where it is necessary to enable the child to complete their education, or because of a mental or physical disability. That is a court matter rather than a Services Australia one.
More information
Child Support matters are not straight forward and are often emotionally-charged. Our advice can help clarify your situation early and save you stress.
Rockhampton child support & adult child maintenance lawyers
Child support payments are payments made by one or both parents to cover the costs of caring for the child/children (usually until they finish high school or turn 18).
Commonly parents apply for child support through Services Australia (previously the Child Support Agency and the Department of Human Services). Services Australia issues child support assessments using a legislated formula.
Depending on your unique circumstances, it may be advantageous to enter into a private child support agreement with your former partner (being either a “Limited Child Support Agreement” or a “Binding Child Support Agreement”). These types of agreements can provide for the payment of additional expenses such as medical and extra-curricular activities. Our Rockhampton family lawyers are experienced at drafting such agreements to ensure they are legally binding and enforceable.
Start your family law matter online — privately and at your own pace
Not quite ready to pick up the phone? You can begin online instead. Answer a few simple questions about your situation in your own time, and our experienced family lawyers will review your details before your first appointment — so your meeting is focused on you, not paperwork.
You should also contact us for legal advice if:
- Concerns have surfaced about the identity of the child’s biological parent (including DNA testing or providing proof of paternity)
- Your ex-husband or wife lives outside of Australia.
- You are a carer parent and have concerns about child support or child maintenance issues (including Services Australia decisions)
- You are a liable (paying) parent and have questions about child support or child maintenance issues (including Services Australia decisions)
- You don’t understand or disagree with changes to your child support assessment.
We can also advise you on the circumstances in which Adult Child Maintenance may apply for children over the age of 18 years. The Family Law Act does give the Court the power to make such Orders on a case by case basis.
We can also help with:
- Separation and Divorce
- Property Settlements for both married and de facto couples
- Property disputes involving parents and adult children
- Spouse maintenance
- Financial agreements (pre-nups)
- Parenting Arrangements
- Personal protection issues involving domestic violence
- Mediation
- Surrogacy agreements
Flexible Legal Financing for Family Law Matters
South Geldard Lawyers has proudly partnered with JustFund to offer our clients greater financial independence, particularly through family law litigation funding. For some clients, it can be a struggle to afford legal fees and disbursements, and limited access to funding sometimes means the settlement process stalls and clients get stuck. This partnership enables our clients to access the legal assistance they deserve to settle their family law matters and move on with their lives without the burden of immediate financial constraints.
Extensive Experience
Our professional team has extensive experience in a wide range of legal areas. Our approach is one of planning and involvement. We will continue to be there to support you with accurate and timely advice.
This page is general information about the law as it applies in Queensland, current as at 2026. It is not legal advice and does not take your circumstances into account. Figures set by regulation are indexed and change. Speak to one of our lawyers before acting.