After separation, the question of how to financially support the children is often one of the first that lands on the table, and one of the most stressful. Many parents are unsure what they are entitled to, what they have to pay or how it is even worked out.
The good news is that child support in Australia runs on a set formula, administered by the government, not negotiated from scratch by each family. The challenging news is that the formula does not always reflect what is happening in real life, and a few decisions early on can make a real difference to how smoothly things run.
Below we explain how child support works in Australia, how it is calculated, what it covers, how long it lasts and when it is worth getting legal advice.
What is child support in Australia?
Child support is a regular payment from one parent to the other to help cover the costs of raising their children after separation. It applies to both married and de facto parents and to children of same-sex relationships.
The system is set up under federal law and administered by Services Australia (formerly the Child Support Agency). The same rules apply across every state and territory, so it does not matter whether you are in NSW, Victoria or anywhere else in Australia.
How is child support calculated in Australia?
Australia uses an “income shares” model. The idea is that both parents should contribute to the costs of raising their children in proportion to their capacity to pay and to the time each parent has the children in their care.
Services Australia uses an eight-step formula that takes into account:
- Each parent’s adjusted taxable income.
- A self-support amount, deducted from each parent’s income before any calculation.
- The percentage of nights each parent has the child in their care.
- The age and number of children.
- A “costs of children” table set out in the legislation.
For most families, the parent with less care time pays the parent with more care, but that is not a hard rule. If the parent with more care also earns significantly more, payments can flow the other way.
You can model your own situation using the Services Australia child support estimator which uses the official formula.
How much is child support in Australia?
There is no single answer to “how much is child support in Australia”, because the amount depends on both parents’ incomes and the care arrangements. A few benchmarks are useful, though.
- Self-support amount: Each parent has a self-support amount deducted from their income before child support is calculated. For 2026 this is set at $31,046 per year, indexed annually.
- Minimum annual rate: Parents whose formula result would otherwise be very low may be assessed at the minimum annual rate, which is around $534 per year (2025 figure, indexed each year).
- Fixed annual rate: Parents on low incomes who are not on income support may be assessed at a fixed annual rate of around $1,768 per child, capped at three children.
- Income cap: Combined parental child support income is capped at 2.5 times Male Total Average Weekly Earnings (MTAWE). Income above that cap is not included in the formula.
These figures change each year, so always check Services Australia for the current rates.
What does child support cover (and not cover) in Australia?
Child support is designed to contribute to the everyday costs of raising children, including housing, food, clothing, utilities, transport, basic schooling expenses and routine medical care.
It is not specifically allocated to any one cost, and the parent receiving it does not have to account for how it is spent. That can be a source of frustration for paying parents, but the system is built on the assumption that the receiving parent is using it to support the household the children live in.
Some costs are commonly not covered by an ordinary child support assessment, including:
- Private school fees.
- Private health insurance for the children.
- Significant extracurricular activities.
- Out-of-pocket medical or orthodontic costs.
Where these costs are significant, parents can agree to cover them through a private child support agreement. They can also apply for a “change of assessment” on the basis of special circumstances.
How parents can arrange child support in Australia
There is more than one way to put child support in place. The right option depends on how much certainty you want and how cooperative the relationship is.
Administrative assessment by Services Australia
This is the default path. One parent applies for a child support assessment, Services Australia runs the formula and issues an assessment. Payments can either be collected privately between the parents or collected by Services Australia and passed on.
Private child support agreements
Parents can also formalise their own arrangements. There are two types:
- Limited child support agreements must reflect at least the amount in an existing assessment and can be ended after three years.
- Binding child support agreements are more flexible on amount but each parent must have independent legal advice before signing. These are typically used where one parent is paying more than the formula amount, or where the parents want long-term certainty.
Binding agreements are powerful, but they are very difficult to set aside later. Independent advice is required by law for a reason.
When does child support end in Australia?
Child support generally ends when a child turns 18. If the child is in their final year of secondary school when they turn 18, child support can be extended to the end of that school year, provided an application is made before the child’s 18th birthday.
Beyond that, separate orders for “adult child maintenance” may be available where a child has a disability or is undertaking tertiary study, but these are dealt with through the Federal Circuit and Family Court of Australia, not Services Australia.
What if your ex is not paying child support?
If child support is being collected by Services Australia and the paying parent falls behind, Services Australia has a range of enforcement powers, including:
- Deducting payments directly from wages.
- Intercepting tax refunds.
- Issuing a departure prohibition order to prevent the parent leaving Australia.
- Recovering arrears from bank accounts and other third parties.
If you have a private collection arrangement and payments stop, you can switch to “Services Australia collect” so that the agency takes over enforcement. Recovering long-standing arrears can be complex, particularly where the paying parent is self-employed, lives overseas or has hidden income, and this is one of the situations where legal advice is valuable.
When the child support formula does not reflect reality
The standard formula works well for parents on PAYG salaries. It is far less reliable where:
- One parent is self-employed and can influence their declared income.
- A parent receives significant income through a trust, company or investments.
- A parent lives overseas.
- A child has unusually high costs, such as private schooling or a disability.
- A parent has stopped working or significantly reduced hours without good reason.
In these situations, either parent can apply to Services Australia for a “change of assessment”, asking that the formula be departed from in special circumstances. If the parties cannot agree, the matter can move to court.
When to get legal advice on child support
Many parents can use the Services Australia system without ever needing a lawyer. Legal advice tends to be most valuable in a handful of situations:
- Negotiating or signing a binding child support agreement.
- Applying for, or responding to, a change of assessment.
- Dealing with arrears, enforcement or international issues.
- Where child support sits alongside property settlement or spousal maintenance issues that affect the overall financial picture.
Getting advice early often costs less than fixing a problem later.
Frequently asked questions about child support in Australia
Is child support mandatory in Australia?
Both parents have a legal duty to financially support their children. Child support is not optional in the sense that a parent can simply opt out, although parents can agree on their own arrangements rather than going through Services Australia.
Is child support taxable income?
No. Child support is not assessable income for the receiving parent, and it is not tax deductible for the paying parent.
How far back can child support be backdated in Australia?
A child support assessment generally starts from the date the application is received, although Services Australia can backdate up to 28 days in certain circumstances. Significant backdating beyond that is rare and usually requires special grounds.
Does inheritance affect child support in Australia?
Inheritance is not automatically included in child support income, but it can be relevant in a change of assessment if it produces income or is treated as a financial resource.
Can child support cover private school fees?
Not automatically. School fees and other significant costs can be addressed through a private child support agreement or, where parents cannot agree, through a change of assessment application.
Contact Allen Evans Family Lawyers for support
For most separated parents, the basic child support system in Australia is workable: an application to Services Australia, an assessment based on the formula and regular payments. The complications usually come at the edges, such as private agreements, change of assessment, arrears or where child support intersects with property and parenting matters. If you are also ending a marriage, see how the pieces fit together in our guide to the divorce process in Australia.
This information is for general purposes only and does not constitute legal advice. For advice specific to your situation, our experienced family lawyers can help you understand your position and your options.
If you or someone you know wants more information or needs help or advice, please contact us on 1300 110 080 or via our free enquiry form.