A child support departure order, also called a change of assessment, is a formal way to vary your child support when the standard formula gives an unfair result, and you start it by applying to Services Australia or, in harder cases, to a court. Most child support in Australia is worked out with a formula that looks at both parents' incomes and how much time each of you spends with the children. Sometimes that formula does not fit real life. The law lets you depart from it, but only for specific reasons and only if you follow the right process.
Key Points
- 10 legal reasons. You must prove at least one of the 10 grounds listed in section 117 of the Child Support (Assessment) Act 1989 to change an assessment.
- Two routes. Most people apply for an administrative change of assessment through Services Australia under Part 6A, section 98B. Harder cases go to court for a departure order under Part 7, sections 116 to 118.
- Time limits. An assessment more than 18 months old needs the court's permission under sections 111 and 112, and one older than 7 years generally cannot be changed.
- Cost. Applying through Services Australia is free. Going to court means filing fees and, usually, legal costs.
What is a child support departure order?
A child support departure order is a decision that changes the annual amount of child support you pay or receive, departing from the standard formula. There are two ways to get one.
The first is the administrative change of assessment, decided by the Services Australia Registrar. Section 98B of the Child Support (Assessment) Act 1989 is the rule that lets a parent ask the Registrar to look at the assessment again when special circumstances exist. This is the common route, and it sits in Part 6A of the Act. You would use it for most situations, such as one parent earning far more than their tax return shows, or a child with high medical costs.
The second is a court departure order, made by a judge. This lives in Part 7 of the Act, sections 116 to 118. Section 116 sets out when you are allowed to apply straight to a court instead of Services Australia. Section 117 lists what the court must be satisfied about before it changes anything. Section 118 says what orders the judge can actually make, such as changing the income figure used in the formula or fixing a set dollar amount. You would use the court route when you are already in court over property or parenting, or when the money side is genuinely complex.
What are the reasons you can ask to change a child support assessment?
You cannot change an assessment just because you dislike the amount. You have to prove one of 10 reasons. These are the grounds for departure in section 117 of the Act. When the Registrar decides an administrative change, section 98C requires the same grounds to be met. Section 117 is the legal backbone for any change.
- High costs of spending time with the child. Your travel or communication costs to see your child come to more than 5% of your adjusted taxable income.
- The child has special needs. Extra costs from a physical, mental or learning disability, or from a special talent or ability.
- Care, education or training both parents intended. Costs are higher because the child is being raised or schooled the way both of you planned, for example a private school.
- The child has their own resources. The child has significant income, earning capacity or property.
- You already provided money or property for the child. You have paid or transferred money or assets for the child's benefit outside the assessment.
- High childcare costs. For a child under 12, childcare costs that come to more than 5% of your income.
- Your necessary living or work commitments. Essential costs that genuinely cut your capacity to pay.
- The assessed income understates real capacity. A parent's true income, property or financial resources are higher than the formula shows.
- A duty to maintain someone else. A legal duty to support another child or person reduces a parent's capacity to pay.
- Responsibility for a resident child. Your capacity to support the child in the assessment is reduced because you also support a resident child, a child who lives with you but is not legally your own.
What are the steps to apply for a change of assessment?
An administrative change of assessment usually takes around 90 days from start to decision. You move through a set sequence so both parents get a say.
Change of Assessment Process
| # | Stage | Timeframe | Notes |
|---|---|---|---|
| 1 | Call the enquiry line | Before you apply | Phone the Child Support enquiry line to check this is the right process for you |
| 2 | Lodge form CS1970 | At your pace | Complete the Application to change your assessment (CS1970) and attach your evidence |
| 3 | Other parent is notified | Within days | Services Australia sends the other parent a copy of your application |
| 4 | Other parent responds | About 14 days | The other parent uses form CS1971 to agree or put their own case |
| 5 | Senior Case Officer reviews | 60 to 90 days | A Senior Case Officer weighs the facts under section 98C and may phone both parents |
| 6 | Decision issued | End of review | You get a written notice saying whether the rate changed and why |
| 7 | Object if you disagree | Within 28 days | Lodge form CS1893 for an internal review of the decision |
| 8 | Apply to the ART | After the objection | If the objection fails, apply to the Administrative Review Tribunal |
Section 98B is the rule that lets you ask for this administrative review in the first place. If the assessment you want to change is more than 18 months old, the door is harder to open. Sections 111 and 112 apply here. Section 111 is the part that makes you ask a court for permission before touching an old assessment. Section 112 gives the court power to grant that permission, but only if you have a real reason for the delay and can show hardship. Once an assessment is more than 7 years old, you generally cannot change it at all.
If you go the court route instead, you skip the Services Australia forms and file in court under sections 116 to 118. Section 116 sets out when you can apply directly, and section 118 gives the judge the power to override the Registrar's formula with a specific order.
What documents and evidence do you need?
Whether your application succeeds comes down largely to your evidence, so gather it before you lodge. The material falls into two groups.
Required for every application:
- The CS1970 form. The official application where you pick your reasons and explain what is going on.
- Your full financial details. A complete picture of your income, assets and debts.
- Proof of income. Usually your latest tax return plus recent payslips.
- A copy of the current assessment. The starting figure you are asking to change.
Additional for special cases:
- Evidence of the other parent's real finances. For the reason about understated income, records of their assets, lifestyle or business earnings.
- Documentation of the child's special needs. Medical reports, a diagnosis letter or specialist invoices.
- Receipts and invoices. For high contact costs, records of flights, fuel or accommodation.
- Private school enrolment signed by both parents. To show the schooling was a shared intention.
What does it cost and how long does it take?
The Services Australia change of assessment is free, while the court route costs money. There is no fee to lodge form CS1970, and no fee to object with form CS1893. If your objection fails and you go to the Administrative Review Tribunal, the first review is usually free, though a second-level review may carry a fee.
A court departure order is different. You will normally pay a court filing fee to start, and if you use a lawyer, legal costs can easily run into the tens of thousands. Time differs too. Services Australia aims to finish a review within about 90 days, but a court case can take many months, sometimes more than a year, to reach a final hearing.
If you want to see how these reasons play out in real disputes over debts, inheritance and private school fees, read Child Support: Debts, Inheritance and Private School Fees. If you would rather settle child support in a single payment, see When Do Australian Courts Order Lump Sum Child Support? and What Is a Child Support Trust? Lump Sum Payments in Australia (2026).
FAQ
Can I backdate a change of assessment? Yes, within limits. A change can apply to past periods, but if the period is more than 18 months ago you first need the court's permission under section 112, and you must explain why you waited so long to apply.
What if the other parent is hiding income? Use the reason about understated income, backed by section 117. You will need evidence that their real finances are higher than the formula shows, such as property records, business earnings, or proof they are deliberately earning less than they can.
Can I change an assessment that is several years old? You can try for one between 18 months and 7 years old, but it is hard. Section 111 makes you apply to a court for leave first, and section 112 means the court weighs your reason for the delay and whether refusing would cause you real hardship. Anything older than 7 years generally cannot be changed.
Is going to court better than applying through Services Australia? For most people, no. Services Australia is free and faster. Section 116 lets you go to court when the situation is too complex for a Senior Case Officer, for example a complicated business structure, or when you are already in court over property or parenting and want it all decided together.
