In short
Services Australia works out child support using a formula set by law, based on both parents' incomes, how many nights each parent has the children, and the children's number and ages. Applying for an assessment is free. The minimum rate is $551 a year in 2026, and support usually ends when the child turns 18.
How is child support calculated?
Services Australia calculates child support using a formula set by law. It's based on:
- both parents' incomes (after a self-support amount, which is $31,046 in 2026)
- how many nights each parent has the children
- the number and ages of the children, and the cost of raising them at your combined income
Each parent's share of the costs is weighed against their share of care. The parent whose income share is higher than their care share pays the difference. Services Australia has a free online estimator.
How care affects the amount
| Nights a year | Care | Level of care |
|---|---|---|
| 0 to 51 | 0 to 13% | Less than regular care |
| 52 to 127 | 14 to 34% | Regular care |
| 128 to 237 | 35 to 65% | Shared care |
| 238 to 313 | 66 to 86% | Primary care |
| 314 to 365 | 87 to 100% | More than primary care |
What are your child support options?
You can get an assessment from Services Australia, make a limited agreement, or make a Binding Child Support Agreement.
Assessment
Apply to Services Australia through myGov or by phone. They calculate the amount using the formula. You can have them collect it (Child Support Collect) or arrange payments between yourselves (Private Collect).
Limited agreement
An assessment must already be in place, and you agree to at least the assessed amount. It can include things like school fees. No lawyer is required. Either parent can end it after 3 years.
Binding Child Support Agreement. You can agree to any amount - more or less than the formula - and include things like school fees or health insurance. It gives you certainty, but both parents must get independent legal advice and a signed lawyer's certificate, or it isn't valid. It can generally only be ended by a new binding agreement or a court order.
Do I need to apply for child support if I get Family Tax Benefit?
To get more than the base rate of Family Tax Benefit Part A, you generally need to apply for child support within 91 days of separating (or of a change in care). Exemptions are available, for example if you fear family violence.
Can I change a child support assessment?
You can ask Services Australia to change an assessment if one of 10 special circumstances applies - for example, high costs of seeing the children, a child's special needs, private school fees both parents agreed to, or the other parent's real earning capacity. Being unhappy with the amount isn't enough on its own.
If you disagree with a decision, you can object within 28 days of the letter. After that, you can apply to the Administrative Review Tribunal within 28 days of the objection decision.
At what age does child support end?
Usually when the child turns 18. If they're still at school full time, the receiving parent can extend it to the end of the school year, but must apply while the child is still 17. Support for an adult child at university or with a disability needs a separate court application.
How does ezysplit help with child support?
Rachel explains your options and gets it started.
- Tell Rachel your situationRachel explains how the formula is likely to apply to you, and whether a free assessment or an agreement makes more sense.
- Want certainty? Go bindingIf you and the other parent want to set your own amount, your lawyer advises you and drafts the Binding Child Support Agreement. The other parent must get their own lawyer.
- Your lawyer's certificateYour lawyer signs the certificate the law requires, so the agreement is valid.
- Tie it togetherChild support often goes hand in hand with parenting and property arrangements. Rachel makes sure they line up.
Frequently asked questions
How much child support will I pay or get?
It depends on both parents' incomes, how many nights each of you has the children, and their number and ages. The formula is set by law, and Services Australia has a free online estimator.
What's the minimum child support in 2026?
$551 a year. It applies to paying parents on low incomes who have the children fewer than 52 nights a year.
Do I need a lawyer to get child support?
Not for an assessment - you apply directly to Services Australia. You do need a lawyer for a binding child support agreement. Both of you must get your own independent legal advice and a signed lawyer's certificate, or the agreement isn't valid.
What's the difference between a limited and a binding agreement?
A limited agreement needs an assessment already in place, must be at least the assessed amount, needs no lawyer and can be ended after 3 years. A binding agreement can be any amount, needs legal advice for both of you, and can generally only be ended by a new binding agreement or a court order.
Can child support be changed if my situation is unusual?
Yes, if you can show one of 10 special circumstances, such as high costs of seeing the children, a child's special needs or agreed private school fees. You apply to Services Australia, and the other parent can see and respond to your application.
What if I disagree with a decision?
Lodge an objection within 28 days of getting the letter. If you're still unhappy, you can apply to the Administrative Review Tribunal within 28 days of the objection decision.
When does child support stop?
Usually when your child turns 18. If they're at school full time, the receiving parent can extend it to the end of the school year, but must apply while the child is 17. Support for university or a disability after that needs a court order.
Can consent orders cover child support?
No. Child support is handled through Services Australia or a child support agreement, not family law consent orders.
Sources checked 19 October 2026: Services Australia - Who can get an assessment · Services Australia - Basic formula · Services Australia - 2026 formula values · Services Australia - Binding agreements · Services Australia - Limited agreements · Services Australia - Special circumstances · Services Australia - Objections · Services Australia - When your child turns 18 · Services Australia - FTB and child support