Tania Sakla Family Lawyer Sydney

Tania Sakla - Family Lawyer

Tania is an experienced and passionate family lawyer Sydney based. And at the core of Tania’s approach to family law matters is the aspiration to preserve relationships and to avoid…
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Learn more about child support in Australia with our extensive expert guide

If your relationship has broken down, you may face a number of family law issues including spousal maintenance and property division. But if you have children, there are other special considerations, all focused on their wellbeing and needs.

One of the central family law principles is that the best interests of the child are paramount

Child support plays a crucial role in ensuring the best interests of the child can be maintained, especially after separation. Child support aims to ensure there are financial means available to meet the child’s needs and expenses throughout their development. This is especially important when there’s a significant difference in the parents’ income and earning potential.

This expert guide covers child support law in Australia and how it may apply to situations like yours.

Family supporting children

Child support in Australia: what is it?

In Australia, child support is the financial support for children after the parents’ relationship ends. Both parents have a responsibility to support their children until the age of 18 and sometimes beyond.

Dominic Nguyen, Solicitor Director, Unified Lawyers

It does not matter whether the parents were married or in a de facto relationship before separation. Nor does it matter if the relationship was same-sex or opposite-sex. If there are children of the relationship, Australian family law requires that the children’s best interests are the top priority. In many cases, this means that child support is payable by one or both parents. 

What does child support cover?

There isn’t much information about what child support payments should cover, however they operate as a contribution to the totality of the child’s expenses. As parents, you’re expected to agree on expenses, including:

  • Medical costs
  • School fees,
  • School uniforms
  • Sports and dance activities
  • Music lessons

However, if there’s a communication breakdown, you may find it impossible to agree with the other parent.

The child support system allows the paying parent to pay up to 30 percent of the child support amount by directly paying expenses, for example, by paying fees directly to the school. Such payments are only for recognised expenses including:

  • Rent
  • Transport
  • School fees
  • School uniforms
  • Medical expenses

If you and the other parent can’t agree on what child support should cover, you may need legal advice or family counselling.


Greg and Andras were de facto partners for 12 years. Six months ago, their relationship broke down, and they separated.

They have two children: eight-year-old Isabella and six-year-old Lucia. The children attend a private school and participate in various after school activities, including karate, tennis, music lessons, circus skills and surf lifesaving.

Greg earns a much higher income than Andras. Andras has applied for child support, as he is the primary carer of the children. Greg pays school fees directly to the school and wants this included in the child support assessment. He would also like the children’s after-school activities to be reviewed and reduced.

To minimise disruption to the children, Andras would like their after-school activities to remain unchanged.

Greg and Andras agree to attend family counselling to explore possible solutions.  

How do I apply for child support?

Child Support Agency

If you’re a parent of the child, you can apply to the Child Support Agency (CSA) for child support by filling out an online application form. CSA is part of the Commonwealth Government’s Department of Human Services.

You will need to provide personal details, including:

  • The full names of your children
  • Your full name and the full name of the other parent
  • Contact information such as mailing and email addresses and phone numbers for you and the other parent
  • Your government identification numbers, for example, your Centrelink Reference Number (CRN) and your Tax File Number (TFN)
  • Details about how much you earn and how much you’re likely to earn in the future
  • Details of all the people who depend on you for financial support, including details about how often they’re in your care
  • Your bank account information   

Once you’ve submitted your application, CSA will work out whether child support is payable and calculate how much. This is known as a child support assessment.

CSA will then collect and manage the payments, setting up automatic deductions and deposits to minimise the risk of non-payment.

For many parents, the advantage of using this system is that CSA completely manages it, removing the stress of:

  • Negotiating an agreement
  • Monitoring payments
  • Chasing late payments
  • Enforcing non-payments

If your situation is complicated, you may need legal advice before submitting the form. Such situations may include:

  • Domestic violence
  • Complex financial or business arrangements
  • Paternity issues
  • Children with special needs
  • Possible child abuse

We recommend that you seek legal advice from your community legal service or a private lawyer.

Private agreements

The Federal Circuit and Family Court of Australia have very limited jurisdiction to hear child support applications, and is not involved in the assessment or calculation of these payments. However the court can order child support the payment to occur or cease in certain circumstances such if the child is over the age of 18. For example, some adult children need further support to complete secondary or tertiary study or while they’re establishing an independent income.

In some circumstances, you may be able to make a private child support agreement with the other parent. These agreements are helpful when the parents agree that the needs, wellbeing and lifestyle of the child are beyond what can be assessed by the CSA, and so instead decide to privately stipulate child support. Some agreements can be worked out by the parents (and their lawyers), while others may be based on a CSA assessment. Whether a private agreement is appropriate depends on the circumstances. Private agreements can last for a long time, so you need to make sure you’ve considered whether:

  • Any circumstances may change
  • The agreement looks after your child’s future needs

These things are difficult to predict. We recommend that you seek legal advice from a private lawyer or community legal service centre.

Who can apply for child support in Australia?

There are two broad categories of people who can apply for child support in Australia: parents and non-parent carers.


As a parent, you can apply for child support if you can prove that you’re the child’s legal parent. Proof may include:

  • A statutory declaration
  • Your name on the child’s birth certificate
  • Your name on the child’s adoption papers
  • Your marriage certificate
  • A Court declaration

In some circumstances, there may be questions about the identity of the child’s father. These issues are known as paternity or parentage issues. Paternity issues may arise when you wish to claim child support from the child’s father, but he denies being the father.

In specific circumstances, other laws may say that you’re a parent. For example, the law may say that you’re the child’s father if you’re a male and you lived with the mother immediately before or during her pregnancy (up to 20 weeks pregnant).

Non-parent carers

The law allows non-parent carers to apply for child support in specific circumstances.

Non-parent carers include:

If you’re a blood relative, you need to prove that you are related to the child. You may need legal help to work out how to do this.

If you’re a legal guardian (and not the child’s blood relative), you need to satisfy criteria including:

  • How long the child spends in your care
  • Whether you’re in a relationship with one of the child’s parents
  • Whether you share joint care with either parent
  • Whether your care is in the best interests of the child

For more information, see our Child Support Guide or the Services Australia information page for non-parent carers.

When is child support legally owed?

Payments managed by CSA

Child support is legally owed on the first payment due date after CSA completes the child support assessment and sets up its collection schedule.

Private agreements

Whether your collection arrangements are private or through CSA, child support is legally owed from the due date of the first agreed payment. For any debts, you can ask CSA to recover payments up to three months outstanding.

You may anticipate difficulty making child support payments, such as a change in your financial circumstances that affects your income. In such situations, you should seek legal advice as soon as possible.

How is child support paid?

If you have a child support assessment from CSA, you and the other parent can decide whether to ask CSA to collect the child support, or make private collection arrangements.  

Because CSA can only enforce registered child support assessments, you should not agree to a private collection arrangement unless you’re confident that regular payments will be made. We recommend that you seek legal advice if you’re considering this type of arrangement. 

In circumstances where CSA is to collect the child support, it will set up a system to collect the money from the other parent’s employer, bank accounts, government benefits or even tax refunds.

When does child support end?

It’s common for child support to end when your child reaches adulthood. That is, when they turn 18 years old.

Child support may extend after the age of 18, for reasons such as:

  • The child hasn’t yet completed secondary study, university study, or another form of higher education
  • The child needs more time to establish themselves in the workforce
  • The child has significant ongoing health or medical needs which require extra financial support

If there are reasons why your child’s support should be extended, you need to make a private agreement with the other parent. However, you must apply before the child’s 18th birthday. If you’re concerned about whether the other parent will comply with the agreement, you should seek legal advice about methods of enforcement.  


Jessie is 17 years old. He will turn 18 during his final year of school. Jessie’s parents Della and Pedro divorced five years ago. Since that time, CSA has collected child support from Della and paid it to Pedro.

Pedro is concerned that child support will end when Jessie turns 18 years old, interrupting Jessie’s education. Pedro can’t afford to pay the school fees without child support. Jessie would also like to study teaching at university. Pedro wants an extension of child support to help Jessie complete his tertiary education.

With the help of his community legal service, Pedro makes a child maintenance agreement with Della. The agreement will commence on Jessie’s 18th birthday and end on his 21st birthday. They decide to apply for consent orders based on the agreement.

What happens if we can’t agree on child support payments?

If you’re unsuccessfully trying to negotiate child support payments with the other parent, you can apply to CSA for a child support assessment.

You may need to apply for court orders if you can’t agree on maintenance payments for an adult child.

We recommend seeking legal advice if you’re trying to negotiate an agreement or thinking about applying for a court order.

Child support formula: how to calculate

Calculation of child support is a complicated process, which considers your current financial circumstances and the child’s future needs. Child support assessments are different in every situation

CSA will take a detailed look at your financial situations, including:

  • Incomes
  • Expenses
  • Future earning potential
  • Which parent is responsible for each of the child’s expenses
  • How much time the children spend with each parent
  • Any parenting plans or court orders relating to the children
  • The children’s ages  

When CSA has all the information, it applies an eight-step formula to work out child support.

CSA will determine if you should:

  • Pay child support if the time you spend caring for your children is less than your share of your combined income with the other parent; or
  • Receive child support if the time you spend caring for your children is more than your share of your combined income with the other parent

If you disagree with an assessment, you usually have 28 days to appeal. Details about how to appeal are included with the assessment notification, which CSA sends to you.

Child support formula

Analysing parents’ incomes

CSA’s website provides detailed information about how parents’ incomes are analysed for child support assessments.

CSA uses the taxable income of both parents to determine the appropriate payment amount. The CSA will consider a range of other factors for parents who live in other countries or on Norfolk Island.

If your income changes, you need to tell CSA as soon as possible. In most cases, CSA can’t backdate any additional payments.

CSA’s website has a handy child support calculator, which can help you estimate how much child support may apply to your situation.

Checking the cost of children

The cost of children is taken into account when calculating child support, for example:

  • How many children need child support
  • Whether you have other dependent children from a different relationship
  • Whether you have other child support assessments
  • Whether any dependent children live with you for at least 128 nights per year
  • Whether the other parent has any other dependent children
  • Whether the other parent has other child support assessments
  • Details about how you and the other parent care for the child
  • Details about how you and the other parent pay for expenses such as school fees and after-school activities
  • Other information about your dependent children, for example, special medical needs

You may need to provide supporting documents, for example:

  • A diary or calendar showing when the child is in your care
  • Tax returns
  • Other child support assessments
  • Any relevant court orders or parenting plans 
  • Invoices and receipts for expenses such as school fees, activities and medical expenses
  • Doctor’s reports (or reports from other health professionals) detailing the child’s needs and any ongoing care requirements
  • Statements from other people about the level of care you provide to your child

The Services Australia website has more information about level of care and child support.

Calculating income share

When working out child support, CSA will give equal consideration to each parent’s income. It does not take into account any income from non-parent carers, such as grandparents.

To work out your income (and the other parent’s income), CSA will consider the following for both of you:

  • Taxable incomes
  • Reportable fringe benefits
  • Total net investment loss
  • Tax-free pensions and benefits
  • Foreign incomes
  • Superannuation contributions
  • Any income support payments

It will compare this information against the level of care provided by both parents and arrive at an assessment amount.

For more information about calculating income share, see the Services Australia website.

calculating income share

Taking cost shares into consideration

A significant part of the assessment process is working out the care and cost percentage. The care percentage represents how much time a parent spends caring for the child. The cost percentage represents a parent’s share of the child’s expenses.

The cost percentage takes into account:

  • The combined child support income
  • The number of children needing child support
  • The ages of the children

The costs are divided between the parents depending on their percentage of the combined income.


Douglas is ten years old. His father Florian has applied for a child support assessment through CSA. Douglas spends eight nights per fortnight in Florian’s care. He spends six nights per fortnight in his mother Annabel’s care.

Florian’s cost percentage is calculated as 51 percent, representing the share of the costs that Florian meets directly through caring for Douglas.

CSA will consider this in the child support assessment for Douglas.

Final child support calculation: how much child support will I have to pay?

The final child support calculation will differ in every situation.

At their most basic, child support assessments are based on care requirements, expenses and income. Based on these criteria, you can use the Australian Governments’ Child Support Estimator to calculate an approximate amount.

We recommend seeking legal advice from a private lawyer or community legal service for more information about child support.

More FAQs about child support in Australia

Is it possible to legally avoid paying child support?

Child support assessments

If you disagree with your child support assessment, you can challenge it using CSA’s dispute process. It’s the only way you can legally avoid paying child support when CSA is involved.

Usually, you have 28 days to lodge a dispute with CSA from the day you receive the decision letter about your assessment. You can only lodge a dispute for specific reasons, including:

  • The assessment is based on incorrect or outdated information
  • CSA hasn’t considered all the facts and circumstances
  • CSA hasn’t considered some critical details
  • CSA has incorrectly applied the law to the assessment

If you wish to object for some other reason, you may need to apply to a court to review the decision. Such reasons may include:

  • Parentage
  • Collection of child support payments
  • Permission to travel overseas with the child (if there is a prohibition order in place)

CSA may review the assessment (or refuse to review the assessment) and let you know of its decision. If you disagree, there are some limited circumstances in which you can apply to the Administrative Appeals Tribunal (AAT).

You have 28 days to apply to the AAT from the date you receive your letter advising of CSA’s review decision. In rare circumstances, you can appeal to a court if you disagree with the AAT’s decision.

If you’re considering an appeal or review, seek legal advice.

Private arrangements

If you have a CSA assessment but a private collection arrangement, you can ask CSA to recover unpaid child support if it’s three or more months overdue.

If you disagree with the assessment, you must apply to CSA for a change or review. In the meantime, you must continue to pay the assessed child support.

For private registered agreements, a parent can apply to the FCA or FCC to enforce the payment if the other parent stops or reduces child support payments.

If you need to change your child support agreement, you must make a new agreement with the other parent. You must continue to pay child support while negotiating the new agreement. Breaching a court order can have serious penalties.

If you have a child support agreement, the other parent may choose to take legal action against you for breach of contract if you stop paying. If successful, they may be able to recover the amount of unpaid child support.

If you need to make new child support arrangements, you should seek legal advice. You must continue to pay the agreed amount of child support while you’re waiting to make new arrangements.

How can I minimise child support payments?

If you have a change in circumstances, you can ask CSA to review your child support. For example:

  • You lost your job
  • Your income has significantly reduced
  • Your expenses have significantly increased (for example, you have other dependent children)
  • The other parent’s income significantly increased
  • The child has turned 18 years old and now can earn an income
  • You have paid child support in different ways, for example, transferring money or property to the other parent or a grandparent for the child

There are also reasons to increase child support payments, for example:

  • The costs of the child’s care are higher than expected due to special needs
  • The costs of the child’s schooling are higher than expected
  • The costs of spending time with the child have increased (for example, because the child now lives further away from a parent)

For more information, see the Services Australia information on changing your assessment in special circumstances.

How far back can I claim child support?

If the other parent has stopped or reduced child support, you can ask CSA to collect the debt. However, in most circumstances, CSA can only collect the debt for the previous three months.

Sometimes, you may need your child support assessment amended due to a change in circumstances. CSA can backdate the amendment, but only for the previous 18 months. You may be able to apply for a court order to amend an assessment, but these situations are rare. A court can backdate an assessment up to seven years.

In both these situations, you need to apply to CSA as soon as you become aware of an issue.

Can I change my child support payments?

In limited circumstances, you can change your child support payments. For more information, see How can I minimise child support payments?.

How does child support affect my Centrelink or Government benefits?

There’s a close link between child support and government benefits (including Centrelink benefits). Child support payments can affect your Family Tax Benefit.

In some situations, if you don’t apply for child support payments, Centrelink may reduce your Family Tax Benefit payments to the minimum rate.

For more information, see the Services Australia website.

Takeaway Points

Child support is complex. We recommend seeking legal advice to explore all the risks, issues and legal consequences.

For CSA assessments, you need to show evidence for everything you claim, and to act quickly if circumstances change.

It’s important to understand that child support in Australia is meant to serve the best interests of your children.  

Tania Sakla Family Lawyer Sydney

Tania Sakla - Family Lawyer

Tania is an experienced and passionate family lawyer Sydney based. And at the core of Tania’s approach to family law matters is the aspiration to preserve relationships and to avoid dragging her client’s through a drawn out and emotionally tolling family law dispute. Where she can, Tania will always attempt to resolve her client’s matter through settlement negotiations without compromising her client’s rights and entitlements under the law.

“All materials throughout this entire website has been prepared by Unified Lawyers for informational purposes only. All materials throughout this entire website are not legal advice and should not be interpreted as legal advice. We do not guarantee that any of the information on this website is current or correct.

You should seek specialist legal advice or other professional advice about your specific circumstances.
All information on this site is not intended to create, and receipt of it does not constitute a lawyer-client relationship between you and Unified lawyers.

Information on this site is not updated regularly and so may not be up to date.”