Child support assessment

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Child support assessment

If you cannot reach agreement about child support, either parent can apply to the Services Australia (Child Support) for an assessment to work out how much should be paid.

The Services Australia uses a ‘formula assessment’ to work out how much child support is paid. 

The amount of child support that you pay or receive may also affect your Family Tax Benefit.

If you disagree with a child support decision get legal advice.

How the assessment is made

In making their assessment, Services Australia looks at:

  • both parents’ income
  • if you are supporting other children
  • the costs of raising children (including their ages and the number of children)
  • how much time you spend with the children (your ‘levels of care’).

The amount of child support you get or have to pay is based on these and other factors.

To apply go to the Services Australia (Child Support) website.

Parents’ income

The costs of the children are shared by both parents. Services Australia (Child Support) works out these costs by combining both parents’ income.

Each parent has a ‘self-support amount’ deducted from their income before the calculations are done. The parent with the higher income is responsible for providing the greater share of the children’s costs.

Late or non lodgement of tax returns

Do your tax returns every year. Services Australia and the Australian Taxation Office share their records. If you do not lodge a tax return, you can be assessed to pay child support based ona provisional income determined by Services Australia. If you or the other parent lodge a tax return late, your child support assessment for past years may change. You may have paid or received the incorrect amount of child support.

If you have a child support debt, contact Services Australia on 131 272 to ask if the past child support assessments can be adjusted. If they are not able to, get legal advice about further action to reduce the debt.

If you are owed child support, contact Services Australia on 131 272 to ask if they can collect the arrears. If they are not able to, get legal advice about further action to enforce the arrears.

Application by non-parent carer

If you look after the children but are not their parent, you can apply to Services Australia for child support. Get legal advice.

Supporting other children

It is important that Services Australia (Child Support) knows if you have other children of your own living with you. If you do, your income used to calculate your child support responsibilities may be reduced and you may pay less child support.

If you have stepchildren, your stepchild’s parents are responsible for supporting them. In special circumstances you can apply to have your assessment reviewed. Get legal advice.

Costs of raising children

The amount of care you and the other parent provide for the children can be recognised as meeting some or all of the costs of the children.

Some of the children’s costs can be met directly through looking after your children, and the rest will be paid or received as child support.

Levels of care

The table below explains how much of your child support responsibilities are met directly through looking after your children.

Nights per year the children spend with you

Nights per fortnight

Words Services Australia use to describe level of care

Amount of child support met through direct care of your children

0–51 nights

1 night

‘Below regular care’


52–127 nights

2–4 nights

‘Regular care’


128–175 nights

5–6 nights

‘Shared care’

25% plus 2% for every percentage point over 35%

176–189 nights

7 nights

‘Shared care’


190–237 nights

8–9 nights

‘Shared care’

51% plus 2% for every percentage point over 53%

238–313 nights

10–12 nights

‘Primary care’


314–365 nights

13–14 nights

‘Above primary care’


If you care for the children 52 nights or more each year and are receiving a Centrelink benefit you may not have to pay child support. This is because you are meeting your share of the children’s costs by looking after them.

If you change the amount of time you care for the children, your child support may also change. This is because your share of the children’s costs may vary depending on how much time you look after them.

You should keep a diary of when the children are in your care.

You must tell Services Australia as soon as your childcare arrangements change.

Child support, Family Tax Benefit and your child care levels

Services Australia (Child Support) and Centrelink now use the same rules to determine the percentage of care for each parent. Whether it is Centrelink or Services Australia that first makes a care decision, the other agency will automatically use the same percentage.

Disagree with a decision

If you think that the amount of child support Services Australia (Child Support) have decided upon is not correct or fair, get legal advice quickly. There are ways to change an assessment. You can object to Child Support decisions.

More information

Child support agreements

Child support payments

Family Tax Benefit and child support

Adult child maintenance for over-18s

Proving who the dad is

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