Victoria Legal Aid

Child support assessment

The Services Australia (Child Support) uses the child support assessment to work out your payment.

Either parent, or a non-parent carer or other relative caring for the children, can apply to Services Australia (Child Support) for child support and an assessment to work out how much should be paid.

To find out how the assessment is made and to apply for child support, go to the Services Australia (Child Support)External Link website. Services Australia uses a ‘formula assessment’ to work out how much child support is paid.

Find out your estimated child supportExternal Link . The amount of child support that you get may also affect your Family Tax Benefit.

To work out the amount of child support that should be paid, Services Australia (Child Support) will look at:

  • each parent’s income and their combined income
  • how much time each parent cares for the child (level or percentage of care)
  • the child’s age
  • if a parent has biological or adopted children from past and new families (in the case of stepchildren, a court order is required to be provided).

Levels or percentage of care

This table 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 spend looking after them.

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

If you cannot agree on level or percentage of care, you may have to provide relevant documents to confirm patterns of care. These may include court orders, parenting plans, childcare centre and school documents, records of children’s regular activities, visits to health care and other services, or reports from government departments.

You must tell Services Australia as soon as your care arrangements change or if a written agreement is not being followed.

Child support, Family Tax Benefit and your percentage of care

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 Child Support that first makes a care decision, the other agency will automatically use the same percentage.

Change of circumstances

Tell Services Australia immediately if there are changes in your circumstancesExternal Link that could affect your child support. This is important, because some changes cannot be backdated. This includes any changes to you or the other parent’s contact details, income, relationship status, or the children and care arrangements.

If you do not tell Services Australia, you might:

  • pay the wrong amount of child support and owe money (debt) or pay too much (overpayment)
  • get the incorrect child support amount (underpayment or overpayment).

Child support debts and overpayments have to be paid back.

Changing your assessment in special circumstances

If you think that you have special circumstances that make your child support assessment unfair, you can apply to change your assessment. There are 10 reasons to apply for a change of assessmentExternal Link . Any decision to change an assessment must be fair ('just and equitable') and the impact on government pensions and benefits has to be considered (‘otherwise proper').

When applying for a change of assessment, the financial circumstances of both parents is relevant. This includes 'income, property and financial resources'. Both parents have an obligation to make a full and complete disclosure of their financial circumstances.

To request a change, complete the Change of assessment in special circumstancesExternal Link form.

Attach copies of relevant court orders, receipts and/or documents. Services Australia (Child Support) can ask for more information if they need it.

More information

Child support agreements

Child support payments

Family Tax Benefit and child support

Adult child maintenance for over-18s

Proving who the other parent is

Disclaimer: The material in this print-out relates to the law as it applies in the state of Victoria. It is intended as a general guide only. Readers should not act on the basis of any material in this print-out without getting legal advice about their own particular situations. Victoria Legal Aid disclaims any liability howsoever caused to any person in respect of any action taken in reliance on the contents of the publication.

We help Victorians with their legal problems and represent those who need it most. Find legal answers, chat with us online, or call us. You can speak to us in English or ask for an interpreter. You can also find more legal information at

Reviewed 12 April 2022

In this section