Child support explained
for fathers

How child support is calculated

Child support in Australia is administered by Services Australia (formerly the Child Support Agency) using a formula set out in the Child Support (Assessment) Act 1989. The formula takes into account:

• Both parents' incomes — specifically their adjusted taxable income for the most recently assessed tax year
• A self-support amount — a portion of each parent's income that is reserved for their own living costs (currently indexed)
• Each parent's percentage of care — how many nights per year the child spends with each parent
• The costs of children — a formula-based figure that varies with the number of children and the combined income of both parents

The result is an annual amount that the paying parent transfers to the receiving parent. Payments can be made directly between parents (private collect) or through Services Australia (agency collect).

One important point: child support is based on income, not on what the other parent says you earn. If you have had a significant drop in income — through job loss, reduced hours, or a change in circumstances — you can apply for a reassessment. Do not continue paying based on an outdated income figure if your circumstances have materially changed.

How shared care affects payments

The percentage of nights your children spend with you directly affects your child support liability. Services Australia categorises care as follows:

• Below 14% of nights (fewer than 52 nights per year): you are not credited with any direct cost of care — you pay the full assessed amount
• 14–34% of nights (52–127 nights): you receive a partial credit for the costs you incur directly
• 35–47% of nights (128–175 nights): significant credit applied — assessment reduces substantially
• 48–52% of nights (176–189 nights — roughly equal care): the higher-earning parent typically pays the difference, often a reduced amount

This means that increasing your parenting time has a direct financial effect. Fathers who are seeking more time with their children for the right reasons — because they want to be involved in their children's lives — often find that the financial outcome also improves. Do not let concerns about child support drive decisions about parenting time, but do understand the relationship.

Changing an assessment

If you believe your child support assessment is not fair, there are formal mechanisms to challenge it.

Objection to Services Australia: If you disagree with an assessment, you can lodge an objection within 28 days. Services Australia reviews the decision internally. This process is free.

Change of Assessment application: If you have grounds to argue that the formula result is unjust given your specific circumstances, you can apply for a Change of Assessment. There are ten specific grounds under the legislation, including:

• The other parent's income or earning capacity is significantly higher than assessed
• The costs of caring for a child are unusually high (e.g., special needs)
• You have significant costs associated with spending time with the children
• A significant change in your financial circumstances has occurred

Appeal to the Administrative Review Tribunal: If you are unhappy with the outcome of a Change of Assessment decision, you can appeal to the ART (formerly AAT). Legal representation at this level is strongly advisable.

Private agreements

Parents can choose to opt out of the Services Australia formula entirely and make their own child support agreement. There are two types:

Limited agreements require one parent to have a current assessment and can only be entered into if the agreed amount is at least equal to the assessed amount. They can be terminated by either parent after 3 years.

Binding Child Support Agreements are more flexible — they can be for any amount, do not require a current assessment, and can cover specific items like school fees or medical expenses. Each party must receive independent legal advice before signing. They are legally binding and can only be set aside in limited circumstances.

A binding agreement can be a good outcome when both parents are genuinely in agreement and want certainty. It can also be used strategically — for example, where the formula produces a figure that is unfair given the particular family's circumstances. Get advice before signing anything.

Enforcement issues

If a parent is not paying child support, Services Australia has significant enforcement powers including garnishing wages, intercepting tax refunds, and withholding departure from Australia. If the other parent is not paying and you are the receiving parent, Services Australia is your first point of contact.

The more common enforcement issue for fathers is this: paying child support faithfully, but the other parent is not complying with parenting orders. These are legally separate matters. Child support and parenting time do not cancel each other out — you cannot withhold child support because your ex is withholding the children, and you cannot withhold children because the other parent isn't paying. Both obligations run independently.

Common misconceptions

"If I pay child support, she controls how it's spent."
Child support is paid to meet the costs of the child generally — it is not tagged to specific expenditure. The receiving parent determines how it is used within the household. You cannot direct how it is spent, but you can seek a Change of Assessment if you believe costs are genuinely not being applied to the children's benefit.

"If I lose my job I can stop paying."
No. Your obligation continues even if your income drops. You must notify Services Australia of the change in income promptly, and they will reassess. Continuing to pay the old amount — or stopping entirely — creates a debt that can be difficult to resolve. Act quickly and formally.

"Extra things I buy for the kids reduce my child support."
Not automatically. Direct costs — school uniforms, sports registration fees you pay directly — may be taken into account in a Change of Assessment, but ad hoc gifts and purchases are generally not credited against the formula amount.

"Child support ends when the child turns 18."
Generally yes — the standard assessment ends at 18. But if a child is still in secondary school at 18, child support can extend until they complete their schooling or turn 19, whichever comes first.