How child support is calculated and paid

Child support is money paid by one parent to the other, or to another carer, towards the cost of raising a child after the parents separate. It is separate from spousal maintenance, which is support for a former partner, and separate from the division of property.

Child support is run by Services Australia under the Child Support (Assessment) Act 1989 (Cth). It applies in the same way to children of married and unmarried parents, and the same scheme applies in Western Australia as in the rest of the country. A parent or carer can apply for an assessment at any time after separating. There is no need to wait for a divorce.

The formula

Services Australia works out child support with a formula in eight steps. In short:

(a) each parent's child support income is worked out: their adjusted taxable income, less a self-support amount and any allowance for other dependent children;

(b) the two incomes are added to give a combined child support income, and each parent's share of it is worked out as a percentage;

(c) each parent's percentage of care is worked out from the number of nights a year the child is in their care, and converted into a cost percentage, which is the share of the child's costs that parent meets directly through care;

(d) each parent's cost percentage is taken away from their income percentage. A parent with a positive result pays child support; a parent with a negative result receives it;

(e) the costs of the child are read from the Costs of Children table, which depends on the combined income, the number of children and their ages;

(f) the paying parent's positive percentage is multiplied by the costs of the child.

The formula does not look at the parents' assets. It works from taxable income, with some additions, and from care.

The 2026 figures

These figures apply to child support periods starting in 2026. They were read from Services Australia on 27 October 2026 and change each 1 January:

(a) self-support amount: $31,046;

(b) the combined income above which the costs of children do not increase: $232,843;

(c) fixed annual rate, which can apply to a parent on a low income who is not receiving income support: $1,825 per child per year;

(d) minimum annual rate: $551 a year.

The Costs of Children table has separate rates for children aged 12 and under and for those aged 13 and over. Because the figures move every year, the safest way to estimate your own assessment is the estimator on the Services Australia website.

How care affects the amount

Care is counted in nights. A parent with fewer than 52 nights a year, under 14 per cent care, has a cost percentage of nil. Regular care of 52 to 127 nights gives a cost percentage of 24 per cent. Shared care, of 128 to 237 nights, gives a cost percentage on a sliding scale that reaches 50 per cent at equal care. Primary care, from 238 nights, gives 76 per cent, and more than 313 nights gives 100 per cent. Tell Services Australia promptly when care changes.

Agreeing a different arrangement

Parents can instead make a limited or a binding child support agreement, which takes effect once Services Australia accepts it. A separate article explains the two kinds.

How child support is paid

Once there is an assessment, an accepted agreement or a registered court order, there are two ways of collecting it.

Child Support Collect

Services Australia collects the payments from the paying parent and passes them to the receiving parent. It keeps payment records and can recover overdue amounts. It suits parents who find it hard to deal with each other about money, or where payments have not been reliable. Only the receiving parent can apply for it.

Private Collect

The parents pay each other directly, at the amount Services Australia sets, and keep their own records. Services Australia suggests it may not suit parents who are worried about their safety, whose incomes change often, or for whom money is a source of conflict.

Some parents manage their children's costs between themselves without any assessment at all. Services Australia notes this can reduce the Family Tax Benefit Part A a receiving parent gets.

Where Services Australia collects, a paying parent can sometimes have a payment made directly to the other parent, or to a third party such as a school, counted as child support. These are called non-agency payments. Where both parents agree, many kinds of payment can be credited. Where the receiving parent does not agree, only certain prescribed payments can be credited, and only up to 30 per cent of the child support, if the paying parent has less than 14 per cent care and is paying at least 70 per cent of the monthly amount on time. Talk to the other parent, and to Services Australia, before relying on one.

Child support and the property settlement

Child support often has to be settled at the same time as the property. The two interact: the court takes child support into account when dividing property and when deciding spousal maintenance. If you are working out child support, it is worth looking at the whole financial picture together.

This article is general information, not legal advice.