The Child Support (Assessment) Act 1989 (Cth) came into force in 1989 and replaced previous legislation, both State and Federal, in relation to child support, formerly called child maintenance. That legislation exclusively covers the children to whom it applies.

The jurisdiction of the Family Court and the Federal Circuit Court in relation to child maintenance issues is limited to:

• applications for urgent child maintenance, pursuant to s 139 of the Child Support (Assessment) 1989 Act and s 77 of the Family Law Act 1975; and

• orders in respect of “adult” children (ie over 18 years old), pursuant to s 66L of the Family Law Act 1975.

An urgent child maintenance application can only be made if an application for administrative assessment has also been made but has not yet been determined: s 139 Child Support (Assessment) Act 1989.

An order made by the court for urgent child maintenance must be expressed to come to an end on the issue of the child support assessment and at best it has only short term effect: s 139, Child Support (Assessment) Act 1989.

See Urgent child maintenance.

As a general rule, child support assessments cease to have effect when the child turns 18. The Family Court and the Federal Circuit Court have jurisdiction to make orders for children over the age of 18 years:

• to enable the child to complete his or her education (see Adult child maintenance — Education); or

• because of a mental or physical disability of the child (see Adult child maintenance — Disability).

The court can make child maintenance orders that begin when the child is under 18 years but continue after the child obtains 18 years. Alternatively, the maintenance order can begin after the child has obtained 18 years: ss 66L(1), (2) of the Family Law Act 1975.

The making of such an order is not mandatory, but at the discretion of the judicial officer and guided by Pt VII Div 7 Subdiv D of the Family Law Act 1975. Only the court, and not the Child Support Agency, can make child maintenance orders for children over the age of 18 years.

The provisions of Pt VII Div 7 Subdiv D of the Family Law Act 1975 (applying for and making child maintenance orders) which govern child maintenance orders in respect of children under the age of 18 years, will still be relevant to an exercise of this power and forming an assessment as to what orders should be made: Smith v St James; Smith v Wickstein . Much of the case law suggests that a maintenance order will only be granted where it is “necessary”.

See Adult child maintenance.