Important aspects of how child support is collected can be improved, the auditor-general has found, handing down a report containing a range of recommendations for federal authorities.
The national audit office has investigated just how effective child support collection arrangements are between the Department of Human Services and Australian Taxation Office.
The agencies work to ensure parents without primary care of their children make financial contributions to their upbringing by assessing incomes, collecting child support debts and promoting timely tax returns.
The ATO also intercepts tax refunds of parents owing child support, exchanging income information with DHS.
Some $3.5 billion in child support payments were transferred during 2015/16, supporting about 1.2 million kids.
The auditor-general has recommended the agencies do more to manage shared risks and better target customers for compliance programs based on relevant risk factors.
He also recommended DHS investigate the extent to which income information provided by the tax office is applied when assessing child support payments.
The report found DHS and the ATO did not explicitly or routinely test the accuracy of customers' reported incomes, amounts intercepted from tax refunds or customers' exclusion from enforcement programs.
The agencies were told to identify and implement "assurance mechanisms" in enforcing lodgements, intercepting tax refunds and exchanging information to ensure accurate and timely child support collection.
The auditor-general said DHS and the ATO should improve performance measures to demonstrate the effectiveness of child support collection.
The human services department and tax office agreed with all of the recommendations.