What Counts as Income for Child Support in Australia

Beyond the Payslip: How Income Is Really Calculated

One of the most misunderstood aspects of child support in Australia is how income is determined. Many parents assume that child support is based on their salary or take-home pay. In reality, Services Australia uses a broader measure called Adjusted Taxable Income (ATI) that captures income from multiple sources — and adds back amounts that some parents try to shelter from the assessment.

Understanding how ATI works is essential whether you are the paying or receiving parent, because getting the income figure right is often the single biggest factor in determining the child support amount.

What Is Adjusted Taxable Income?

ATI starts with your taxable income as reported to the Australian Taxation Office (ATO), then adds back several categories of income or benefits that reduce taxable income but still represent economic capacity. The formula is:

ATI = Taxable Income + Reportable Fringe Benefits + Target Foreign Income + Net Investment Losses + Tax-Free Pensions or Benefits + Reportable Superannuation Contributions

Component Breakdown

Self-Employment and Business Income

For parents who operate through a business — whether as a sole trader, through a partnership, company, or trust — determining income for child support purposes is more complex. Services Australia looks beyond the tax return to assess the parent's true economic benefit from the business.

Key areas of scrutiny include:

• Personal expenses through the business: If the business pays for a parent's car, phone, travel, meals, or other personal costs, these may be added back as income
• Excessive depreciation: Claiming accelerated depreciation on business assets reduces taxable income but does not reduce the parent's actual spending power
• Income retained in entities: If a parent controls a trust or company that retains profits rather than distributing them, Services Australia may "look through" the entity to assess the parent's real capacity
• Related-party transactions: Payments to a new partner, family member, or related entity that appear to be above market rates may be scrutinised

Personal Services Income (PSI) Rules

The Personal Services Income rules are particularly relevant to parents who earn income through a company or trust where the income is primarily generated by their personal skills and efforts. Under the PSI rules, if the income would not have been earned without the personal efforts of the individual, it may be attributed directly to them regardless of which entity received the payment.

This is common among contractors, consultants, medical practitioners, tradespeople, and other professionals who operate through company structures. The effect is that income distributed to other people (such as a new spouse) or retained in the entity can be attributed back to the parent for child support purposes.

Salary Sacrifice and Superannuation

Salary sacrifice arrangements are sometimes used by parents in an attempt to reduce their assessable income. However, the child support legislation is designed to capture most forms of salary sacrifice:

• Salary sacrifice to super: Reportable superannuation contributions (amounts salary-sacrificed into super above the employer's compulsory contribution) are added back to ATI
• Salary sacrifice to other benefits: Novated leases, additional leave, and other fringe benefits are captured through the reportable fringe benefits amount on the payment summary
• Packaged employment: Total remuneration packages that include non-cash components are generally captured through the combination of taxable income and reportable fringe benefits

In short, salary sacrifice generally does not reduce child support. The system is designed to assess total economic capacity, not just cash wages.

When Income Does Not Reflect Capacity

In some cases, a parent's reported income genuinely does not reflect their capacity to contribute to their child's support. Services Australia has several mechanisms to address this:

Income Estimates

If a parent's income has dropped significantly since the last tax return (due to job loss, reduced hours, or business downturn), they can lodge an income estimate with Services Australia. The estimate will be used for the current assessment period, but if the actual income turns out to be higher than estimated, the difference may be recovered.

Capacity to Earn

If Services Australia believes a parent is deliberately underemployed or unemployed to reduce their child support obligation, it can determine a "capacity to earn" — attributing a higher income based on the parent's qualifications, experience, and local job market conditions.

Change of Assessment (Reason 8)

Either parent can apply for a change of assessment if they believe the standard formula does not reflect the true financial position. Common grounds include income diversion through entities, undisclosed income or assets, and financial resources not captured by the ATI definition.

Practical Considerations

Getting the income figure right is often where child support matters succeed or fail. A few practical points to keep in mind:

1. Lodge tax returns on time. Services Australia uses the most recent tax return to calculate income. Delayed lodgement can result in provisional income being used, which may be higher or lower than the actual figure.
2. Keep accurate business records. If you are self-employed, clear financial records make it easier to demonstrate your true income — and harder for the other parent to argue that your income is being understated.
3. Understand what gets added back. Many parents are surprised to learn that negative gearing losses, fringe benefits, and super contributions are included in ATI. Understanding your full ATI before it is assessed helps avoid surprises.
4. Seek specialist advice for complex income. If your income involves trusts, companies, overseas earnings, or PSI, the interaction between tax law and child support law can be intricate. Getting it right — or challenging an incorrect assessment — often requires specialist knowledge.