The Guides to Social Policy Law is a collection of publications designed to assist decision makers administering social policy law. The information contained in this publication is intended only as a guide to relevant legislation/policy. The information is accurate as at the date listed at the bottom of the page, but may be subject to change. To discuss individual circumstances please contact Services Australia.

1.1.A.130 ATI indexation factor

Definition

The ATI (1.1.A.20) indexation factor is used to calculate a parent's (1.1.P.10) provisional income (1.1.P.130) (2.4.4.40) if there is no tax assessment for a parent for the last relevant year of income (1.1.L.10) (but a tax return for a previous year of income (1.1.Y.10)). The ATI indexation factor is calculated to 3 decimal places.

The provisional income would be calculated by multiplying the parent's ATI for a previous financial year by the ATI indexation factor.

How the ATI indexation factor (section 58AA) is calculated:

  • AWE amount for the December quarter of the last relevant year of income ÷ AWE amount for the December quarter of the tax return year.

Example: The Registrar is required to make an assessment for a new CSP (1.1.C.150) from 1 August 2024. The last relevant year of income for the new assessment is 2023–24 and a tax assessment is available for the previous year 2022–23 ($30,000). The AWE amount for:

  • 2023-24 is the 2023 amount $1,431.10
  • 2022-23 is the 2022 amount of $1,376.60.

The ATI indexation factor is $1,431.10 ÷ $1,376.60 = 1.040.

The ATI indexation factor is calculated with reference to the trend all employees AWE figure for the December quarter (November reference period) published by the ABS and is used in the calculation of assessments where required from the following 1 July.

The Australian Statistician temporarily suspended publication of the AWE trend series from May 2020. In consultation with the Australian Statistician, an alternative AWE amount has been determined for this December quarter. Calculations of the ATI indexation factor for CSPs that begin from the following 1 July use the determined amount.

Note: From 1 July 2011 to 30 June 2013, the ATI indexation factor was calculated with reference to the September quarter AWE figure (August reference period). Due to changes in the frequency of AWE publications, the December quarter (November reference period) AWE figure is used to calculate the ATI indexation factor for all CSPs commencing from 1 July 2013.

Act reference: CSA Act section 58 Determination by the Registrar of a parent's adjusted taxable income, section 58AA ATI indexation factor for determinations under section 58

Child Support (Assessment) (AWE amount) Determination 2021

Child Support (Assessment) (AWE amount) Determination 2022

Policy reference: CS Guide 2.4.4.40 Provisional income - determination of ATI

Last reviewed: