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2.3.2 When do child support periods start?

Context

The Registrar must make new assessments at particular times. A new assessment starts a new child support period. The date of the start of the child support period determines which financial year of income the Registrar uses to make the assessment.

Amending an assessment, for example because a parent has lodged an estimate of their income, does not start a new child support period.

Act reference

CSA Act section 7A, section 31, section 34A, section 34B, section 34C, section 40B, section 93, section 5, section 43

On this page

Last relevant year of income

The Registrar makes child support assessments using the last relevant year of income for the child support period to which the assessment will apply (section 43). The last relevant year of income for a child support period is the last year of income that ended before the start of the period (section 5).

Example: A child support period starts in December 2022. The last relevant year of income would be 2021-22 as it ended in June 2022.

When the Registrar is required to start a new child support period

The Registrar must periodically make new assessments, which apply to new child support periods, in the following circumstances:

Accepting an application for assessment

The Registrar must make an assessment as quickly as practicable after accepting a new application for an administrative assessment of child support (section 31(1)). The child support period for this assessment starts on the day that the application was received (section 7A(2)(a)).

Note: A new child support period will not be initiated by:

  • the acceptance of an application from a non-parent carer to receive child support under an existing child support assessment (that is, there is already an assessment between the parents for the child and there has been no terminating event) (section 40B(3)), and
  • the acceptance of an application to add a new child to an existing case.

Instead, the Registrar will amend the existing assessment to take account of these events.

Accepting a child support agreement that starts a new case

The Registrar must make an assessment as quickly as practicable after accepting a child support agreement that starts a new case (section 93(2)). An assessment and child support period will start on the day that the liability to pay child support starts, that is from the day on which the application for acceptance of the agreement was made to the Registrar (sections 7A(2)(b) and 93(1)(g)).

Accepting a child support agreement on an existing case where the agreement affects the rate of child support payable

The Registrar must make a new assessment immediately after accepting a child support agreement in an existing case if the agreement affects the rate of child support payable (section 34B(1)). The new assessment applies to a new child support period that starts on the day that the agreement alters the rate of child support payable (section 7A(2)(c)). For more details of the date of effect of a child support agreement where child support is already payable, see 2.7.4.

The Registrar makes an assessment when the ATO issues an income tax assessment for one of the parents

The Registrar must make a new assessment when an income tax assessment issues for either parent for the latest financial year that ended during the existing child support period (section 34A). The Registrar must do this as soon as it is practicable after the ATO issues the assessment (section 34A(2)).

Generally, it is practicable to make an assessment in the month that the tax assessment issues if it issues on or before the 15th of the month. If the tax assessment issues after the 15th of the month the Registrar will generally make the assessment in the following month and commence that assessment and a new child support period on the first of the month after that.

The new assessment applies to a new child support period that starts on the first day of the month after the month in which the assessment was made (sections 34A(2) and 7A(2)(d)).

When the Registrar is not required to make a new child support assessment

The Registrar may not be required to make a new child support assessment and start a new child support period when the ATO issues an income tax assessment (for the latest year of income that ended during the existing child support period) in the following circumstances:

Income tax assessment could not affect the rate of child support

The first exception is where the tax assessment could not affect the rate of child support payable, for example because the parent's income continues to be below the self-support amount (section 34A(3)(a)).

Example: Casey has a care percentage of 100% for 2 children. The assessment is based on the last relevant income for Casey of $18,140 and for the other parent, George, of $36,314. On 14 July 2021, Casey's 2020-21 tax return issues and the ATI is $17,135.

As Casey's income continues to be below the self-support amount and will not affect the rate of child support payable, the Registrar is not required to make a new assessment and start a new child support period.

Casey's 2020-21 income will be used in the new child support period which will commence after the end of the 15-month period or after George lodges a tax return with an ATI that affects the rate of child support payable (whichever is earlier).

Example: Sarah has a care percentage of 100% for 2 children. The assessment is based on the last relevant income for Sarah of $37,400 and the other parent, Chris, of $36,314. On 10 July 2021, Sarah's 2020-21 tax return issues and the ATI is $17,135.

As Sarah's income is lower than the income that is currently used in the assessment, and this will affect the rate of child support payable, the Registrar is required to make a new assessment and start a new child support period from 1 August 2021.

A new child support period has already started during the current financial year

The second exception is where a new child support period has already started during the income year. For example, a new child support period has started because the Registrar has accepted a new agreement, or the other parent's income tax assessment for that year has already started a new child support period.

Example: Peta and Steven's child support assessment commenced on 1 April 2021 with an annual rate of $2,146 based on the 2019-20 taxable incomes.

Peta lodges her tax return and, on 28 September 2021, her 2020-21 tax assessment becomes available. A new child support period starts on 1 November 2021 using Peta's 2020-21 ATI of $47,236 and a provisional ATI of $32,231, determined by the Registrar, for Steven.

Steven's 2020-21 tax return issues on 3 December 2021 and his ATI is $34,635. As a new child support period has already started during the income year (to use Peta's ATI of $47,236), the Registrar will not be required to make a new assessment and start a new child support period as a result of Steven's tax return issuing.

When the assessment was made, an income determined by the Registrar will have been used for the parent (or parents) whose income tax assessment had not yet issued. When the parent's income tax assessment subsequently issues for the same year, it does not trigger a new child support period. The income tax assessment is not for a financial year that ended during the current child support period. The Registrar will amend the existing assessment by replacing the Registrar determined income. The assessment continues and applies to the same child support period.

Similarly, if an amended tax assessment issues for either parent, it will not start a new child support period, but the Registrar may amend the existing assessment to take into account the amended tax assessment.

Assessment based on a change of assessment decision, court order or agreement

The third exception is where a change of assessment decision, court order or child support agreement is in place that does not use the parent's taxable income to work out the rate of child support (section 34A(3)(b)).

If the child support agreement, change of assessment decision or court order ceases at some time during the existing child support period, the Registrar is required to make a new assessment when the income tax assessment will affect the rate of child support. The Registrar makes a new assessment during the last calendar month in which the child support agreement, change of assessment decision, or court order has effect. This new assessment applies to a period that starts on the first day of the month following the making of the assessment (section 34A(2)).

Most child support agreements, court orders and change of assessment decisions will end on the last day of a month. If not, the assessment will revert to the formula using the last relevant year of income for the current child support period until the last day of the month. The new assessment using the later year of income will apply to a period that commences on the first day of the month after which the Registrar makes that assessment (section 34A(2)).

Current child support period ending in the same month

The fourth exception is where the existing child support period will finish before the end of the month in which the income tax assessment issues. In these cases, a new child support period starts on the day after the end of the current child support period, rather than the first day of the following month (section 34A(3)(c)).

Can the Registrar start a child support period retrospectively when a new tax figure is available?

If the Registrar missed making a new assessment when a parent's income tax assessment issued, a retrospective assessment cannot be made (section 34A(2)). The Registrar will make a new assessment at the earliest appropriate time, noting the general rule for practicability outlined above. If a new financial year has started before the Registrar discovers the error, and the last relevant year of income has therefore changed, the Registrar will not be able to make a new assessment based on that income tax assessment. However, the Registrar can amend the existing child support assessment using financial information from the income tax assessment if the information is more accurate for the purposes of the assessment.

Income tax assessments that issue in June for the previous financial year

When the ATO issues an income tax assessment that requires the Registrar to make a new assessment, a new child support period starts. The new income tax assessment will relate to the parent's taxable income for the last relevant year of income in relation to the new child support period. The exception is where the Registrar makes a new child support assessment in June to apply to a child support period that starts on 1 July (for example, when ATO issues an income tax assessment for 2020-21 in June 2022). The last relevant year of income for that new child support period will be the financial year after the year of the income tax assessment that is, 2021-22.

For these cases, the Registrar will make a new child support assessment based upon a provisional income amount for the last relevant year of income for both parents (2.4.4.40). When the ATO issues each parent's income tax assessment for the last relevant year of income, the Registrar will amend the child support assessment from the start of the child support period (replacing the provisional income with the actual income in accordance with the date of effect rules outlined in 2.4.4.60).

Example: A child support period commenced on 1 June 2022 involving parents Elisabeth and Maddi. The last relevant year of income for the child support period is 2020-21. On 3 June 2023, Maddi lodges their tax return for the 2021-22 income year. Elisabeth has not yet lodged their tax return for the 2021-22 income year. A new child support period will commence from 1 July 2024. The last relevant year of income for the child support period commencing on 1 July 2024 is 2022-23, not 2021-22. A provisional income for 2022-23 will be used in the child support assessment for both Elisabeth and Maddi until their respective ATO assessments are available.

After the end of a child support period

The Registrar must make an assessment before the start of a new child support period if an assessment has not already been made for one of the reasons listed above. If the Registrar has not made a new assessment before the start of a new child support period this must be done as soon as practicable after it starts (section 34C). The child support period for this kind of assessment will start on the first day after the day the earlier child support period ended (section 7A(2)(d)).

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