Names used in all published decisions are pseudonyms. Any references appearing in square brackets indicate that information has been omitted from this decision and replaced with generic information pursuant to subsection 16(2AB) of the Child Support (Registration and Collection) Act 1988.

1. Mrs Hogan and Mr Brannagan are the parents of [Child A] (born [in] January 1999) and [Child B] (born [in] July 2002). A case was registered with Services Australia - Child Support (Child Support) for the assessment of child support on 14 July 2009. From the commencement of the child support period 1 December 2014 to 29 February 2016, Mr Brannagan was assessed to pay Mrs Hogan $713.83 per month in child support. This rate was based on the provisional income of $56,667 for Mr Brannagan and Mrs Hogan's 2013-14 adjusted taxable income of $64,275. The next child support period commenced on 1 September 2015, following Mrs Hogan's lodgement of her income tax return. From this date Mr Brannagan was assessed to pay Mrs Hogan $794.83 per month in child support. This rate was based on the provisional income of $57,322 for Mr Brannagan and Mrs Hogan's 2014-15 adjusted taxable income of $65,234.
2. In 2017 Child Support received updated income details for Mr Brannagan, following the lodgement of his income tax returns for several years. The parties were notified by letters dated 5 April 2017 that the rate of child support payable by Mr Brannagan had been reassessed for the period 1 December 2012 to 30 November 2017 to take into account the new income amounts provided. The new rate payable by Mr Brannagan in this period took into account his assessed adjusted taxable income for the 2011-12, the 2012-13 and the 2015-16 years and retained provisional income amounts for the 2013-14 and 2014-15 years. The child support assessment ended on 11 November 2020, as the youngest child of the assessment had turned 18 and would be ceasing secondary studies.
3. On 22 February 2024, Child Support identified that there had been an error in the child support assessment for the period 1 December 2014 to 31 August 2016 and this had resulted in Mr Brannagan's assessed income being higher than it should have been in that period. As a result, Mr Brannagan's child support liability had been incorrectly increased by a total of $7,033.11. The parties were notified by letters dated 19 April 2014 that Mrs Hogan had been overpaid $7,033.11 in child support and this amount needed to be repaid by her.
4. On 1 May 2024 Mrs Hogan lodged an objection to the decision of 19 April 2024. On 23 May 2025, an objections officer of Child Support disallowed the objection, which had the effect of affirming the original decision.
5. By application received on 11 June 2025, Mrs Hogan asked this Tribunal to review the decision of the objections officer. On 1 September 2025, the Tribunal conducted a hearing at which Mrs Hogan and Mr Brannagan gave evidence by MS Teams audio. The Tribunal had before it the relevant documents from Child Support, which had been copied to the parties.

1. The legislative provisions relevant to this decision are contained in the Child Support (Assessment) Act 1989 (the Act). The Act sets out the statutory formula for the calculation of child support, which takes into account each parent's adjusted taxable income and the level of care they provide for each child of the assessment.
2. Generally the adjusted taxable income of a parent is the amount assessed by the Australian Taxation Office for the last relevant year. Where a person has not lodged a tax return for that year, section 58 of the Act provides that Child Support may work out "a reasonable approximation of the parent's adjusted taxable income for that year" to be used in the assessment. This amount is known as the provisional income. Section 58A then sets out how the rate is reassessed when a parent subsequently lodges their income tax return for the relevant year. If the income tax return has not been lodged by the date required under the tax law, then their adjusted taxable income for the relevant period is to be retrospectively reassessed as the higher of their actual adjusted taxable income for that year (as assessed) or the provisional income used at the time.
3. In Mr Brannagan's case, it is common ground, and the Tribunal finds, that his actual adjusted taxable income for the 2013-14 year as assessed by the Australian Taxation Office, was $80,722 and for the 2014-15 year, $78,051. He did not lodge his income tax returns for those years until 2017, which was after the due date required by the Australian Taxation Office. The income that had been used in the assessment from 1 December 2014 was a provisional income of $56,667 and from 1 September 2015, a provisional income of $57,322. Once Mr Brannagan's actual adjusted taxable income was known, these amounts ($80,722 and $78,051 respectively) should have replaced the provisional incomes that had been used in the assessment. Due, however, to a Child Support computer error, when the child support liability was reassessed on 5 April 2017 new provisional income amounts of $95,614 and $96,855 were used as Mr Brannagan's income for the relevant period, rather than the actual assessed amounts. This incorrectly inflated the amount he was assessed to pay Mrs Hogan by $7,033.11 over the period. Mr Brannagan had paid the full liability by the time that the error was discovered in 2024.
4. This brings us to the matter at issue. Section 75 of the Act provides that Child Support, and the Tribunal standing in the shoes of the Child Support Registrar, "may, at any time, amend any administrative assessment by making such alterations and additions as the Registrar considers necessary to give effect to this Act or the Registration and Collection Act" (the Child Support (Registration and Collection) Act 1988). Use of the term "may" indicates that there is a discretion involved: it is not mandatory for the error to be corrected.
5. Mrs Hogan submits that the error should not be corrected and she should not be liable to repay Mr Brannagan the amount assessed. Her reasons for this are set out in her objection to Child Support lodged on 1 May 2024. In summary, Mrs Hogan states that the amounts paid by Mr Brannagan were used for the benefit of the children when they were still children. They are now adults with children of their own. The overpayment was not due to any error she had made and she has had no control over this issue. Mrs Hogan told the Tribunal at the hearing that recovery of the amount overpaid many years after the termination of the child support assessment is unfair and is affecting her both financially and emotionally.
6. Mr Brannagan told the Tribunal that he had been completely unaware of the error until Child Support called him last year. They asked him whether he wanted to gift the amount overpaid to Mrs Hogan or whether he wanted it back. He wants it back.
7. The Tribunal acknowledges the concerns raised by Mrs Hogan and accepts the evidence of both parties as accurate. In determining whether to exercise the discretion contained in section 75 to correct the error that has occurred in this case, the Tribunal has had regard to Australian government policy as set out in the Child Support Guide (the Guide). The Guide contains governmental guidelines and policy as to how the legislation is to be applied. The Tribunal acknowledges that, whilst it may be guided by policy, it is not bound to follow it: Re Drake and Minister for Immigration and Ethnic Affairs (No 2) (1979) 2 ALD 634. In the more recent case of G v MIBP [2018] FCA 1229, the Federal Court observed that it is clear from earlier authorities, that in the absence of any statutory indication to the contrary, any lawful executive policy enacted to guide the exercise of a statutory power is a relevant factor for the Tribunal to take into account in performing its review task. A lawful approach allows the adoption of appropriate policy as a guide but not so as to control the making of the decision and the Tribunal adopts that approach.
8. The relevant part of the Guide in this matter is set out in Chapter 11.3 as follows:

When deciding whether to correct (or not) an error, the Registrar will consider the objects of the Acts and the legislative requirements of the decision affected by the error. The Registrar can also consider circumstances including, but not limited to, the wishes of the affected parents, the integrity of the child support (1.1.C.60) scheme, and the impact on each parent of correcting or not correcting the error.

Error correction decisions are made in the context of the particular circumstances of each case. The circumstances in one case may mean it is appropriate to correct an error in that case, but it may not be appropriate to correct a similar error in another case.

The Registrar may be more likely to decide to correct an error where:

• it is an obvious error of fact, and can be fixed simply
• it impacts the current assessment or liability
• both parents want the error corrected
• one parent wants the error corrected and the other parent does not want it corrected
• the Registrar caused the error or substantially contributed to it
• one parent wants the error corrected and the other parent cannot be contacted.

The Registrar may be less likely to decide to correct an error where:

• neither parent wants the error to be corrected
• there will be no material change to an assessment or financial impact as a result of correcting the error
• only one of the affected parents is contactable and they do not want the error corrected
• there is no utility to correcting the error, or it would be inappropriate to correct - such as when the error is the subject of merits or judicial review proceedings (whether internal or external to Services Australia).

1. In this case, the error is an obvious error of fact, the Registrar caused the error and one parent (Mr Brannagan) wants the error corrected while the other (Mrs Hogan) does not. The Tribunal accepts that the policy as set out above is in accordance with the objects of the legislation and concludes that it should be followed in the interests of consistent decision-making. As the majority of the points set out in Chapter 11.3 of the Guide support exercising the discretion to correct the error, the Tribunal determines that the decision to apply section 75 in this matter was correct.