1. The issues that arise in this application are:
   • Should the existing care percentage determination be revoked and if so, from what date should the revocation take effect?
   • Should an interim determination of the care apply?
   • What is the relevant care period, in which to assess the care arrangements of the children, and what are the percentages of care for the children during the care period?
   • Should or can an interim care determination be made?

1. The jurisdiction and power to conduct this review is due to the combined effect of sections 80A, 87 and item 2 of the table in section 89 of the Child Support (Registration and Collection) Act 1988 as read with sections 131C, 131D and 131E of the Administrative Review Tribunal Act 2024.
2. The Child Support (Assessment) Act 1989 (the Assessment Act) as it relates to the percentage of care used in a child support assessment, contains the relevant provisions regarding the revocation of an existing care percentage determination for a child and the making of a new care determination. I have had regard to the Child Support Guide (the Guide) where relevant, so long as what it contains is lawful. However, I am not bound to follow it.[2]
3. If an assessment of the percentage of care of a child has been made, that percentage of care continues to be used until the Registrar is informed, or becomes aware, that an anticipated pattern of care did not eventuate, or has subsequently changed.
4. If notified of a change in the actual or anticipated pattern of care of a child, the Registrar must consider whether such a change occurred. If the Registrar is satisfied that it did, then the percentages of care used in the assessment may, or in some cases must, be revoked (sections 54F, 54G and 54H of the Assessment Act) and another assessment must be made using newly determined percentages of the actual care the parties provided or are likely to provide to the child in a newly determined care period.[3]
5. In revoking an existing care determination, the relevant provisions are sections 54F, 54G and 54H in Subdivision C of Division 4 of Part 5 of the Assessment Act. Section 54H of the Assessment Act can only apply if sections 54F and 54G do not apply. Section 54F only applies if section 54G of the Assessment Act does not apply.
6. In considering changes, the Registrar usually considers a care period of 12 months from when the actual pattern of care of a child began or changed.[4] If the assessment is made before the end of the care period, the Registrar must make a partially forward-looking judgment as to the care of the child a party to the assessment is likely to provide over the period. In doing so, the Registrar considers whether a party to the assessment has had, or is likely to have, a 'pattern of care' for the child during the care period. The pattern of care informs the assessment of the 'percentage of care' to be used.
7. The pattern and percentage of care will commonly be determined by reference to the number of nights each child spends in the care of each party to the assessment.[5] This is usually the best method of determining the care of each party to the assessment. However, there may be occasions where the nights in care do not accurately reflect care arrangements for the child and other factors will need to be considered.[6]
8. Once it has been determined that the pattern of care for a child has changed and that the existing care determination should be revoked, a new care percentage determination will be made based on the actual pattern of care that a person has had or is likely to have.
9. Even where a care change applies based on the actual care occurring, the Registrar can make an interim determination in certain circumstances, which continues the percentages of care recorded in the child support case in line with court-ordered care. Section 51 of the Assessment Act provides for such interim determinations. As determined by Logan J in the Federal Court decision of Child Support Registrar v CMU23 [2024] FCA 109 (CMU23), paragraph 53(1)(c) of the Assessment Act (as in force prior to 29 March 2024) provided that an interim determination cannot apply if a previous care determination has been revoked under sections 54F or 54H of the Assessment Act.
10. The Social Services Legislation Amendment (Child Support and Family Assistance Technical Amendments) Act 2024 (the Amending Act) repealed paragraph 53(1)(c) in relation to changes of care that occurred from the date of commencement of the Amending Act, that is, from 29 March 2024.
11. As the change in care in this application occurred before 29 March 2024, I am bound by the Court's reasoning in CMU23. I must also apply the legislation in force prior to 29 March 2024, specifically that paragraph 53(1)(c) of the Act prevents an interim determination being made if pre-existing percentages of care are revoked pursuant to sections 54F or 54H of the Act. However, if I find that revocation must be made pursuant to section 54G of the Act, then paragraph 53(1)(c) of the Assessment Act does not prevent an interim care determination being made in relation to the change in care of the child, if the necessary requirements of section 51 of the Act are satisfied.
12. In making this decision, I have considered all the evidence before me, to determine the relevant facts and what care percentages should be applied to Mr HKCF and Ms WYYS in this application.

1. The evidence of both Ms WYYS and Mr HKCF was uncontroversial in relation to the care of the child. Both the mother and father stated that the care of the child before 16 April 2023 was that Ms WYYS had 62% care of the child and Mr HKCF had 38% care of the child. This care was based on court orders made in 2016, which were then amended in 2019.
2. On 16 April 2023, Ms WYYS confirmed that Mr HKCF's care of the child increased to 100% and that the care according to the court orders was not occurring. Ms WYYS also confirmed that the child was being withheld from her care and Mr HKCF agreed that from 16 April 2023, the care of the child was being withheld on advice from child protection who were involved with this matter.
3. I note the documentary evidence before me which shows that Ms WYYS sought advice in relation to the care not occurring in accordance with the court orders and that she subsequently filed a contravention application in the Federal Circuit and Family Court. I note that on 15 September 2023, the contravention application was dismissed by the court.
4. As there is no dispute as to the circumstances in this case, I am satisfied that Mr HKCF had 100% care of the child from 16 April 2023 and that Ms WYYS did not have any care of the child from 16 April 2023. I am also satisfied that Mr HKCF withheld the care, based on advice from child protection, and that Ms WYYS made an application to the Federal Circuit and Family Court for contravention of the court order which was ultimately dismissed on 15 September 2023.
5. I am satisfied that the appropriate care period to consider is the period from 16 April 2023, as this is when the care for the child changed. I am satisfied that the percentages of care should be assessed as 0% to Ms WYYS and 100% to Mr HKCF from 16 April 2023. Accordingly, I have considered under which section of Subdivision of Division 4 of Part 5 of the Assessment Act should apply in the revocation of the care determinations of Ms WYYS and Mr HKCF.
6. I am satisfied that Ms WYYS was to have at least 62% care of the child and Mr HKCF was to have at least 38% care of the child according to the care determination in place from 16 March 2023. Accordingly, I find that paragraphs 54G(1)(a) and (c) of the Assessment Act are met. I am also satisfied that Ms WYYS was not having any care of the child from 16 April 2023. As Ms WYYS was not having any care of the child and Mr HKCF was not making the child available to Ms WYYS, I find that paragraph 54G(1)(b) of the Assessment Act is not met. Accordingly, as paragraph 54G(1)(b) is not met, section 54G does not apply and the existing percentages of care are not able to be revoked pursuant to this section.
7. Section 54F allows for the revocation of an existing care determination, when section 54G does not apply. Section 54F states that if the Registrar is notified, or becomes aware, that the actual care that is taking place does not correspond with the existing percentages of care recorded, and the change would alter the cost percentage used for a parent in the administrative assessment, then the existing care determination can be revoked. The table in section 55C of the Assessment Act contains the relevant cost percentages that apply to the percentages of care of the parent or non-parent carer.
8. In this matter Mr HKCF notified on 18 April 2023 that the care which was actually taking place did not correspond with the existing care percentages for Ms WYYS and himself. As stated above, I am satisfied that Ms WYYS was to have 67% care of the child and Mr HKCF was to have 33% care of the child under the existing care determination and that from 16 April 2023 Mr HKCF was having 100% care of the child and Ms WYYS was having 0% care of the child.
9. The actual care Mr HKCF and Ms WYYS had did not correspond with the existing care percentages of care recorded, and the change to 100% care of the child to Mr HKCF and 0% care to Ms WYYS would alter the cost percentage used in the administrative assessment. I am satisfied that section 54F applies and the requirements under subsections 54F(1) and (2) of the Assessment Act have been met. The existing care percentages of 67% to Ms WYYS and 33% to Mr HKCF must be revoked in accordance with section 54F and new care percentage determinations must be made under section 49 of the Assessment Act, as Ms WYYS had no pattern of care from 16 April 2023.
10. I have determined that the care should be changed to reflect that the child was in Mr HKCF's care for 100% of the time and in Ms WYYS's care 0% of the time. Accordingly, the previous determination of care made on 16 March 2023 is revoked. Paragraph 54F(3)(a) of the Assessment Act provides that as the change in care was notified within 28 days after the event, the care is revoked from the day before the change of care day. This means that the care is revoked from 15 April 2023 for Ms WYYS and Mr HKCF.

Can percentage of care determinations different to the actual care occurring from 16 April 2023 be recorded for child support purposes?

1. As stated above, when actual care changes an interim determination can be made in certain circumstances. This continues percentages of care recorded in the child support case in line with court-ordered care for an interim period. Section 51 of the Assessment Act provides for such interim determinations.
2. The Amending Act repealed paragraph 53(1)(c) in relation to changes of care that occurred from the date of commencement, that is, from 29 March 2024. However, paragraph 53(1)(c) as in force prior to 29 March 2024 applies to the 16 April 2023 change of care of the child in this matter. As the change in care in question occurred before 29 March 2024, I am bound by the Court's reasoning in CMU23 and must apply the legislation in force prior to 29 March 2024, specifically paragraph 53(1)(c) of the Act, such that an interim determination cannot be made if pre-existing percentages of care are revoked pursuant to sections 54F or 54H of the Act.
3. Accordingly, an interim determination cannot be made in this matter as the care has been revoked pursuant to section 54F of the Assessment Act and therefore the new care determination must be based on the actual care which was occurring. Accordingly, I affirm the decision under review.
4. At hearing, Ms WYYS raised issues regarding an overpayment of child support. This application could not consider this issue. Ms WYYS may wish to seek further legal advice in relation to this matter and is also encouraged to raise these matters with Services Australia as the Agency responsible for administrating the child support.

1. The Tribunal affirms the decision under review.

[1] Administrative Review Tribunal (Consequential and Transitional Provisions No.1) Act 2024.

[2] Re Drake and Minister for Immigration and Ethnic Affairs (No 2) (1979) 2 ALD 634; G v Minister for Immigration and Border Protection [2018] FCA 1229.

[3] Subsection 49(2) and paragraph 50(1)(b) of the Assessment Act.

[4] subparagraph 50(1)(b)(ii) of the Act and section 2.2.1 of the Guide.

[5] Section 54A of the Assessment Act and section 2.2.1 of the Guide.

[6] Polec & Staker & Anor (SSAT Appeal) [2011] FMCAfam 959.