1. The issues that arise in this application are as follows:
   • Should the existing percentage of care determinations be revoked and if so, from what date should the revocation take effect?
   • In determining to revoke the existing percentage of care determinations, 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?
   • In revoking the existing percentage of care determinations, what new percentage of care determinations should be made?
   • if there is a change in the percentages of care attributed to the parents, from what date should the administrative assessment be amended to reflect the change?

1. Division 4 of Part 5 of the Child Support (Assessment) Act 1989 (the Assessment Act) provides the legislative basis for the making and revocation of a percentage of care determination. The percentage of care for a party to a child support assessment assists in determining the applicable cost percentage of the child or children that each parent is meeting directly through the care they provide. A parent or non-parent carer's percentage of care is calculated based on the care they provide, or are likely to provide, for the child in the relevant care period. In conducting the review, I may also have 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]
2. As has often been said in respect of merits review, I 'stand in the shoes'[3] of the original decision-maker, in that I am to determine for myself, on the material before me, the decision which can, and which I consider should, be made in the exercise of the power or powers conferred on the original decision-maker for the purpose of making the Original Decision. As section 9 of the ART Act makes clear, the Tribunal makes its decision independently. I am, however, also subject to the same constraints as the original decision-maker.[4]
3. Sections 80A and 89 of the Child Support (Registration and Collection) Act 1988 (Cth) (the Collection Act) provide that the parties to the assessment may lodge an objection to a care percentage decision made by the Registrar and can then seek Tribunal first review of the objection decision.
4. I have jurisdiction and power to conduct this second review due to the combined effect of subsection 131D(1) of the Administrative Review Tribunal Act 2024 (Cth) (the ART Act), read with sections 12, 105, and 131C(d) of the ART Act. There is no presumption that the Tribunal first review decision is correct.[5]
5. Ordinarily, once an assessment of the percentage of care of a child is made and applied by the Registrar, the 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 that it subsequently changed.
6. If notified of an alleged 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 and another determination must be made using the percentages of care corresponding with the actual care the parties provided or are likely to provide to the child in a newly determined care period.[6]
7. 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. To revoke the care under section 54G of the Assessment Act, all of the requirements under subsection 54G(1) must be satisfied for that section to apply. Specifically, subsection 54G(1) of the Assessment Act provides as follows:

(a) a responsible person (the first responsible person) for a child was to have at least regular care of the child during a care period under a determination (the first care determination) made under section 50; and

(b) the first responsible person has had no care of the child, or has had a pattern of care that is less than regular care of the child, despite another responsible person for the child making the child available to the first responsible person; and

(c) a determination of the other responsible person's percentage of care for the child has been made under section 50; and

(d) the other responsible person notifies the Registrar or the Secretary of the matter referred to in paragraph (b) of this subsection within a period that the Registrar considers is reasonable in the circumstances;

1. If section 54G of the Assessment Act does not apply, section 54F must be considered. Subsection 54F(1) of the Act states that an existing determination must be revoked if the Registrar is notified that the care taking place does not correspond with the responsible person's existing care of the child and if a new percentage of care determination were to be made the responsible person's cost percentage would change. A person's cost percentage is determined by reference to the table in section 55C of the Assessment Act.
2. The Registrar usually considers a care period of 12 months from when the actual pattern of care of a child began or changed.[7] However, the care period can be any period that is appropriate in determining the pattern of care of the child or children. 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. The term 'pattern of care' is undefined and can be interpreted according to its 'ordinary meaning'. In Parent A and Child Support Registrar and Anor [2013] AATA 562 the AAT considered the term:

The phrase 'pattern of care' is not given any special meaning for the purposes of the Assessment Act. Having regard to the text of ss 49 and 50 of that Act, and the content and purposes of Subdivision B of Division 4 of Part 5, the phrase can be interpreted according to its ordinary meaning. A pattern may be construed to mean a regular and intelligible form or sequence discernible in certain actions or situations, on which the prediction of successive or future events may be based. [8]

1. The care period is not necessarily the period for which the care determination will apply, it is simply a mechanism to enable a pattern of care to be determined. The pattern and percentage of care will commonly be determined by reference to the number of nights a child spends in the care of each party to the assessment.[9] This is usually, but not exclusively, the appropriate method of determining the care of each party to the assessment. However, there may be occasions where the nights in care does not accurately reflect care arrangements for the child and other factors will need to be considered.[10]
2. If I determine that the existing percentage of care should be revoked and make another determination of the percentage of care, I will also need to decide the date of effect of any changes to the percentage of care. Whether the application for first review was made within 28 days of the objection decision,[11] will affect the date from which any new percentage of care will apply.
3. In written submissions, the Registrar notes that if I were to set aside or vary the objection decision, I would need to determine whether to make a determination under subsection 95N(2) of the Collection Act, if the application for review to the Tribunal was made more than 28 days after the objection decision.[12] In relation to subsection 95N(2) of the Collection Act, any decision setting aside or varying the objection decision would take effect from the date of the application for review, unless there are special circumstances that prevented the lodging the application for review within time.
4. The Registrar also submits that if I were to make a determination under subsection 95N(2) of the Collection Act, it is necessary to consider whether the decision comes into effect on the date the objection was lodged or from the date of the notification of the change in the percentage of care if I found that there were special circumstances which prevented the mother from lodging the objection within time.

1. Ms CNKV relied on her application in relation to this second, including the annexures to this application. She stated, differently from what had been previously maintained with the Registrar and the Tribunal on first review, that the first review decision should be set aside and that the care percentage for Mr GJVT should be amended to 41% and a care percentage of 59% to her.
2. Ms CNKV provided a background as to why the care determination should be revoked and a new care determination made in its place. She stated that prior to the period, the child did not initially go to Mr GJVT's care but then restarted to go into his care from 15 October 2023 and did so consistently. Ms CNKV stated that she notified on 6 January 2024 of this change in care because she was waiting to see what would happen and whether it would be consistent. Once she saw it was consistent, she notified the Registrar.
3. Initially, Ms CNKV notified on 6 January 2024 that the care was 38% to Mr GJVT and 62% her, but she stated that this was incorrect and on 8 January 2024, she corrected the care change to being 41% care to Mr GJVT and 59% care to Ms CNKV.[13] Because of the number of changes, the fact that she notified of this correction was overlooked. Furthermore, she provided a marked calendar of the care of the child, which supported this care.[14]
4. It was put to Ms CNKV that this was not raised when the objection decision was made, nor was it raised on first review. Ms CNKV was asked why it was not raised in either of these reviews and she could not say why it was not discussed or why she did not refer to this amendment. In fact, Ms CNKV argued in the first review of this application that the care was as initially stated on 6 January 2024 (62% to her and 38% to Mr GJVT). She stated that she forgot about this correction due to the number of documents and applications that they had on foot, but on review of the documentation for this application before me, she picked up the error.
5. Ms CNKV confirmed that there were consent orders made on 2 September 2022.[15] These orders were made by consent and it was confirmed, as in previous reviews, that they are the current orders and they have been mainly followed by the parents, except for the occasional swapping of dates of care and the occasional missing of dates of care, due to travel and other factors.
6. Ms CNKV stated that the care of the child as specifically stated in the consent orders. Ms CNKV stated that the amended care, as submitted in this application, of the child was calculated over the period from 15 October 2023 and 14 October 2025. She stated that a two year period was a better reflection of the care of the child because of the even and odd years in the consent orders and the particular school holidays of the child's school, rather than the general school holidays for public schools, and the actual care of the child and referred to the calendar attached to the application for first review.[16]
7. Ms CNKV stated that an appropriate care period would be a two year period, commencing from 15 October 2023. Ms CNKV also stated that there are no special circumstances which prevented Mr GJVT from lodging the application within 28 days of the objection decision and therefore the decision should be made from the date of the application on first review.

1. Mr GJVT stated that the child was in his care less than what was prescribed in the consent orders for the period from May 2023 to July 2023. This decision was reviewed and he has accepted the decision in this matter and only raises this to provide historical background to the current application. As part of the consent orders, Mr CNKV started to have an additional night of care of the child from late July 2023 in his care as per the consent orders. He stated that there was no change in the care in October 2023.
2. Mr GJVT stated that the calculations that Ms CNKV provided to child support, were incorrect. He stated that he had not checked the dates that Ms CNKV was now relying on because he submitted that she has been marking the dates incorrectly. He stated that he didn't think it was appropriate for the actual days to be provided unless there was some discrepancy. He travelled in July 2023, and the discrepancy was not in the period from October 2023. Mr GJVT stated that the child was in his care for an extra 9 days in the last 3 months due to Ms CNKV travelling overseas and further time in his care because he was undertaking work experience, but he conceded that there was a bit of give and take in the care of the child.
3. Mr GVJT confirmed that the current orders are those made on 2 September 2022 and that the orders have been followed, with some minor changes in the dates and the more recent extra care he had when Ms CNKV was overseas. Mr GJVT stated that if the school holidays used in the calculation were not correct and in fact are higher, then he would be having more care because the care is divided equally during the school holiday period according to the consent orders. He confirmed that an appropriate care period would be a two year period, but not from 15 October 2023 but rather from 24 August 2023.
4. Mr GJVT stated that he made an application for review of the objection decision on 26 May 2024, where he lodged in relation to two issues. The Administrative Appeals Tribunal[17] and a decision was made in relation to his first issue but not in relation to the second issue. As the second issue was not considered, he lodged again on 19 December 2024. He also referred to objections he made with the Registrar on or around March 2024 but these have not been reviewed by the Registrar. Mr GJVT stated that the first review decision thoroughly investigated the matter and the conclusion was that there was no change in care in October 2023 and he agrees with this decision. He has made many calculations of the care percentage and it can be anywhere between 43% and 46% depending on the period and where the special days fall, such as Mother's day, Father's day, Easter and so on, but he accepts 44% as being the correct calculation of his percentage of care, which aligns with his calculations.

Assessing the evidence as to the pattern of care for the children

1. I have considered both the oral evidence at the hearing and the documentary evidence provided in this matter. In respect of the written evidence, I have also taken into account those documents provided by the Registrar, as well as by Ms CNKV and Mr GJVT.
2. In this matter, there is no disagreement between Ms CNKV and Mr GJVT that the care for the child is prescribed by court orders made by consent (consent orders) on 2 September 2022. The first review summarised the care under the consent orders, from the start of Term 3 of 2023, as follows:
   • During school terms (with week 1 starting first Wednesday of term):
     • Week 1: Wednesday and Thursday nights (2 nights)
     • Week 2: Thursday to Sunday nights (4 nights)

• During the 3 shorter school term holidays:
  • In even numbered years, from the conclusion of school on the last day of term until 10 am on the second Sunday;
  • In odd numbered years, from 10 am on the second Sunday of that school holiday period until the commencement of the first day [the child] is to attend school for the new school term.
• During the December/January school holidays:
  • Week on/week off (Mr GJVT first week commencing on the second Sunday of those holidays)
• For special dates where Mr GJVT does not already have care:
  • 2 nights on Father's Day weekend
  • Odd years, 2 nights over Easter
  • Even years, 1 night Christmas Eve
  • Odd years, 1 night Christmas Day
• Care with Ms CNKV if certain events fall on days Mr GJVT otherwise have care:
  • 2 nights on Mother's Day weekend
  • Even years, 2 nights over Easter
  • Odd years, 1 night Christmas Eve
  • Even years, 1 night Christmas Day

1. I accept the summary of the care as outlined above, as it reflects the care as provided for in the consent orders. It was not disputed that the child attends a state school. It was also not in dispute that the care percentages determined from 24 August 2023, in accordance with the consent orders, were 44% to Mr GJVT and 56% to Ms CNKV. This was notified to the Registrar on 5 January 2024. One day after this notification, on 6 January 2024, Ms CNKV notified the Registrar that the care percentage from 15 October 2023 were 38% for Mr GJVT and 62% for Ms CNKV.
2. On 8 January 2024, Ms CNKV contacted a delegate of the Registrar and advised that the previous care percentages (as notified on 6 January 2024) were incorrect and that the care percentage of Mr GJVT were in fact 41% and her care percentage was 59%. In her written submissions, she contends that that Mr GJVT's care percentage was 41%, based on the schedule of school terms[18] for state schools or, in the alternative, Mr GJVT's care percentage was 42% based on the actual care for the same period.[19] Ms CNKV's submissions in this review, was for the care to be determined for a care period over two years from 15 October 2023 to 14 October 2025.
3. As submitted by the Registrar orally at hearing, percentages of care can change along the review continuum. This is particularly the case when the care period prospective, as there is an element of speculation involved with the initial notification of the care change. As is also the case, particularly when a second review of percentage of car is undertaken, the enquiry is almost always retrospective and thus there is the benefit of hindsight in looking at what care has occurred.
4. Such considerations do not necessarily create any jurisdictional issues. It would not be inappropriate to consider material not before the primary decision-maker when the primary decision was made, including material that came into existence after that decision if, there is no temporal element to the decision.[20]
5. As is clear from the history of this matter, in respect of the existing percentages, there was an identifiable change in the percentages of care, which was notified by Mr GJVT, that an increase in the care occurred based on the consent orders from Term 3, 2023. However, the essential question for consideration in this matter, as submitted by Mr GJVT, is to determine whether there was a change to the existing pattern of care on 15 October 2023.
6. Chapter 4.1.3 of the Guide provides information as to what constitutes a 'pattern of care' and states as follows:

In many circumstances, the Registrar will require information about the pattern of care that each parent has of the children. Minor departures from the normal care of the child, such as missing a weekend of care due to illness or work, will not constitute a change to the pattern of care, and will not result in a new care determination.

The Registrar must make a determination of the care a parent or non-parent carer is likely to have, or has had, of the child during the relevant care period. In making a determination, the Registrar may use or request information about past care to form a judgment about likely future care. In doing this, the Registrar may consider patterns of care that have been established in recent months if it is satisfied that the pattern is likely to continue.

1. Mr GJVT submits that there has not been a change in the care from 15 October 2023, and indeed that the care has not changed since 24 August 2023. He stated at hearing that the care has been in accordance with the consent orders, specifically from Term 3, 2023, when his care increased. He noted minor variations in the care, where he missed a day while travelling overseas and also where Ms CNKV missed a day when overseas. Care also changed while the child was undertaking work experience. In his written submissions, Mr GJVT contends that the choice of 15 October 2023 by Ms CNKV specifically excludes the 11 days that the child was in his care from 1 October 2023. Mr GJVT submits that the interpretation of the consent orders will vary between his care percentage to between 43% and 46%, depending on the period of the care that is examined.
2. Both parents agreed at hearing that the care period to be considered should be a two year period, but disagreed as to the date from when such a care period should commence. Ms CNKV states that the actual care should be used to determine the care. The consent orders specify the care of the child during the school term and school holidays. As the parties confirmed that the child attends a state school in [state], I have used the publicly available term dates in the relevant state in which they live. These publicly available records have also been referred to by the parties. Incorporated into the school term period are development days, where a child is not required to attend school on that day. While a child is not required to attend school, they are not included in the school holidays according to the published dates. The development days would be treated in the same way, in my view, as a public holiday might be treated if such a public holiday fell during the school term - a child would not be required to attend school on that particular day but it would nonetheless be a day in the school term.
3. Accordingly, if calculated on the consent orders as described above in paragraph 33, this allows for 12 weeks of school holidays, made up of 6 weeks of summer school holidays and 6 weeks of term school holidays, which leaves 40 weeks for the school terms. Ms CNKV has maintained that the school does not follow these dates, and her calculations exclude development days as not being days within the school term. As explained above, I do not accept this proposition, and find that they form part of the school term dates, but that the child is not required to attend. I am satisfied that there are 12 weeks of holidays and therefore 40 weeks of school term this the average school year in the [state] school system for each year.
4. However, while the parents state that they have complied with the consent orders, there have been variations to the nights in care of the child as per Ms CNKV's evidence and as per Mr GJVT's evidence. The difficulty in the evidence before me is that Ms CKNV has provided calendars for the period from 15 October 2023 until 14 October 2025. Mr GJVT, on the other hand, has provided a calendar for the period from 1 October 2023 until 30 November 2024. The only periods for which each parent has provided corresponding calendars is for the period from 15 October 2023 until 14 October 2024. Ms CNKV's calendar for this period, indicates that Mr GJVT has had care of the child for 152 nights (41.6%) during this period. Mr GJVT's calendar for the same period, shows that he has had care of the child for 155 nights (42.4%). Ms CNKV's calculations of Mr GJVT's care of the child for the two year period is 42%.
5. If I calculate the care period from 1 October 2023 to 30 September 2024, the care percentages of the child, according to Ms CNKV's information would be 43%. This calculation assumes that Ms CNKV accepted that Mr GJVT had the child in his care for an additional 11 nights prior to 15 October 2023. Alternatively, Mr GVJT's calculations for the care period from 1 October 2023 to 30 September 2024 would be 44%. The inclusion of an additional year of care would amount to the same variation of care, based on the parties calculations of the care.
6. I am satisfied that, on the facts before me, that while there may have been divergence from the consent orders and the pattern of care prescribed between August 2023 and October 2023 based on the evidence of Ms CNKV and Mr GJVT respectively, I am not satisfied that the care of the child that was actually taking place, as at the date of the notification on 6 January 2024, did not correspond with the existing percentage of care for the child to Ms CNKV and to Mr GJVT. Therefore, I am not satisfied that the previous care should be revoked and accordingly the care will remain as determined.

Did Mr GJVT seek review of the application within 28 days of the objection decision?

1. I am satisfied, based on my assessment of the evidence above, that while there were minor changes to the pattern of care, when considering the care as outlined in the consent orders, the percentage of care for the child have not changed from the previously determined 56% to Ms CNKV and 44% to Mr GJVT from 15 October 2023. As I am not satisfied that the percentages of care have changed, I find that existing percentage of care should not be revoked.
2. As previously discussed, section 95N of the Collection Act provides that a review decision will have effect from the date the application for review was made if the application was lodged more than 28 days after the objection decision. However, under subsection 95N(2) of the Collection Act, if there are special circumstances that prevented the person from lodging the application within 28 days, the Tribunal may allow for a longer application period.
3. Mr GJVT submitted that he did not apply more than 28 days after the objection decision, but in fact lodged a request for review with the Administrative Appeals Tribunal on 26 May 2024, but this application was not considered. He subsequently lodged another application on 19 December 2024. In supplementary submissions the Registrar has provided a copy of the application made on 26 May 2024. I am satisfied that Mr GJVT sought review of the objection decision of the delegate of the Registrar made on 7 May 2024 within 28 days of that decision on 26 May 2024 but was not considered by the AAT. As I have determined that an application was made within 28 days of the objection decision being made,

1. The Tribunal affirms the decision under review.

[1] T-documents (pages 1 to 343) and supplementary documents ST1 to ST10 (pages 1 to 22); Ms CNKV's Annexures (8 pages) and Mr GJVT's response (4 pages).

[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; MDXJ v Secretary, Department of Social Services [2020] FCA 1767.

[3] Minister for Immigration and Ethnic Affairs v Pochi [1980] FCA 85; (1980) 31 ALR 666, 671 (Smithers J).

[4] Frugtniet v Australian Securities and Investments Commission [2019] HCA 16 at [51] discussing provisions of the Administrative Appeals Tribunal Act 1975 (Cth) which are relevantly indistinguishable to those in the ART Act.

[5] McDonald v Director General of Social Security (1984) 1 FCR 354 at 357.

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

[7] subparagraph 50(1)(b)(ii) of the Act and section 4.1.3 of the Guide.

[8] [2013] AATA 562 at [33].

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

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

[11] Section 95N of the Collection Act.

[17] The predecessor to the current ART which commenced on 14 October 2024.

[20] See Shi v Migration Agents Registration Authority [2008] HCA 31 at [142] to [143]. at [142] - [143]; Child Support Registrar v BKCZ [2023] FCA 1109 at [30].