Child Support Registrar v DQFY

Assessment Act 5 The first relevant law is the Child Support (Assessment) Act 1989 (Cth) (Assessment Act). The Registrar noted that the provisions of the Assessment Act in force before the commencement of the Family Assistance and Child Support Legislation Amendment (Protecting Children) Act 2018 (Cth) (Protecting Children Act) on 23 May 2018, which amended provisions in Div 4 of Part 5 of the Assessment Act, apply to these proceedings. That is because the amendments only apply in relation to any "change of care day" occurring on or after 23 May 2018: see Protecting Children Act s 2(1); Sch 1, items 22-39. The Registrar's unchallenged submission was that the relevant change of care day in this case was 1 April 2017. 6 Part 5 of the Assessment Act governs the administrative assessment of child support and relevantly sets out the formulae used by the Registrar in assessing the annual rate of child support payable by a parent for a child for a day in a child support period: s 35A. All of the formulae involve working out each parent's "percentage of care" for the child for the day in a child support period. The phrase "percentage of care" is defined in s 5(1) of the Assessment Act to mean "the responsible person's percentage of care for the child that is determined by the Registrar under Subdivision B of Division 4 of Part 5". That subdivision contains ss 49-54E. Whether s 49 or s 50 applies to determining the percentage of care turns on whether or not a "responsible person" has a "pattern of care". The respondents did not dispute the Registrar's position that s 50 was the relevant provision and that appears to be consistent with the evidence. 7 Section 50 of the Assessment Act relevantly provides as follows: 50 Determination of percentage of care - responsible person has had etc. a pattern of care for a child (1) This section applies if: (a) either of the following applies: (i) an application is made under section 25 or 25A for a parent to be assessed in respect of the costs of the child; (ii) … ; and the Registrar is satisfied that a responsible person for the child has had, or is likely to have, a pattern of care for the child during such period (the care period) as the Registrar considers to be appropriate having regard to all the circumstances; or (b) the Registrar: (i) revokes, under Subdivision C of this Division, a determination of a responsible person's percentage of a care for a child that was made under section 49 or this section; and (ii) is satisfied that the responsible person has had, or is likely to have, a pattern of care for the child during such period (the care period) as the Registrar considers to be appropriate having regard to all the circumstances. (2) The Registrar must determine the responsible person's percentage of care for the child during the care period. (3) The percentage determined under subsection (2) must be a percentage that corresponds with the actual care of the child that the Registrar is satisfied that the responsible person has had, or is likely to have, during the care period. (4) Subsection (3) does not apply if section 51 or 52 applies in relation to the responsible person. 8 The phrase "care period" is defined in s 5(1) of the Assessment Act to include the definitions in s 50(1)(a) and (1)(b)(ii) of the Assessment Act. 9 The "actual care" of a child referred to in s 50(3) is assessed under s 54A of the Assessment Act which relevantly provides as follows: 54A Working out actual care, and extent of care, of a child (1) The actual care of a child that a person has had, or is likely to have, during a care period may be worked out based on the number of nights that the Registrar is satisfied that the child was, or is likely to be, in the care of the person during the care period. (2) The extent of care of a child that a person should have had, or is to have, under a care arrangement during a care period may be worked out based on the number of nights that the child should have been, or is to be, in the care of the person during the care period under the care arrangement. (3) For the purposes of this section, a child cannot be in the care of more than one person at the same time. (4) This section does not limit section 50, 51, 52 or 54. 10 Subdivision C of Div 4 of Part 5 deals with revocation of determinations of percentages of care (ss 54F to 54J). Section 54F relevantly provides as follows: 54F Determination must be revoked if there is a change to the responsible person's cost percentage (1) If: (a) a determination of a responsible person's percentage of care (the existing percentage of care) for a child has been made under section … 50; and (b) … (c) the Registrar or the Secretary is notified, or otherwise becomes aware, that the care of the child that is actually taking place does not correspond with the responsible person's existing percentage of care for the child; and (d) the Registrar is satisfied that the responsible person's cost percentage for the child would change if the Registrar were to determine, under section … 50, another percentage to be the person's percentage of care for the child; and (e) section 54G does not apply; the Registrar must revoke the determination. Note: The Registrar must make a new determination under section 49 or 50 to replace the revoked determination: see paragraph … or 50(1)(b). (2) The revocation of the determination takes effect at the end of: (a) if the Registrar or the Secretary is notified, or otherwise becomes aware, of the matter referred to in paragraph (1)(c) within 28 days after the change of care day for the responsible person: (i) … ; or (ii) otherwise - the day before that change of care day; or (b) … ; or (c) otherwise - the day before the day on which the Registrar or the Secretary is notified, or otherwise becomes aware, of that matter. 11 A "change of care day" is relevantly defined in s 5(1) of the Assessment Act as follows: change of care day for a responsible person for a child means: (a) if a determination of the responsible person's percentage of care for the child has been revoked under Subdivision C of Division 4 of Part 5 - the first day on which the care of the child that was actually taking place ceased to correspond with the responsible person's percentage of care for the child under the determination; or (b) otherwise - the first day on which the care of the child that was actually taking place ceased to correspond with the responsible person's extent of care under a care arrangement that applies in relation to the child. 12 The Registrar submitted that s 54G of the Assessment Act had no application in this case because it deals with the revocation of a determination made under s 50 where a parent has had a pattern of care "that is less than regular care of the child". The phrase "regular care" is defined in s 5(1) and (2) of the Assessment Act as being "at least 14% but less than 35%". Having regard to the "Background" below, the Registrar appears to be correct. 13 Section 54H establishes the circumstances in which the Registrar has a discretion to revoke a determination of a responsible person's percentage of care: 54H Registrar may revoke a determination of a responsible person's percentage of care (1) If: (a) a determination of a responsible person's percentage of care (the existing percentage of care) for a child has been made under section … 50; and (b) … ; and (c) the Registrar or the Secretary is notified, or otherwise becomes aware, that the care of the child that is actually taking place does not correspond with the responsible person's existing percentage of care for the child; and (d) the Registrar is satisfied that, if the Registrar were to determine, under section … 50, another percentage to be the responsible person's percentage of care for the child, the other percentage would not be the same as the person's existing percentage of care for the child; and (e) sections 54F and 54G do not apply; the Registrar may revoke the determination. Note: If the Registrar revokes the determination, the Registrar must make a new determination under section 49 or 50 to replace the revoked determination: see paragraph 49(1)(b) or 50(1)(b). (2) If the Registrar revokes the determination, the revocation takes effect at the end of: (a) if the Registrar or the Secretary is notified, or otherwise becomes aware, of the matter referred to in paragraph (1)(c) within 28 days after the change of care day for the responsible person: (i) … ;or (ii) otherwise - the day before that change of care day; or (b) … ; or (c) otherwise - the day before the day on which the Registrar or the Secretary is notified, or otherwise becomes aware, of that matter. 14 The Registrar submitted that s 54F is engaged (and therefore s 54H does not apply due to s 54H(1)(e)) where a new determination of a percentage of care under s 50 would change a responsible person's "cost percentage". I accept that submission. 15 The phrase "cost percentage" is defined in s 5(1) of the Assessment Act as having the meaning given by s 55C of that Act. Section 55C is contained in Subdiv B of Div 5 of Part 5 of the Assessment Act and it provides as follows: Cost percentages Item Column 1 Percentage of care Column 2 Cost percentage 1 0 to less than 14% Nil 2 14% to less than 35% 24% 3 35% to less than 48% 25% plus 2% for each percentage point over 35% 4 48% to 52% 50% 5 more than 52% to 65% 51% plus 2% for each percentage point over 53% 6 more than 65% to 86% 76% 7 more than 86% to 100% 100%

Registration and Collection Act 16 The second relevant law is the Child Support (Registration and Collection) Act 1988 (Cth) (Registration and Collection Act). Part VII of the Registration and Collection Act contains provisions which deal with internal reviews of the Registrar's decisions. The object of Part VII is "to provide for internal reconsideration of decisions of the Registrar before the decisions may be reviewed by the AAT": s 79E; Div 1 of Part VII. 17 Division 2 of Part VII of the Registration and Collection Act deals with decisions against which objections may be lodged. Section 80A falls in that Division. It provides that either a carer entitled to child support or the liable parent may lodge with the Registrar, or the Secretary, an objection to a "care percentage decision". In this case, the determination to which objection was taken was the July 2018 determination (see [32] below). 18 Section 87, which falls in Div 5 of Part VII, relevantly provides (in s 87(1)) that the Registrar must, within 60 days after an objection was lodged, either disallow the objection or allow it in whole or in part. For ease of reference, I will refer to this Registrar's decision as the "objection decision". In this case, the objection decision was made on 5 September 2018 (see [34] below). 19 Part VIIA of the Registration and Collection Act deals with review by the AAT of decisions made by the Registrar in response to objections. As explained in s 87A: Certain decisions made by the Registrar on reconsideration under Part VII are reviewable by the AAT. A person may apply to the AAT for review of such a decision (an "AAT first review"). The person may apply to the AAT for a further review (an "AAT second review") if the person is dissatisfied with any of the following decisions of the AAT: (a) a decision to refuse an extension of time for a person to make an application for AAT first review; (b) a decision on AAT first review of a care percentage decision; (c) a decision in relation to the date of effect of a decision on AAT first review of a care percentage decision. The rules relating to reviews by the AAT are mainly in the AAT Act, but the operation of that Act is modified in some ways by this Part. The AAT Act allows a person to appeal to a court on a question of law from a decision of the AAT. 20 Division 2 of Part VIIA deals with applications for AAT first reviews. Section 89 allows either: (a) The person who raised the objection the subject of the objection decision made under s 87; or (b) The person who was entitled to be served a copy of the objections and accompanying documents under s 85, to make an application to the AAT for review of the objection decision made under s 87. 21 Division 3 of Part VIIA deals with other matters relating to the AAT first review. 22 Relevantly, s 95D of the Registration and Collection Act provides that the parties to an AAT first review of a decision "include, in addition to the parties referred to in subsection 30(1) of the AAT Act, any other person who, under section 89 of this Act, is a person who may apply for review of the decision". Section 30(1)(b) of the AAT Act provides that "the person who made the decision" is a party to a proceeding before the Tribunal. Relevantly to these proceedings, the person who made the decision under review in the AAT first review is the Registrar. 23 Division 4 of Part VIIA deals with applications for AAT second reviews. Section 96A(b) permits an application to be made for an AAT second review of a decision under s 43(1) of the AAT Act on AAT first review of a care percentage decision. 24 Division 5 of Part VIIA deals with other matters relating to AAT second reviews. Section 97A(2) provides that the AAT Act applies in relation to an application under s 96A(b) (that is, an AAT first review of a care percentage decision) as if the reference in s 30(1)(b) of the AAT Act to who made the decision were a reference to each person who was a party to the relevant AAT first review, other than the applicant for the AAT second review. For reasons set out at [22] above, the Registrar was a party to the AAT first review. 25 Section 97B(1)(a) provides that the AAT Act applies in relation to an application for an AAT second review as if the reference in s 41(2) of the AAT Act to the decision to which the relevant proceedings relate were, where the AAT first review affirmed the "original decision", that "original decision". By force of s 97B(2), the "original decision" is taken to be the objection decision because it was the subject of the AAT first review. 26 On AAT second review, the Tribunal has the same powers and discretions conferred by the Registration and Collection Act on the Registrar in relation to the objection decision and that power must be exercised de novo: see Child Support Registrar v MQMV [2019] FCA 1171 at [48]-[50] (Flick J) and VXQB v Child Support Registrar [2021] FCA 48 at [17]-[18] (Colvin J).

AAT Act 27 The third relevant law is the AAT Act. Relevantly, s 43(1) and ss 44(1) and (1A) of the AAT Act provide as follows: 43 Tribunal's decision on review … Tribunal's decision on review (1) For the purpose of reviewing a decision, the Tribunal may exercise all the powers and discretions that are conferred by any relevant enactment on the person who made the decision and shall make a decision in writing: (a) affirming the decision under review; (b) varying the decision under review; or (c) setting aside the decision under review and: (i) making a decision in substitution for the decision so set aside; or (ii) remitting the matter for reconsideration in accordance with any directions or recommendations of the Tribunal … 44 Appeals to Federal Court of Australia from decisions of the Tribunal Appeal on question of law (1) A party to a proceeding before the Tribunal may appeal to the Federal Court of Australia, on a question of law, from any decision of the Tribunal in that proceeding. Note 1: This Part does not apply to certain migration proceedings (see section 43C). Note 2: A party to a child support first review may in some instances appeal instead to the Federal Circuit Court (see section 44AAA). (1A) Subsection (1) does not apply in relation to a proceeding in the Social Services and Child Support Division, other than a proceeding: (a) that is a child support first review; or (b) for review of an AAT reviewable employer decision within the meaning of the Paid Parental Leave Act 2010. … 28 The Registrar correctly observed that this Court has jurisdiction in this appeal because the notice of appeal raises questions of law as to the application of ss 50 and 54F of the Assessment Act and the respondents do not suggest otherwise. Further, s 44(1) of the AAT Act is not displaced by s 44(1A) because the decision appealed to this Court was made in the General Division of the Tribunal, not the Social Services and Child Support Division.

BACKGROUND 29 This background is taken largely taken from the Registrar's written submissions. 30 On 11 April 2017, the Registrar made a determination that, from 7 March 2017, the "percentage of care" was 27% (father) and 73% (mother) (April 2017 determination). 31 On 6 July 2018, the father notified the Registrar of a change in the actual care of the children. He claimed that he had the children for three nights per week (or 42% the time) from 1 April 2017. 32 Also on 6 July 2018, a delegate of the Registrar: (a) Made a decision (under s 54F of the Assessment Act) to revoke the April 2017 determination; and (b) Made a new determination (under s 50(2) of the Assessment Act) reflecting a change to the percentage of care of the children by each of the father (42%) and the mother (58%) from 1 April 2017 (July 2018 determination). The July 2018 determination therefore had the effect of reducing the child support payable by the father in respect of the children. 33 The July 2018 determination took effect from 6 July 2018, as the father had notified the Registrar that the care of the children that was actually taking place did not correspond with his "existing percentage of care" for them under the April 2017 determination more than 28 days after that change had occurred (ie, from 1 April 2017): see s 54F(1)(c) and (2)(c). 34 On 14 July 2018, the mother objected to the delegate's decision pursuant to s 80A of the Registration and Collection Act. On 5 September 2018, another delegate of the Registrar (referred to in oral submissions as the "objections officer"): (a) Made a decision to allow the mother's application pursuant to s 87(1)(b)(ii) of the Registration and Collection Act (objection decision); (b) Revoked the July 2018 determination under s 54H of the Assessment Act; and (c) Made a determination under s 50(2) of the Assessment Act reflecting a change to the percentage of care of each of the father and the mother to 28% and 72% respectively from 1 April 2017. The objection decision took effect from 6 July 2018. The Registrar contends, and the respondents do not dispute, that the "change of care" day was 1 April 2017. 35 The Details of Objection Decision which accompanied the notification of the objection decision included the following: WE CONSIDERED THE FOLLOWING EVIDENCE IN THE DECISION On 6 July 2018 [the father] advised he had been having 3 nights per week. [The father] advised that he could not remember exactly when this commenced, but it would have been in April 2017. The date of event was keyed as 1 April 2017. [The father] advised this was an agreement between them and that they were working through mediation. On the same day it is documented [the mother] called and agreed to the change in care as advised by [the father]. On the same day the decision was made to accept the change in care as advised by [the father]. On 14 July 2018 an objection was received from [the mother] in writing. On 23 July 2018 in response to the objection lodged by [the mother], [the father] advised: I disagree with the objection from [the mother] and I will follow up with evidence Prior to 6 July 2017, they would have been in my care for 2 nights per week until I moved into my own place. There was a period of about 2.5 weeks where I was in between accommodation, I was staying with a friend until my place became available so at that time I didn't have them for which I will send in evidence From 6 7.17 was when the 3 nights per week started when I moved into my own place. REASONS FOR THE DECISION In order to make a decision to change the record of care for a child we must be satisfied that there has been a change to the ongoing pattern of care (section 49 and 50 of the Child Support (Assessment) Act 1989). The pre-existing pattern of care for [the two children] reflected [the mother] having 265 nights per year or 763 [scil 73] per cent and [the father] having 100 nights per year or 27 per cent from 7 March 2017. During the original decision [the father] advised he had been having 3 nights care per week and that this commenced sometime in April 2017. On speaking with [the mother] it is documented that she agreed with the change in care as advised by [the father]. During the objection process [the mother] advised she agreed to adjust the percentage of care for [the father] to have 2 nights care per week. On speaking with [the father] he advised [that] prior to 6 July 2017, he was having 2 nights care per week until he moved into his own place. [The father] advised there was a period of about 2.5 weeks where he was in between accommodation when he didn't have care and that from 6 July 2017 was when the 3 nights care per week started. Despite a commitment to provide evidence to support his claims of care at the time of writing this report nothing has been received. When reviewing this information, there is agreement to a point in that [the mother] advised [the father's] care is 2 nights per week and [the father] advised from April 2017 to 5 July 2017 his care was 2 nights per week. [The father] advised from 6 July 2017 his care has increased to 3 nights per week. In the absence of evidence from [the father] to support this we have made the decision to reflect the care of [the two children] as [the mother] having 261 nights per year or 72 per cent and [the father] having 104 nights per year or 28 per cent which is based on minimum point of agreement. Before a new care determination can be made, the previous determination must be revoked. Considering the legislation regarding when a care determination can be revoked, we are satisfied that the previous care of [the mother] having 265 nights per year or 763 [scil 73] per cent and [the father] having 100 nights per year or 27 per cent should be revoked from 1 April 2017 under Section 54H of the Assessment Act 1989, as the new level of care will affect the care percentage (but not the cost percentage). The objection is allowed. I understand that the objection officer's decision that there was no change in the "cost percentage" to be because, prior to the July 2018 determination, the father's percentage of care had been 27% and the objection decision had the effect of increasing it by 1% with effect from 6 July 2018, which results in no change to the cost percentage: see [15] above. 36 On 18 September 2018, the father made an application pursuant to s 89 of the Registration and Collection Act for an AAT first review of the objection decision. On 16 November 2018, the Tribunal made a decision pursuant to s 43(1)(a) of the AAT Act, to affirm the objection decision (first review decision). 37 On 30 May 2019, the father made an application, pursuant to s 96A(b) of the Registration and Collection Act, for an AAT second review. On 6 July 2020, a differently constituted Tribunal made a decision pursuant to s 43(1)(c) of the AAT Act (second review decision): see [47] below.

SECOND REVIEW DECISION 38 The Tribunal's decision record (or D) may be summarised as follows. 39 The Tribunal recognised that, in the July 2018 determination, the Registrar determined that the father had 42% of care and the mother had 58% of care of the two children: D[2]. 40 The Tribunal recognised that, in the objection decision (see [34] above), the objections officer allowed the objection and decided that the father had 28% of care and the mother had 72% of care of the two children: D[3]. 41 The Tribunal noted that the first review decision affirmed the objection decision: D[4]. 42 The Tribunal noted that, at the hearing of the AAT second review, it was provided with records of care maintained by each parent for at least a 12 month period commencing on 1 November 2018: D[6]. The records of care are set out in the Court Book at pp 89-101 (father) and 113-119 (mother). I note that the records of care were essentially calendar pages in which the parent marked the days the children spent with their father or mother. Both included entries for the period 1 November 2018 to 31 October 2019. The Tribunal considered the manner of production of the records of care and other evidence provided by the father and mother as to the days of care of the children in that period: D[7]-[10]. 43 The Tribunal said the following in relation to the "care period" to be applied (at D[11]): As explained at the hearing, in deciding this application the Tribunal considers it appropriate to make the assessment in respect of a 12-month "care period" as referred to in the legislation, from 1 November 2018 to 31 October 2019. This period was used as the "care period" because both parents had maintained a record of care for a 12-month period commencing on 1 November 2018. 44 The Tribunal found (at D[12]) that on the balance of probabilities the father's record for that "care period" was accurate and the mother's was not because: (a) [the father] maintained his record of care on a more regular basis than [the mother] as he updated it weekly, whereas [the mother] updated her record of care fortnightly; (b) the evidence given in the statements provided by [the father's] mother and his current partner were broadly consistent with [his] record of care and inconsistent with [the mother's] record of care. The Tribunal explained at the hearing that there was a limit to how much weight the Tribunal had placed on the evidence from [the father's] mother as she did not live in the same house as [the father]; or the evidence of [the father's] current partner, as she did not live in the same house with [him] until on and after July 2019; (c) most importantly, when some of the dates in the record of care for the month of April 2019 were tested with [the father] and [the mother] by the Tribunal during the hearing, [the father] was able to demonstrate (by the production at the hearing of the flight itinerary as detailed in paragraph [8]) that the markings for 7 to 10 April 2019 in his record of care were correct; and [the mother's] were incorrect. This caused the Tribunal to have far greater confidence in the accuracy of [the father's] record keeping in respect of his record of care, over that of [the mother's] record keeping. 45 The Tribunal concluded (at D[13]) that the children were in the father's care as indicated in his record for the period 1 November 2018 to 31 October 2019. From those records, the Tribunal counted that the children were in the father's care for 147 days of that "care period" or 40% of 12 months. It said: Accordingly, the Tribunal finds that [the father] had 40 per cent of the care and [the mother] had 60 per cent of the care of the two children, and is satisfied that this was the case as from at least the date of the [July 2018 determination] until more recently, when a new parenting arrangement was agreed between [the father] and [the mother]. 46 The Tribunal noted that it was informed by the father and mother at the hearing that the effect of the new agreed parenting arrangement was that the father would care for the children three days per week with effect from 3 June 2020. It stated (at D[14]) that: The Tribunal calculates the percentage of care for [the father] to be 42 per cent (rounding down), based on three days per week equalling 156 days per year. 47 In making the second review decision, the Tribunal recorded (at D[15]) that it set aside the decision under review (that is, the objection decision) and, in substitution, it decided that: (a) It revoked the July 2018 determination; (b) With effect from 6 July 2018 to 2 June 2020, the father had a care percentage of 40% and the mother had a care percentage of 60% in relation to their two children. The Registrar described this as the first care percentage determination; and (c) With effect from 3 June 2020, the father had a care percentage of 42% and the mother had a care percentage of 58% in relation to their two children. The Registrar described this as the second care percentage determination.

APPEAL 48 It is the second review decision from which the Registrar appeals pursuant to s 44(1) of the AAT Act.

Questions of law 49 The questions of law on which the Registrar relies are as follows. 50 First, did the Tribunal misconstrue and/or misapply ss 50 and 54F of the Assessment Act? 51 Second, were the Tribunal's findings in respect of the first care percentage determination: (a) Illogical, in the sense that they lacked a logical connection to the evidence before the Tribunal; or (b) Ones for which there was no evidence before the Tribunal? 52 Third, did the Tribunal exceed its jurisdiction or powers on review in making the second care percentage determination?

Grounds 53 The Registrar relied on four grounds. 54 First, the Tribunal made an error of law in its interpretation and application of ss 50 and 54F of the Assessment Act by purporting to make the first care percentage determination in respect of a period other than the "care period" which it identified. The particulars to this ground were as follows: (a) Before making a new determination of percentage of care under s 50 of the Assessment Act, the Tribunal was required to determine, in accordance with s 54F(1) of that Act, whether to revoke the existing care percentage determination because the care of the child that was actually taking place did not correspond with the responsible person's existing percentage of care for the child; (b) In the second review decision at [15(a)], the Tribunal purported to revoke the existing care determination; (c) In making a new determination of the percentage of care under s 50(2) of the Assessment Act, the Tribunal was relevantly required by that provision to "determine the responsible person's percentage of care for the child during the care period" (emphasis in the original); (d) The phrase "care period" is relevantly defined in s 50(1)(b)(ii) of the Assessment Act as "such period … as the Registrar considers to be appropriate having regard to all of the circumstances"; (e) In the second review decision at [11], the Tribunal identified a care period of 1 November 2018 to 31 October 2019; (f) Notwithstanding its identification of that care period in the second review decision at [11], at [15(b)] the Tribunal purported to make a new determination of percentage of care for a period other than the care period that it had identified; and (g) The Tribunal thereby misconstrued and/or misapplied ss 50 and 54F of the Assessment Act. 55 Second, in purporting to make the first care percentage determination in respect of the period commencing on 1 November 2018, the Tribunal misconstrued and/or misapplied ss 50 and 54F of the Assessment Act by considering a care period (1 November 2018 to 31 October 2019) that had no connection with any "change of care day" (as defined in s 5(1) of the Assessment Act) or the date on which the Registrar was notified that the care of the child that was actually taking place did not correspond with the responsible person's existing percentage of care for the child. 56 Third, the Tribunal's findings in respect of the first care percentage determination were: (a) Illogical or irrational, in the sense that there was an absence of logical connection between those findings and the evidence before the Tribunal; or (b) Ones for which there was no evidence before the Tribunal. The particulars of the third ground are as follows: (a) In purporting to make the first care percentage determination, the Tribunal purported to rely on evidence for the period from 1 November 2018 to 31 October 2019 in support of its findings for the following additional periods: (i) 6 July 2018 to 31 October 2018; and (ii) 1 November 2019 and 2 June 2020. (b) In doing so, the Tribunal made findings: (i) That were not logically supported by the evidence before it; or (ii) For which there was no evidence. 57 Fourth, in purporting to make the second care percentage determination, the Tribunal: (a) Made findings of a care period that had not been considered, or was not the subject of findings, by the Tribunal in the AAT first review or any other decision-maker. In so doing, the Tribunal purported to make an original decision, thereby exceeding its jurisdiction or powers on review; and (b) Did not revoke the existing care percentage determination.

SUBMISSIONS 58 The Registrar relied on written and oral submissions prepared by counsel for the Registrar. 59 The respondents did not provide written submissions. The father made some brief oral submissions. The mother declined the opportunity to make submissions.

First question of law: Did the Tribunal misconstrue and/or misapply ss 50 and 54F of the Assessment Act? 60 Counsel for the Registrar addressed the first question of law and the first and second grounds together and submitted that the Tribunal misconstrued or misapplied ss 50 and 54F of the Assessment Act (see [7] and [10] above) in making the first care percentage determination for the following three reasons. 61 First, the Tribunal purported (at D[15(b)]) to make a determination under s 50(2) of the Assessment Act in relation to a care period (6 July 2018 to 2 June 2020) that went beyond the care period identified at D[11] (being 1 November 2018 to 31 October 2019). 62 Counsel for the Registrar submitted that the Tribunal had no power to make the first care percentage determination because the period in respect of which a percentage of care determination can be made under s 50(2) is controlled by the care period referred to in s 50(1)(b) and that construction is fortified by s 50(3). Counsel submitted that, having identified the "care period" of 1 November 2018 to 31 October 2019 at D[11], the Tribunal was authorised to make a determination only in respect of that period. Accordingly, by purporting to make the first care percentage determination the Tribunal exceeded its powers under the Assessment Act and/or it misconstrued s 50(1)(b) and (2), thereby erring in law. 63 In oral submissions, counsel conceded that, for this purpose, the Registrar made no complaint that the care period the subject of the objection decision was a different period from that adopted in D[11] having regard to the breadth of the discretion conferred on the decision-maker under s 50(1)(b)(ii). 64 Second, counsel for the Registrar submitted that the Tribunal did not reach the state of satisfaction described in s 54F(1)(d) of the Assessment Act on a correct understanding of the law and thereby erred: see Graham v Minister for Immigration and Border Protection (2017) 263 CLR 1 at [57] (Kiefel CJ, Bell, Gageler, Keane, Nettle and Gordon JJ). 65 Counsel submitted that: (a) Section 54F(1)(d) required the Tribunal to ask itself whether the "cost percentage" of either of the respondents would change if it made a determination under s 50(2) of the Assessment Act to another percentage of care; (b) The determination under s 50(2) must be one that "corresponds with the actual care of the child that the Registrar is satisfied that the responsible person has had, or is likely to have, during the care period": see s 50(3). So, says the Registrar, reaching the state of satisfaction required by s 54F(1)(d) requires the decision-maker to form a view about the responsible person's "actual care" of the child during the "care period" and how it differs from his or her "existing percentage of care" of the child. This is in a context where the power in s 54F(1) to revoke a determination is enlivened if the Registrar is notified, or becomes aware, that the care of the child that is actually taking place does not correspond with the responsible person's "existing percentage of care" for the child (see s 54F(1)(a) and (c)); and (c) The Tribunal did not engage in that analysis so that it follows that it never lawfully formed a view of either parent's actual care of the children during the period 6 July 2018 to 2 June 2020 (as referred to in [15(b)]). Accordingly, the power to revoke the July 2018 determination was never enlivened. In purporting to revoke the July 2018 determination, the Tribunal exceeded its powers under the Assessment Act. 66 In oral submissions, counsel acknowledged that a possible counter-argument is that the Tribunal found (at D[13]) that the 40% (father) and 60% (mother) care percentages were in place for the period 1 November 2018 to 31 October 2019 and that it was satisfied that this was the case from "at least" the date of the July 2018 determination (being 6 July 2018) until "more recently": see [45] above. To that argument, counsel for the Registrar submitted that the process that was undertaken to reach such a finding was flawed because it lacks any evidentiary foundation (this is further explored in the third ground). 67 Third, counsel submitted that the Tribunal erred in finding that the first care percentage determination should take effect from 6 July 2018. The Tribunal did not engage in any process of identifying a "change of care day" in its reasons. Section 54F(2) at least implicitly requires the Tribunal to do so. It is important because identification of the change of care day impacts the date on which revocation of an existing determination takes effect and also the date on which a new determination should take effect. The change of care day the subject of the earlier decision making processes was 1 April 2017. Counsel suggested that the Tribunal's failure to identify a change of care day was because it focussed its attention on a care period that was different from the care period considered by the Registrar's delegate who made the July 2018 determination. 68 Neither of the respondents made submissions addressing the first question and the first and second grounds.

Second question of law: Were the Tribunal's findings in respect of the first care percentage determination illogical (ie, lacking a logical connection to the evidence) or findings for which there was no evidence before the Tribunal? 69 In relation to the second question and the third ground, the Registrar submitted that: (a) With the exception of the period from 3 June 2020 (which is not the focus of the third ground), the only evidence of the care each respondent provided to their two children comprised the records of care for the "care period" of 1 November 2018 to 31 October 2019 (see [42] above): see D[11]; (b) The Tribunal found (at D[12]) that on the balance of probabilities the father's record of care for that "care period" was accurate and the mother's was not. It therefore found that the children were in his care 40% of the time on the days indicated in his records of care for the period 1 November 2018 to 31 October 2019: D[13]; (c) The Tribunal then said (at D[13]) that it was "satisfied that this was the case from at least the date of the Original Determination [ie 6 July 2018] until more recently, when a new parenting arrangement was agreed between [the father] and [the mother]". The Tribunal therefore determined that each respondent's percentage of care for their children was 40% (father) and 60% (mother) for a period which included 6 July to 31 October 2018 and 1 November 2019 to 2 June 2020: D[15(b)]. Counsel submitted that this finding was "pure speculation"; (d) There was no evidence to suggest that the actual care of the children that each of the respondents had during the periods 6 July to 31 October 2018 or 1 November 2019 to 2 June 2020 was the same as the Tribunal had found for the period 1 November 2018 to 31 October 2019 and any such inference was not available. The Tribunal gave no reasons for drawing the inference. Counsel submitted that it is difficult to see how the Tribunal could have so reasoned in the face of the finding (at D[12]) that there was "a paucity of evidence from which the Tribunal was able to decide [the] application"; and (e) In finding as it did, the Tribunal purported to make a finding which no evidence supported (see Australian Broadcasting Tribunal v Bond (1990) 170 CLR 321 at 355-356 (Mason CJ); VAS v Minister for Immigration and Multicultural and Indigenous Affairs [2002] FCAFC 350 at [13] (Gray, Moore and Weinberg JJ)) or which no logical or rational decision-maker could have made on the evidence (see Minister for Immigration and Citizenship v SZMDS (2010) 240 CLR 611 at [131], [135] (Crennan and Bell JJ). 70 In oral submissions, the father sought to rely on his current partner's statement provided to the Tribunal. Counsel for the Registrar (properly playing "devil's advocate") took the Court to the following material. 71 First, the father's current partner's undated statement which appears in the Court Book at pp 83-85 in which she said: Throughout 2017, 2018 and well into 2019 I have observed and supported [the father] as he moved mountains to see [the two children] at any opportunity. Counsel submitted that while this sentence referred to a period wider than 1 November 2018 to 31 October 2019, there was no reference to the number of days per week in which the father cared for the two children. Counsel went on to note the first sentence of another paragraph from the partner's statement. The paragraph was as follows: However, on the off-peak work season [the father] works from home [the] majority of the time and will organise to have the boys three nights a week at the very least. I recall earlier on that he would have them either Wednesday or Thursday nights (or both) as he took them swimming on Thursdays, and then either Friday/Saturday or Saturday/Sunday nights depending on his work schedule. I recall this because my work is a very structured 9-day fortnight and my weekends with my daughter have always been a very structured every-other-weekend arrangement, and I was able to organise something along the lines of week one: one or two nights with my daughter, and one or two nights with all of us, and week two: one or two nights just [the father] and I and one or two nights the four of us. Counsel conceded that this was a reference to the father caring for the children three nights per week, but said that it was not clear to what period the partner referred. He also noted that the partner said: So, for the first few months of 2019, [the father] would commute around 3 days a week from [suburb] to [different suburb] to pick up the boys. At least one of these days but up to three week days he would then have them at his place overnight … Counsel noted that this was within the "care period" of 1 November 2018 to 31 October 2019. 72 Second, counsel referred to the statement dated 28 November 2019 in which the father's mother said: [The father] has consistently parented [the two children] 2-4 nights per week since July 2017, and often more. Counsel submitted that this was a bald assertion that does not provide a cogent foundation for the Tribunal's primary finding or the inferences that it drew from the evidence before it, given the lack of specificity in relation to the time period and nights the children spent with the father per week.

Third question of law: Did the Tribunal exceed its jurisdiction or powers on review in making the second care percentage determination? 73 Counsel for the Registrar submitted that there were three flaws in the Tribunal's decision to make the second care percentage determination. 74 First, the Tribunal had no power to make that second care determination because it was not made consequent upon the revocation of an existing determination under Subdiv C of Div 4 of Part 5 of the Assessment Act. In the circumstances of the present case, the Tribunal's power to make a determination of a responsible person's percentage of care for a child during a care period under s 50(2) was enlivened, relevantly, only if it revoked under that Subdivision an earlier determination of a responsible person's percentage of care made under s 50. While the Tribunal purported to revoke the July 2018 determination, it was replaced by the first care percentage determination. 75 Second, the Tribunal purported to make a determination in respect of a period that was different from the care period that it identified in D[11]. For reasons given in relation to the first and second grounds, by purporting to do so, the Tribunal exceeded its powers under the Assessment Act and/or it misconstrued s 50(1)(b) and (2), thereby erring in law. 76 Third, the Tribunal erred in law insofar as it purported to make the second care percentage determination consequent upon the receipt of a notification by the respondents of a change in the care of their children under the new parenting arrangement to apply from 3 June 2020: see D[14] and [15(c)]. While the Tribunal could exercise all of the powers and discretions that were conferred on the Registrar in relation to the objection decision (see s 43(1) of the AAT Act), it had no power to receive a new notification from the respondents that the care of their children that actually took place from 3 June 2020 did not correspond with their existing percentages of care. The "notification" or "aware[ness]" referred to in s 54F(1)(c) is the notification to, or the awareness of, the Registrar not the Tribunal (emphasis in submission). Were that not so, and the Tribunal could receive a fresh notification under s 54F(1)(c), the carefully crafted scheme of decision-making by the Registrar under the Assessment Act and Registration and Collection Act would be thwarted. 77 Accordingly, even if, contrary to the reason at [74] above, the Tribunal purported to revoke an existing determination under s 54F(1) consequent upon the receipt of the notification relating to the new parenting arrangement described in D[14], it erred in law. That notification was not made to the Registrar or Secretary as required by s 54(1)(c) and it was not the subject of any earlier decision-making process. As the Tribunal had no authority to exercise the power in s 54F(1), it follows that a precondition to the exercise of the power in s 50(2) was not enlivened in relation to the second care percentage determination: see s 50(1)(b)(i). By purporting to make the second care percentage determination, the Tribunal exceeded its powers under the Assessment Act and s 43(1) of the AAT Act.

CONSIDERATION RELATING TO THE FIRST CARE PERCENTAGE DETERMINATION 78 The Court must not construe an administrative decision maker's decision record "with an eye keenly attuned to the perception of error": Minister for Immigration and Ethnic Affairs v Wu Shan Liang (1996) 185 CLR 259 at 272 (Brennan CJ, Toohey, McHugh and Gummow JJ). Having said that, the decision record for the second review decision is regrettably brief and it does not do some important things. 79 The decision record does not identify the particular provisions of the Assessment Act or the Registration and Collection Act under which the decision was made. Indeed, since there is no express reference to a "change of care day", it is not clear what version of the Assessment Act was thought to be relevant to the second review decision. Since there was no written parenting plan and there is no evidence that there was an "interim period" or a suspension of a determination, I will rely on the version of the Assessment Act on which the Registrar has relied on in its submissions since I understand that amendments subsequently made will have no impact on the assessment of the correctness of the second review decision. 80 The Tribunal's decision record does not refer expressly to important concepts or facts such as: (a) As mentioned, it does not identify the "change of care day" as such; or (b) It does not identify whether it revoked the July 2018 determination under s 54F or s 54H the Assessment Act; (c) It does not identify as such what the "existing percentage of care" was for the purposes of s 54F(1)(a), or when the Registrar was notified or otherwise became aware that the actual care of the children did not correspond with the "existing percentage of care" for the purposes of s 54F(1)(c); (d) The possible impact of a change in the "percentage of care" on a "cost percentage" for the purposes of s 54F(1)(d); (e) The Tribunal did not mention the April 2017 determination; and (f) Although the Tribunal referred to the historical facts of the July 2018 determination and the objection decision and the care percentages determined in the July 2018 determination and the objection decision (at D[2] and [3]), the Tribunal did not record the "change of care day" (being 1 April 2017) or the effective date (being 6 July 2018) for the July 2018 determination and the objection decision. 81 There is also no reference to the facts on the basis of which the Registrar's delegate made the July 2018 determination or the evidence on the basis of which the objections officer made the objection decision. They were summarised in the Details of Objection Decision which was in the documents provided to the Tribunal (see [35] above). Importantly, the decision record did not reveal the following information from the Details of Objection Decision: (a) On 6 July 2018, the father advised that he had been having the children for three nights per week since April 2017 and the "event" was "keyed" as 1 April 2017. This indicates that 6 July 2018 was not the "change of care day" for the July 2018 determination but rather the day that the claimed change was notified to the Registrar and (since that was more than 28 days after the claimed change of care day) it was the effective date of the determination; (b) On 23 July 2018, and relevant to the objection decision, the father said that before 6 July 2017, the children would have been in his care for two nights per week until he moved into his own place. There was a period of about 2.5 weeks where he was at friend's place until his new accommodation was ready and he did not have the children then. However he said that, from 6 July 2017, he had the children three nights per week; (c) The objections officer found that there was a point of agreement between father and mother that for the period from 1 April to 6 July 2017, the father had the children two nights per week and the father did not provide promised evidence concerning the claimed three nights per week from 6 July 2017; (d) In the absence of evidence from the father to support his claim for the period from 6 July 2017, the objections officer decided, on 5 September 2018, to reflect the percentages of care as being 261 nights or 72% (mother) and 104 nights or 28% (father) and that the "change of care" day remained 1 April 2017; (e) The objections officer noted that, before a new care determination could be made, the previous determination must be revoked. The objections officer made the decision to revoke the July 2018 determination under s 54H of the Assessment Act on the basis that the father's existing percentage of care (as found in the April 2017 determination) would, following the revocation of the July 2018 determination and the making of a new determination under s 50, change by 1% to 28%. That change in the percentage of his care would have no impact on the father's (or the mother's) "cost percentage"; and (f) The objections officer found that the effective date of the objection decision was 6 July 2018. I understand that to be because that was the day when the Registrar received notification that actual care did not correspond with the existing percentage of care for the purposes of s 54H(1)(c) of the Assessment Act. As the notification was made more than 28 days after the change of care day, the July 2018 determination ceased to have effect on 5 July 2018 under s 54H(2)(c). 82 Although the Tribunal member gave reasons at D[12] for why it was satisfied that the father and mother had care percentages of 40% and 60% respectively for the "care period" between 1 November 2018 and 31 October 2019, the Tribunal did not (at D[13]) say why it was satisfied that the respondents had the 40:60 percentages of care "from at least the date of the Original Determination", being 6 July 2018, "until recently". The language I have quoted is ambiguous as to what the "care period" was that the Tribunal actually applied for the purposes of the legislation and whether it made a finding of the "change of care day". 83 The Tribunal expressly used the term "care period" with reference to a 12 month period from 1 November 2018 to 31 October 2019 at D[11]-[13]. At D[11], the Tribunal member stated that she was making her assessment with respect to "a 12-month "care period" as referred to in the legislation" (emphasis in the original). Those facts lend some force to the Registrar's submissions that that was the "care period" considered by the Tribunal. 84 I do regard the language of D[11]-[13] as unfortunate. There is no 12 month "care period" referred to in the legislation - a reading of the decision record of the AAT first review at [14] would suggest that that 12 month period derives from administrative guidance. Even though s 50 of the Assessment Act confers a discretion on the Tribunal member as to the "care period" it adopts, consideration of a "care period" which starts to run from the "change of care day" and for so long as necessary is consistent with both the scheme of ss 50 and 54F and the guidance given by the Child Support Registrar in its Child Support Guide as discussed below. 85 Recognising that the first review decision was not the subject of the second review decision, it is useful to note the more transparent (and, with respect, the more appropriate) approach to the issues to which ss 50 and 54F of the Assessment Act give rise which was adopted in the decision record for the first review decision at [11]-[17] (emphasis in the original): 11. Subsection 54F(1) of the Act sets out certain circumstances in which a determination of a percentage of care must be revoked. Specifically, it 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 or children. 12. In this case, the tribunal has determined that a care determination was made under section 50 of the Act from 7 March 2017 and that [the mother] had a percentage of care for [the children] of 72% and that [the father] had a percentage of care of 28%. Therefore, paragraph 54F(1)(a) of the Act is satisfied. [The father] contacted the Department on 6 July 2018 to advise that the care that was taking place for [the children] from 1 April 2017 did not correspond with the existing percentage of care as determined. Therefore, paragraph 54F(1)(c) of the Act is satisfied. 13. The Act also requires that there would be a change in the cost percentage if another percentage of care were determined for [the father] under section 50 of the Act. Section 50 of the Act provides that if the tribunal revokes a determination and is satisfied that a party has had, or is likely to have, a pattern of care of a child, the tribunal must determine the care during the care period. 'Actual care' may be worked out based on the number of nights the child was or will be in the care of the person (subsection 54A(1) of the Act). 14. The tribunal is required to consider what the actual care [the father] and [the mother] have had or are likely to have of [the children] during the care period. The care period is such a period as the Child Support Registrar considers to be appropriate having regard to all the circumstances (section 50 of the Act). The Department's policy in this regard, as set out in Chapter 2.2.1 of the Child Support Guide, is that a care period is generally a 12-month period from the day on which the actual care for a child changed. This policy is not binding on the tribunal but the tribunal has determined that it is appropriate in this matter. In this case, the Department determined that the care period should start from 1 April 2017. However, [the father] did not contact the Department until 6 July 2018. 15. [The father's] submission to the tribunal was that [the children's] care changed from July 2017. In his initial evidence to the Department, it is recorded that the care changed in April 2017. He stated that from July 2017 he had three to four nights per week care of [the children]. He did not keep any records of the care but he thought that it was, on average, three nights per week. [The mother] disagreed and conceded that [the father] had two nights of care per week. [The mother] also did not keep any records of the care during the period. 16. The tribunal has determined that the care for [the father] and [the mother] should remain as determined by the Department and that a new determination of care should not be made. While there may have been changes to the care prior, the tribunal is not satisfied that this has resulted in a higher percentage of care than was being used by the Department. Furthermore, both [the father] and [the mother] did not present any evidence, apart from their respective oral evidence, that there had been a change in the care. Neither has maintained a diary on an ongoing basis of what care was occurring each week and there is no third-party evidence to support the care that was occurring. In the absence of evidence to substantiate that a change in the care has occurred or is occurring, the tribunal has difficulty accepting that a change has occurred and from when the change occurred. 17. Therefore, the tribunal is not satisfied that there has been a change in the care which constitutes a change to the pattern of care, as required under section 50 of the Act. Accordingly, the tribunal has decided not to revoke the existing care determination. 86 Having said that, the language used at D[13] which I have quoted at [82] above suggests that the Tribunal member accepted that the "change of care" day was 6 July 2018 and the Tribunal member stated that she was "satisfied" that the 40:60 percentage split applied from that date. That implies that the "care period" the Tribunal member actually used was from 6 July 2018, which it treated as the "change of care" day, until "more recently" which I understand to mean 2 June 2020. In my view it was open to the Tribunal to so find and ultimately to make the decision that it did. 87 It is true that the Details of Objection Decision indicates that on 23 July 2018, the father advised the Registrar that he commenced care of the children for three nights per week from 6 July 2017, not 1 April 2017. However, in the absence of records for the period between 6 July 2017 and 6 July 2018, it was open to the Tribunal not to accept that 6 July 2017 was the change of care day and to adopt 6 July 2018 as the change of care day because: (a) 6 July 2018 was the day on which the Registrar was first notified of a change in the father's pattern of care. Since that date was more than 28 days after either 1 April 2017 or 6 July 2017, the effective date of any determination made by the Tribunal in the circumstances of this case could not be earlier than that date under s 54F(2) of the Assessment Act; (b) There were no records of care which pre-dated 1 November 2018. Although the records of care before the Tribunal commenced four months after the father first notified the Registrar of the alleged change of the pattern of care, that was a relatively short period of time and the issue of the need for such records was first raised squarely in the first review decision dated 16 November 2018; (c) The father was consistent in his claim made on 6 July 2018 that (at least from the 6 July 2017) he had a pattern of care of at least three nights per week. That claim was disclosed in the Details of Objection Decision which was before the Tribunal; (d) The Tribunal found the father's records of care were more credible than the records of care provided by the mother for good reasons: flight records supported his record of having taken the children on holiday which was inconsistent with the mother's care records and the father's record keeping was more contemporaneous. In my view that supported an inference that, between 6 July 2018 and 1 November 2018, the same pattern of care applied as revealed by the care records, consistently with the father's claims; (e) Although the Tribunal (appropriately) placed little weight on the supporting statements from the father's partner and mother for the reasons given at D[12], they were consistent with the father's claims and for the period from 6 July 2018 to "more recently" - that is, 2 June 2020; and (f) There was nothing before the Tribunal that suggested that the pattern of care changed after 31 October 2019 and before 2 June 2020. 88 The Registrar also complained that the Tribunal member made no finding as to her satisfaction that the father's cost percentage would change if she were to make a determination under s 50 having regard to the requirement in s 54F(1)(d). Again, it is unfortunate that that issue is not addressed in the decision record expressly. However, I do not accept that that is a basis for concluding that it was not considered by the Tribunal member in light of the fact that the July 2018 determination was revoked which would suggest that the power to do so was considered. Unfortunately, as a matter of style, the Tribunal member did not refer to any sections of the Assessment Act or the Registration and Collection Act. Those Acts were only identified under the heading "Legislation" on the front page of the decision record. 89 Further, on any view, given that the change of care percentage adopted in the first care percentage determination was 40:60 percent, if any of the April 2017 determination (27:73 percent), the July 2018 determination (42:58 percent) or the objection decision (28:72 percent) is the benchmark, there would necessarily be a change in the father's (and also the mother's) cost percentage (see [15] above). If the Tribunal member did fail to address the issue, which I doubt, in light of the fact that there must have been a change in the cost percentage, the error cannot have been material and is therefore not jurisdictional in nature: see Hossain v Minister for Immigration and Border Protection (2018) 264 CLR 123. 90 In my view, and contrary to the Registrar's submissions, for reasons given in the preceding paragraphs, there was material before the Tribunal to support the Tribunal's finding with respect to the period between 6 July 2018 and 1 November 2018. Further, contrary to the Registrar's submissions, I do not accept that it was "pure speculation" for the Tribunal to consider that the father's percentage of care continued to be the same between 31 October 2019 to 2 June 2020 in the circumstance where the only relevant change brought to the Tribunal's attention was a new parenting arrangement to take effect from 3 June 2020. I also take into account the evidence given by the father's current partner at [71] and the following evidence that specifically related to a period from June 2019 in which she resided with him. She said in her statement: I can say with utmost certainty that since [the father] has lived with me (early June 2019) that not a week has passed where the boys have stayed any less than three nights a week. For a period of time when [the father] was not working as much (during the 'off-season') [the children] were with us sometimes four nights a week. I can be confident of this, because the noise that three young children and two dogs make, means I cherish the little quiet time I have. And it is not very often at all. 91 I am not satisfied that the first care percentage determination reveals either a misapplication or misconstruction of ss 50 and 54F of the Assessment Act or that it was illogical or it lacked connection to the evidence or that it was made in the absence of evidence. I am not satisfied that any of the first, second or third grounds have been made out.

CONSIDERATION RELATING TO THE SECOND CARE PERCENTAGE DETERMINATION 92 The Tribunal did not exceed its jurisdiction or powers on review in making the second care percentage determination. 93 The way the Registrar has framed its submissions (in terms of a "first care percentage determination" and a "second care percentage determination") aids analysis in many respects, but it is also misleading. Contrary to the Registrar's submissions on the third question and fourth ground, the Tribunal made a decision to revoke the July 2018 determination and then made a replacement determination as it was required to do. That replacement determination related to two time periods having regard to the evidence before the Tribunal. The first time period was from 6 July 2018 to 2 June 2020 and the second time period commenced on 3 June 2020. The Tribunal did not make two separate determinations as contended by the Registrar. 94 The Tribunal stood in the shoes of the objections officer. It had to make the second review decision having regard to the evidence before the Tribunal, not only the evidence that was before the objections officer. I do not understand that proposition to be controversial in light of the fact that the Registrar has taken no issue with the fact that the Tribunal considered the records of care and statements put before the Tribunal, all of which post-dated the objection decision. 95 It is likely that, in most cases, where the Tribunal revokes a determination and makes a new one there will be evidence of care arrangements which were not before the Registrar and those arrangements have no obvious end-date. In that case, the new determination would remain in place until revoked under s 54F or s 54H at some time in the future, after the Registrar becomes aware of a change in care. 96 The bifurcation of the replacement determination in this case was necessitated by the uncontested evidence presented to the Tribunal that the parents had reached a parenting arrangement which would take effect from 3 June 2020. There was no hurdle to the Tribunal being satisfied of the pattern of care that the father and mother were "likely to have" from 3 June 2020 for the purposes of s 50(1)(b)(ii) of the Assessment Act. 97 I note that I have framed what the respondents told the Tribunal concerning the new parenting arrangements as "evidence", not a "notification". I think that is the proper characterisation for the analysis of the third question of law. Further, should there be policy concerns with the decision being made by the Tribunal in light of the new evidence, they should be allayed by the fact that the Registrar is a party to the AAT second review proceedings. Indeed the decision record indicates that the Registrar was represented by counsel and the Department of Human Services at the hearing.

DISPOSITION 98 The appeal on questions of law should be dismissed. I certify that the preceding ninety-eight (98) numbered paragraphs are a true copy of the Reasons for Judgment of the Honourable Justice Farrell.