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

1. Ms Porter and Mr Marriott are the parents of [Child 1] and [Child 2] (the children). This matter concerns their respective percentages of care of the children.
2. According to Child Support records, Mr Marriott contacted Child Support on 12 December 2024 to advise a change in care for the children from 1 January 2024. According to the file note of this date, Mr Marriott reported that he had both children 4 nights per week with no change in the pattern of care during school holidays. Mr Marriott is also recorded as indicating the care was not subject to a court order or written agreement.
3. The recorded care in place as at 1 January 2024 for both children was that Ms Porter had 86% care and Mr Marriott had the remaining 14% care.
4. On 6 January 2025, Ms Porter is recorded as reporting that Mr Marriott had the children on Friday and Saturday nights each week at most. Ms Porter's position essentially was that there was no change in care.
5. A Child Support file note of 8 February 2025 indicates Mr Marriott provided a different version of his care from that previously recorded. Mr Marriott is recorded as advising he had the children 3 or 4 nights a week during school terms and had their care during the entire school holidays. The care during school terms was said to be Friday, Saturday and Sunday nights with some Thursday and Monday night care (for both children) if [Child 1] did not attend school on a Friday or there was a public holiday on a Monday.
6. Mr Marriott provided a statement from his present partner, [Ms A], dated 27 February 2025. [Ms A] wrote:

[Mr Marriott] has had his children [Child 1] and [Child 2] for a minimum of 3 nights per week and all of the school holidays easter and Christmas holidays for over 12 months that I can confirm.

1. Ms Porter provided a statement from a case manager '[Case Manager A]', although [Case Manager A] indicates she was merely repeating what she was told about the care arrangement.
2. On 25 March 2025, Child Support decided Ms Porter had 52% of the children's care and Mr Marriott had the remaining 48% care from 1 January 2024. As the care was advised outside 28 days of the change, Ms Porter's reduced care took effect on 1 January 2024 and Mr Marriott's increased care took effect from 12 December 2024.
3. It appears from a file note of 25 March 2025 that the original decision-maker concluded Mr Marriott had 3 nights of care per week during the 40 weeks of school terms and full care in the 8 weeks comprising the Easter and Christmas school holidays. This was evidently based largely on [Ms A's] brief statement.
4. As Child Support was unable to contact Ms Porter during the decision-making process and the decision notice did not include reasons, it is evident she was not aware of Mr Marriott's claims relating to school holiday care.
5. On 30 April 2025, Ms Porter objected to this decision. Ms Porter is recorded as stating that Mr Marriott had [Child 2] in his care on Friday and Saturday nights but only had [Child 1] on Saturday nights. There is no reference in the file note to school holiday care. Although Ms Porter's statement suggested a different care pattern had emerged at some point for [Child 1], she is recorded as maintaining there was essentially no change in care from that in place before 1 January 2024.
6. On 3 June 2025, Mr Marriott responded by stating he has had 2 nights of care per week of both children since 1 January 2024 and sometimes 3 nights if [Child 1] did not attend school on a Friday or there was a public holiday on a Monday. Mr Marriott reiterated that he had the children in his care over the school holidays, including the Christmas school holiday period.
7. It appears it was not until Child Support's notice of 4 June 2025 to both parties that Ms Porter was aware of Mr Marriott's holiday care claims. Ms Porter's response in this regard was that Mr Marriott had care from 23 December 2024 to 5 January 2025.
8. An objections officer considered the matter on 12 July 2025. Again, Ms Porter's position before the objections officer was essentially that there was no material change in care from that in place before 1 January 2024.
9. The objections officer agreed with the original decision-maker's care percentage determination for [Child 2] but varied the care percentages for [Child 1] from 1 January 2024 to 62% care for Ms Porter and 38% care for Mr Marriott. The objections officer accepted Mr Marriott's claim to have had full care during the school holidays without speaking to the parties. The objections officer agreed with the dates of effect specified in the original decision.
10. The objections officer had regard to care dates Mr Marriott provided from December 2024 to mid-April 2025 as well as various third-party statements. The objections officer's approach involves an unusual mathematical exercise whereby the care percentages found separately for 2024 and 2025 were averaged.
11. Ms Porter sought review by the Tribunal on 14 July 2025 and the matter was heard in Brisbane by telephone on 9 October 2025. The parties provided sworn evidence. Despite providing sworn evidence and being informed of the ramifications of giving false evidence in this context, the parties provided accounts of the care provided that differed in significant respects.
12. I accepted into evidence the following material:
    •  the 'Section 23 Statement and Documents' provided by Child Support, comprising folios 1 to 194 (marked Exhibit 1);
    •  supplementary papers from Child Support folioed 195 to 196 (marked Exhibit 2).
13. Ms Porter attempted to lodge a large volume of photographs in the week prior to the hearing. As the material was not chronologically ordered, was not fully accessible due to the .jpg format used and contained no explanation of the relevance of each photo, I asked the case manager to arrange with Ms Porter to address these issues. Ms Porter responded that she was 'not tech savvy' and that the photographs, which evidently covered a period from July to September 2025, were intended to illustrate the care position from 1 January 2025. In the circumstances, including the late provision of the material, it has not been accepted into evidence.

1. The division of care of an eligible child is regulated by Division 4 of Part 5 of the Child Support (Assessment) Act 1989.[1] Section 49 applies where a parent has no pattern of care of a child and section 50 where there is a pattern of care. Under section 54A the default position is that a pattern of care is determined having regard to nights of care. Section 54D provides that a care percentage that is less than 50% is rounded down.
2. Before a determination under section 49 or 50 can be made in relation to a person, the care determination in place for that person must be revoked. As far as is relevant, a revocation under section 54F can occur if the Registrar were to determine (under section 49 or 50) a different percentage of care and the person's cost percentage would change as a result. Where a change in care does not change a person's cost percentage, the Registrar may revoke the determination in place under section 54H.[2]
3. Relevantly, paragraphs 54F(3)(b) and 54H(3)(b) provide that, if Child Support is informed of a change in care more than 28 days after the change occurred, the revocation takes effect on the day before the change of care day for the person with reduced care and on the day before Child Support is notified (or otherwise becomes aware) of the change for the person with increased care. Under section 55C a person's cost percentage remains at 24% for care between 14% and less than 35%.[3]
4. The wording of subparagraph 50(1)(b)(ii) requires a decision-maker to have regard to the care position at the time they make their determination. The decision-maker will need to determine if a change in care occurred and, if so, consider the care that has already occurred since the change in care and the care that is likely to occur in a period after the decision-maker considers the matter. Setting a care period from the change in care is required as part of this process.
5. In conducting a merits review, the Tribunal takes the place of the original decision-maker and decides the matter completely afresh. It therefore adopts the same position as described above for the original decision-maker. How this is to be understood was clarified by Thomas J in Child Support Registrar v BKCZ [2023] FCA 1109.
6. In essence, this Tribunal can consider evidence and events that have occurred after the original decision-maker made their decision provided it is relevant to the question that was before the original decision-maker. It follows that what care pattern a parent 'has had, or is likely to have' in a care period will depend on the evidence available to the particular decision-maker in the review hierarchy.
7. As Thomas J notes, by the time this Tribunal (standing in the shoes of the original decision-maker) considers a matter, updated evidence will enable it to consider a longer period where the pattern of care involves care that a parent has had in the care period. It may be that the relevant care period has already finished (because there has been a subsequent change in care). In this situation it is only the care the parent has had that is relevant for the Tribunal.

1. At the commencement of the hearing, Ms Porter said her position remained that there was no material change in care from the 86%/14% care split in her favour in place before 1 January 2024.
2. Mr Marriott's position during the hearing was that he has had care of both children at least 2 nights a week during school terms plus care over the entire school holidays. According to Mr Marriott, he noted his school holiday care when he contacted Child Support in December 2024 (and did not say there was no change from the school term care). As to [Ms A's] reference to only the Easter and Christmas school holidays in her statement of 27 February 2025, Mr Marriott indicated he could have had her amend her statement to include all the school holidays. Mr Marriott said he did not advise a change in care earlier as he did not realise the impact of care on his child support liability.
3. Although the parties did not suggest at the hearing that there was any change in care in early 2025 from the care in place in 2024, as noted, Ms Porter informed Child Support on 30 April 2025 that Mr Marriott had [Child 1] in his care only 1 night a week. Further, the written care records each party provided Child Support regarding the care in 2025 (set out below) suggest there may have been a care change involving both children in early 2025. I indicated to the parties that, if a subsequent change in care has occurred, it would need to be considered as a separate matter by Child Support. This is because, as a review body, this Tribunal cannot make original decisions (unless it is necessary to do so to give effect to its review decision).
4. Neither party maintained written records of their care prior to Mr Marriott's contact in December 2024. Unfortunately, the subsequent written records each party purports to have made contemporaneously to mid-April 2025 differ significantly. The parties agreed the Victorian school calendar applies. In rounded terms, the school terms total 40 weeks and the school holidays total the remaining 12 weeks (for a total of 364 days).
5. At the hearing Mr Marriott indicated that, during school terms, he typically collected the children each week on a Friday afternoon from either Ms Porter's home, across the road from one of the children's schools or a place arranged with the children. Mr Marriott then delivered the children to Ms Porter either on a Sunday or Monday morning. It was '50/50' as to either day.
6. According to Mr Marriott, there would be a variation to this pattern if Monday was a school holiday or [Child 1] did not attend school on a Friday. In the first instance, Mr Marriott would have the children on the Sunday night, and in the second instance, he might have them on a Thursday night.
7. Ms Porter indicated she typically had the children at least 5 nights each week during school terms from Sunday night to Thursday night. Ms Porter indicated Mr Marriott did not have Sunday night care unless there was a public holiday on the Monday. There appear from public records to have been only 2 Monday public holidays during the school terms in 2024.
8. Regarding the school holidays, Mr Marriott is adamant he has had the children in his care for the entire school holidays starting from the commencement of the school holidays in December 2023. On the other hand, Ms Porter indicated the care during school holidays was about equal. According to Ms Porter, the care changed one or more times during the holidays.
9. The following table compares the dates Ms Porter and Mr Marriott have provided relating to the children's overnight care in 2025 to 19 April 2025. As noted, each asserts the dates are from contemporaneous written records:

[Child 1] 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 1 to 4, 5, 6, 7 to 11, 12, 13, 14,

19, 20, 21, 22, 23, 27, 28, 29, 15, 16, 17, 18, 19, 20, 21, 22,

[Child 2] 5, 6, 12, 13, 14, 15, 16, 19, 20, 1 to 4, 5, 6, 7 to 11, 12, 13, 14,

21, 22, 23, 27, 28, 29, 30, 31 15, 16, 17, 18, 19, 20, 21, 22,

[Child 1] 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 1, 2, 15, 16, 17, 28

[Child 2] 2, 3, 4, 5, 6, 10, 11, 12, 1, 2, 3, 14, 15, 16, 17, 28

[Child 1] 1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 1, 2, 8, 9, 10, 15, 16, 29, 30

[Child 2] 2, 3, 4, 5, 6, 9, 10, 11, 12, 1, 2, 3, 7, 8, 9, 10, 15, 16, 28,

[Child 1] 1, 2, 3, 4, 6, 7, 8, 9, 10, 11, 13, 5, 6, 10, 11, 12, 13

[Child 2] 1, 2, 3, 6, 7, 8, 9, 10, 11, 13, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 18

1. The dates in bold represent nights where both parties claim to have had the children in their care. There are several dates where neither party claims to have had the children's overnight care. These are 25 and 26 January 2025, 8, 9 and 22 February 2025 and 14 March 2025.
2. Leaving aside the Christmas school holidays for a moment, it seems Mr Marriott does not claim to have had the children in his care every weekend in 2025 prior to the Easter holidays. The Easter school holidays were from Saturday 5 April to Sunday 20 April 2025 (16 days). Nor does he claim to have had either child's care the entire time (or even half the time in [Child 1's] case). Further, although Mr Marriott's evidence was that he collected the children on a Friday afternoon, the weekend dates provided for [Child 1] are Saturday and Sunday nights. Mr Marriott indicates some instances of Friday night care for [Child 2].
3. It appears from Mr Marriott's dates that, consistent with Ms Porter's indication to Child Support on 30 April 2025, he had less care of [Child 2] in 2025 following the Christmas school holidays.
4. In addition to the statement from [Case Manager A] noted earlier, Ms Porter has provided a further 4 third-party statements. In a statement of 18 April 2025, [Mr A] indicates he visits 2 or 3 days a week. [Mr A] states he knows the children see Mr Marriott on a Saturday most weekends. A neighbour, [Neighbour A], states Ms Porter has the children during weekdays, and the children see Mr Marriott 1 or 2 nights a week. Ms Porter said this undated statement was made in April 2025.
5. Ms Porter's present partner, [Partner A], states on 18 April 2025 that Ms Porter has the children 5 or 6 nights a week and that Mr Marriott has care Saturday to Sunday most weekends. [Partner A] states he is the emergency school contact, not Mr Marriott.
6. The last statement is dated 17 April 2025. Although Child Support has redacted some of the identification markers, Ms Porter said it was authored by [Ms B] from [Neighbourhood Group 1]. [Ms B] states that [Child 1] is enrolled in their [named] school program and that Ms Porter ensures he travels safely to and from the program by dropping him off and collecting him from the station every week, Monday through Thursday.
7. Ms Porter said [Child 1] commenced the course on 29 January 2025, which has the same terms as public schools but operates from Monday to Thursday only.

1. As noted, Mr Marriott informed Child Support on 12 December 2024 that he had the children in his care 4 nights a week. That, as it turns out on Mr Marriott's subsequent evidence, was a significant exaggeration. Mr Marriott has whittled his care claim to 2 nights a week for each child with an occasional third day. This claim thus runs contrary to [Ms A's] statement of 27 February 2025 where she states Mr Marriott has at least 3 nights of care a week.
2. Ms Porter's position prior to her statement to Child Support on 30 April 2025 has essentially been that she has the children at least 5 nights a week and that Mr Marriott has 2 nights of care at best on weekends. As noted, Ms Porter was likely unaware before June 2025 that Mr Marriott was claiming to have the full holiday care of the children. Ms Porter's only reference to holiday care before the objections officer considered the matter was that Mr Marriott had the children's care from 23 December 2024 to 5 January 2025. As the objections officer did not speak to the parties, the result is that the holiday care was not adequately ventilated prior to this hearing.
3. Also as noted, Mr Marriott was recorded as initially indicating there was no alteration to the claimed care pattern during the school holidays. Although Mr Marriott now states that he advised he had the children's care during the entire school holidays, I am not convinced he did so. In this regard, [Ms A] in her statement of 27 February 2025 had the opportunity to corroborate Mr Marriott's present claim but did not. Further, Mr Marriott's written record of his care in 2025 reflects care of [Child 2] and [Child 1] for 11 days and 5 days respectively in the 16 days comprising the Easter school holidays.
4. The conflicting written care records the parties provided for 2025 indicate one or both are economical with the truth. Ultimately, this significantly reduces the usefulness of the records provided. Owing to the magnitude of the disparity and lack of detailed information from third parties, it is not possible to reach conclusions about the care that occurred with any precision.
5. I was not as a separate exercise able to reach confident conclusions regarding each party's credibility, although I am inclined to give more weight to Ms Porter's claims as the party who has maintained a more consistent position. It is evident that Ms Porter is the children's primary carer. For example, it is apparent from the parties' evidence at the hearing and [Ms B's] statement that Ms Porter organises the children's schooling, and I understand Mr Marriott's housing situation is somewhat makeshift with the children on mattresses in a caravan when they visit.
6. As best I can make of the conflicting evidence provided, there was a change in care on or around 1 January 2024. Mr Marriott probably had the children in his care from this time around 2 nights a week during school terms in 2024. I am not satisfied Mr Marriott had them in his care for the entire school holidays in 2024 and will adopt Ms Porter's concession that the care would have been about equal.
7. On this basis, adopting a care period of 364 days in 2024, comprising 40 weeks of school terms and 12 weeks of school holidays, Mr Marriott had the children in his care for 122 nights ((40 weeks x 2) + (6 weeks x7)) and Ms Porter had care for the remaining 242 nights. The respective care percentages are 33% for Mr Marriott (rounded down) and 67% care for Ms Porter (rounded up).
8. Under section 55C, Mr Marriott's cost percentage for both children was 24% when he was assessed as having 14% care. The change to 33% for both children does not change the cost percentage (as the care remains less than 35%). Revocations therefore cannot be made under section 54F.
9. I have decided to make revocations under section 54H to reflect the care occurring. Accordingly, as Mr Marriott notified Child Support of a care change more than 28 days after the change occurred, his care percentage in place as at 1 January 2024 is revoked from the day before he notified the change. In Ms Porter's case, the care percentage in place is revoked from the day before the change. As noted, the change in care will not reduce Mr Marriott's child support liability.
10. For completeness, also as noted, if there has been a further change in care in 2025, the parties would need to bring that to Child Support's attention as a separate exercise.

The Tribunal sets aside the decision under review and substitutes the decision that, from 1 January 2024, Ms Porter had 67% care of the children and Mr Marriott had the remaining 33% care. The change takes effect from 1 January 2024 for Ms Porter and 12 December 2024 for Mr Marriott.

[1] All further legislative references are to this Act unless otherwise stated.

[2] Care determinations can also be revoked under section 54G. However, this provision has no present relevance.

[3] This means that a parent's child support liability under the relevant formula in Part 5 will be the same if their care is between 14% and less than 35%.