XWTH and Child Support Registrar (Child support second review)

This matter concerned a review by the applicant of a decision made by the Social Services and Child Support Division of the Administrative Appeals Tribunal (SSCSD). The SSCSD had revoked existing percentage of care determinations for a child and made new determinations, setting the applicant's percentage of care at 100% from 7 August 2019. The applicant sought review of this decision, specifically concerning the date of effect of the new determinations.

The central legal issue before the court was to determine the correct date from which the SSCSD's percentage of care determinations should take effect. This question hinged on which version of section 54F of the *Child Support (Assessment) Act 1989* (Cth) applied to the circumstances, as there had been two sets of amendments to this provision. The applicant contended that the determination should apply from the date of the change of care (2 February 2015 for the other party), while the SSCSD's decision set the date of effect as the date of notification (7 August 2019).

The court considered the legislative provisions of section 54F, noting that it outlines the circumstances under which the Registrar must revoke a percentage of care determination and specifies when such revocation takes effect. The court found that the second set of amendments to section 54F applied to the case. Under the relevant version of section 54F, the revocation of a determination takes effect either on the day before the Registrar is notified or becomes aware of the matter, or at the end of the interim period, depending on the timing of the notification relative to the change of care day and the interim period. The court's reasoning focused on applying these provisions to the facts to ascertain the correct date of effect for the percentage of care determinations.