Thirlwall and Child Support Registrar (Child support)

This matter concerned an application by Ms Thirlwall to the Administrative Appeals Tribunal (the Tribunal) for an extension of time to seek a review of a child support decision made by the Child Support Registrar on 20 October 2017. Ms Thirlwall sought to challenge a decision that adjusted her taxable income for child support purposes to $79,715 for the period 1 October 2017 to 31 December 2018. The application for extension was heard on the papers.

The primary legal issue before the Tribunal was whether to grant Ms Thirlwall's request for an extension of time to apply for a review of the child support objection decision. This required the Tribunal to consider the provisions of the Child Support (Registration and Collection) Act 1988 and the Administrative Appeals Tribunal Act 1975, particularly concerning the prescribed 28-day period for lodging an application for review and the circumstances under which an extension might be granted.

In determining whether to grant the extension, the Tribunal applied the guiding principles established in *Hunter Valley Developments Pty Ltd v Cohen*, which require the Tribunal to be satisfied that it is proper to grant an extension. The Tribunal considered several factors, including the reasons for the delay, the merits of the substantive application, potential prejudice to the other party and the public, and fairness to other applicants. Ms Thirlwall's explanation for the approximately 333-day delay was found to be unsatisfactory, as she was aware of the appeal process and had been advised on multiple occasions to contact the Tribunal. Furthermore, the Tribunal found that her substantive application had little merit, as the Child Support Agency's assumptions regarding her income and financial resources appeared reasonable, and her argument that the evidence used was previously dismissed in court proceedings was not sufficiently substantiated.

The Tribunal concluded that it would not be proper to grant the extension of time. The significant delay, the lack of a satisfactory explanation for that delay, and the limited merits of the substantive application weighed heavily against granting the request. The Tribunal also considered the prejudice to the other party, Mr A, who could reasonably expect the child support assessment to be final after such a lengthy period, and the prejudice to the public interest in maintaining certainty in administrative time limits. Accordingly, the application for an extension of time was refused.