External Merits Review The general principle  Where the authorising legislation gives an applicant recourse to an external administrative review procedure, this procedure must be exhausted before judicial review of the administrative action or decision may be sought [NSW Breeding and Racing Stables Pty Ltd v NSW Administrative Decisions Tribunal (2001].  There are two main external administrative review bodies:  The Commonwealth Administrative Appeals Tribunal, governed by the Administrative Appeals Tribunal Act 1977(Cth), has jurisdiction to review many Commonwealth administrative actions and decisions.  The NSW Administrative Decisions Tribunal, governed by the Administrative Decisions Tribunal Act 1997 (NSW), has jurisdiction to review many NSW administrative actions and decisions.  Review by the Commonwealth Administrative Appeals Tribunal (AAT)  The AAT may only review administrative actions and decisions over which it has jurisdiction.  The AAT only has jurisdiction to review a Commonwealth administrative action or decision where the authorising legislation under which that administrative action or decision was purported to be taken or made expressly allows for an applicant to seek review by the AAT.  Section 25 of the Administrative Appeals Tribunal Act 1975 (Cth) states: (1) An enactment may provide that applications may be made to the Tribunal: (a) for review of decisions made in the exercise of powers conferred by that enactment; or (b) for the review of decisions made in the exercise of powers conferred, or that may be conferred, by another enactment having effect under that enactment. (3A) Where an enactment makes provision in accordance with this section for the making of applications to the Tribunal for the review of decisions of a person made in the exercise of a power conferred on that person, that provision of that enactment applies also in relation to decisions made in the exercise of that power