“The AACA is recognised as the national organisation responsible for establishing, coordinating and advocating national standards for the registration of architects in Australia and for the recognition of Australian architects overseas by the relevant Registration Authorities.”
The AACA runs the National Program of Assessment, the pathway for those with experience but without a degree. An applicant needs to show passion and have the competence of an architecture graduate – but from what I’ve heard anecdotally, the bar is set higher than that. Published pass rates in the mid 2010s sat in the high sixties. You might find up to date comments at Reddit.