In order to apply for a tertiary course a mature age student does not need to base their application on year 12 scores or previous study/ qualifications. Under current entry requirements at Australian universities and TAFE potential students are eligible to apply for courses even if they have not completed secondary school. This is also applicable to some courses run by private RTOs.
The only requirements that tertiary applicants must meet is the minimum entry requirements set by the course provider. This may include for example a folio, an audition, employment experience, Special Tertiary Admission Test (STAT) results, a statement of personal competencies. Examples of the most common form of alternate entry requirements or pathways set by tertiary institutions include: 
To find out the minimum entry requirements for the course that you wish to study contact the course coordinator at the tertiary institution running the course, look at the course handbook produced by the education provider or log onto their website.
Refer to Worksheet 2 - Finding a course that is right for you (worksheet 2 as text 27KB or worksheet 2 as PDF 85 KB) to identify key questions to ask a course coordinator.