Every Australian student at the ANU fills out the request for comm support & HECS Help form on the day they enrol. This does not mean you actually have to pay any thing, you just fill in things like your name, DOB, address etc. The census date (which is the deadline to pay your fees) is on like March 31, so basically first years fill out this form at enrolment, then a week later or so, when the info is uploaded into the system, you can pay your HECS fees, or not if you are deferring payment. If there are any issues for you on the day you enrol there are advisers who you sit down with and help you fill it out..