Regarding to this topic, i had phoned ATO before. They told me if my income is under 6000 AUD and I do not want tax return. I don't need to claim the tax. Since no matter how much tax you pay will be return to you anyway.原文載於: 背包客棧自助旅行論壇 http://www.backpackers.com.tw/forum/showthread.php?p=1148430
So I don't think you need to, unless you have tax withheld and want it to be returned.
There are two ways to do it,
One, you want your withheld tax be returned (if any). Your right to claim tax return can be up to 5 years. You may choose to do it this financial year or before leaving Australia or do it in the future.
Two, you don't care about your withheld tax. Then you will need to fill up a form to declare that you do not want to claim the tax return.