There are some circumstances by ATO guidelines which will say that it is mandatory to lodged a tax return. It means that you still are ok if you are not lodging your tax return but it depends upon case to case.
There are some incomes which need to lodge with even zero refund. The description as below:
Tax withheld from income under the tax-free threshold
By ATO guidelines, the tax-free threshold is $18,200 or less. However, a taxpayer is entitled to a refund of any tax withheld, even if you have $1 or more tax withheld.
If you really need a refund. so, it’s mandatory to lodge your tax return to receive these amounts.
If you are resident over here for part of the year and your tax free threshold is less than certain threshold, you can use the tool to know whether you need to do lodgement or not.
If you are a foreign resident for tax purposes with $1 or more assessable taxable income, you have to lodge your return.