The online platform (e.g. AirBnb) that facilitates the rental of your residence also provides much of that information to the Australian Taxation Office (ATO). Thereafter, it is a simple matter from them to ensure all taxpayers disclose this rental income in their income tax return.
It is unlikely that many costs of the property during that period will be deductible.
However, a much more significant concern is the loss of full main residence exemption from Capital Gains Tax when the family home is sold. An apportionment for the “business use” of the property will mean some of the “tax-free” gain has become taxable.
How accurate are your records (compared to the ATO who have the on-line platform records)? How complex has it become?
Most taxpayers will forget the details but be surprised by an amended assessment without enough information to dispute ATO assessment.