@Ana1782, yes you do. The ATO website has clear information on this. You will also need an ABN if you havent already got one. You will need to declare your income from Airbnb at the end of the tax year (which you can download from the Airbnb website) and then you can claim deductions against this for power, water and other expenses. There is a calculation based on the ratio of room size to the size of your house. If youre confused, you can phone the ATO - I've always found them very helpful and they can guide you through the process.