Of course you do. All Australian tax residents are required to pay tax on their earnings.
With an ABN, you are a business and so you will need to lodge an annual income tax return. This applies even if your annual income is expected to be below the Tax Free Threshold (TFA) of $18,200 (2021).
However, unlike PAYGW (Pay as You Go Withheld), if you are on an ABN, tax is not deducted as income is earned. For example, if you are a contractor on a building site, you will get the full payment for your worker as tax is not deducted at this point.
So, while you get the full amount you earn, you are still obligated to declare this and pay tax on it. It is good practice to set aside a portion of your income to meet your tax obligations when the financial year ends on June 30.
In addition, if your annual turnover is over $75,000 then you will also need to account for GST.
So, taxes are inescapable – like death or the common cold.