Section 167 — Income Tax Assessment Act 1936: Default assessment

If: (a) any person makes default in furnishing a return; or (b) the Commissioner is not satisfied with the return furnished by any person; or (c) the Commissioner has reason to believe that any person who has not furnished a return has derived taxable income; the Commissioner may make an assessment of the amount upon which in his or her judgment income tax ought to be levied, and that amount shall be the taxable income of that person for the purpose of section 166.