Time limits for tax assessments set four-year and one-year limitation rules with specified judicial exceptions. An assessment under sections 9 or 10 must be made within the later of four years from the end of the assessment year when the chargeable expenditure was first assessable or one year from filing the return; section 11 assessments follow notice-linked limits (four years from end of assessment year of notice for clause (a), and the later of four years from first assessability or one year from notice for clause (b)). Orders under sections 21-23 permit fresh assessments within four years from the end of the financial year of the order, and assessments to give effect to tribunal or court directions are not subject to the subsections (1) and (2) limitation periods. Stays by court orders are excluded from limitation computation.