Belated return filing: permitted up to three months before assessment year end or until assessment completion; late fees apply. A belated return, filed under section 139(4), is a return furnished after the due date under section 139(1). Such returns may be filed any time three months before the end of the relevant assessment year or before completion of the assessment, whichever is earlier. Belated returns attract a late filing fee under section 234F, with a reduced fee applying where the taxpayer's total income does not exceed the statutory threshold for reduced liability.