Under section 35 of the Tax Administration Act 1994 [1] , the Commissioner of Inland Revenue has the authority to prescribe forms and electronic formats necessary for administering tax laws. Examples include: IR3 : Individual income tax return IR4 : Companies income tax return IR10 : Financial statements summary Links https://legislation.govt.nz/act/public/1994/0166/latest/DLM351125.html#DLM351125