Income tax authorities defined as a statutory classification prescribing the official hierarchy and roles for tax administration. Section 116 prescribes the statutory classes of income-tax authorities constituting the administrative machinery under the Act, listing offices from the apex board through tiers of Principal Directors General/Principal Chief Commissioners, Directors-General/Chief Commissioners, Principal Directors/Principal Commissioners, Directors/Commissioners (including appellate roles), Additional and Joint Directors/Commissioners, Deputy and Assistant Directors/Commissioners, Income-tax Officers, Tax Recovery Officers, and Inspectors of Income-tax, thereby defining the official taxonomy for appointment, designation and supervisory organization in tax administration.