“income year” means the financial year immediately preceding the assessment year and includes—

(a) the period beginning with the date of setting up of a business and ending with the thirtieth day of June following the date of setting up of such business;

(b) in case of an income newly accrued, the period beginning with the date on which it comes into existence and ending with the thirtieth day of June following the date on which such new income comes into existence;

(c) the period beginning with the first day of July and ending with the date of discontinuance of the business or dissolution of the unincorporated body or liquidation of the company, as the case may be;

(d) the period beginning with the first day of July and ending with the date of retirement or death of a partner of the unincorporated body;

(e) the period immediately following the date of retirement, or death of a participant of the unincorporated body and ending with the date of retirement, or death of another participant or the thirtieth day of June following the date of such retirement, or death, as the case may be;

(f) in the case of bank, insurance or ¹[finance company] or any subsidiary thereof, the period of 12 months commencing from the first day of January of the relevant year :

   Provided that subject to the approval of the Deputy Commissioner of Taxes, a different period of 12 (twelve) months may be deemed as income year for a company which is a subsidiary of a parent company incorporated outside Bangladesh, including a subsidiary of that subsidiary, or a holding company or a branch, representative or liaison office thereof, if such company requires to follow a different financial year for the purpose of consolidation of its accounts with the parent company;