On or before the expiration of one month after the end of the tax year each taxpayer shall make a return on the form furnished by the City for the entire year showing the gross proceeds of sales or gross income of business, trade or calling, and compute the amount of tax chargeable against him in accordance with the provisions of this article and deduct the amount of quarterly payments (as hereinbefore provided), if any, and transmit with his report a remittance covering the residue of the tax chargeable against him to the City; such return shall be signed by the taxpayer, if made by an individual, or by the president, vice-president, secretary or treasurer of a corporation, if made on behalf of a corporation. If made on behalf of a partnership, joint adventure, association, trust or any other group or combination acting as a unit, any individual delegated by such firm, copartnership, joint adventure, association, trust or any other group or combination acting as a unit shall sign the return on behalf of the taxpayer. Council, for good cause shown, may extend the time for making the annual return on the application of any taxpayer and grant such reasonable additional time within which to make the same as may, by them, be deemed advisable.