Section 154(1) in The Delhi Municipal Corporation Act, 1957
(1)If the amount of the tax for which a bill has been presented under section 153, is not paid within fifteen days from the presentation thereof, or if the tax on vehicles and animals or the theatre-tax or the tax on advertisements is not paid after it has become due, the Commissioner may cause to be served upon the person liable for the payment of the same a notice of demand in the form set forth in the Seventh Schedule.