(A)   All taxes due the city shall be deemed due and payable at the office of the Collector of Taxes immediately after September 1, and earlier if in the judgment of the Collector of Taxes, the collection of the taxes would be jeopardized by such delay, except that poll taxes shall be paid to the Collector of Taxes on demand, without previous notice.
   (B)   The Collector of Taxes shall give a notice to all persons whose taxes due the city remain unpaid, and if such taxes shall not be paid within 14 days thereafter, together with $.20 for such notice, the Collector of Taxes shall proceed to collect the same according to R.S.A. 80:5.
('71 Code, § 24-2)