If for any reason the tax is not paid when due, interest at the rate of 6 percent per annum on the amount of said tax, and an additional penalty of ½ of 1 percent of the amount of the unpaid tax for each month or fraction thereof during which the tax remains unpaid, shall be added and collected. Where suit is brought for the recovery of any such tax, the person liable therefor shall, in addition, be liable for the costs of collection and the interest and penalties herein imposed.
(Ord. 179, 11/7/1966, §9)