If any taxpayer fails to apply for license, or make his return, or to pay the fee or tax therefor, or any part thereof, within three days after the same shall have become due, the finance director shall ascertain the amount of the fee or tax or installment thereof due and shall notify such taxpayer thereof, who shall be liable therefor in any suit or action by the city for the collection thereof. The finance director shall also notify the city attorney in writing of the name of such delinquent taxpayer and the amount due from him and said officer shall, with the assistance of the finance director, collect the same by any appropriate means or by suit or action in the name of the city. [Code 1980 at § 15.04.140].