If any taxpayer fails, neglects or refuses to make and file his or her return as and when required under this chapter, the city finance director is authorized to determine the amount of tax payable, together with any penalty and/or interest assessed under the provisions of this chapter, and by mail to notify the taxpayer of the amount so determined, which amount shall thereupon become the tax and penalty and/or interest and shall become immediately due and payable. (Ord. 02-29 §15, 2002).