If the taxpayer makes an error or errors in computing the tax on a return, the finance director, or authorized agent, shall correct such error or errors and immediately notify the person filing the return by ordinary mail that such correction has been made. Any additional tax due, together with applicable penalty and interest in accordance with KIBC 3.55.170, for which the taxpayer becomes liable shall be payable immediately by the taxpayer. If the taxpayer makes an error which results in overpayment of tax, the finance director shall allow credit against taxes due on future returns, or shall authorize a refund in accordance with KIBC 3.55.240. [Ord. 96-19 §3, 1996. Formerly §3.30.222].