If it shall appear that an amount of tax has been paid which was not due under the provisions of this chapter, whether as the result of a mistake of fact or an error of law, then such amount shall be credited against any tax due, or to become due, under this chapter from the taxpayer who made the erroneous payment; provided, that no amounts erroneously paid more than one year prior to the filling of a claim therefor shall be so credited.
(Ord. 87-12 § 7 ,1986).