If the taxpayer shall make any error in computing the tax assessable against him, the Recorder shall correct such error or re-assess the proper amount of taxes and notify the taxpayer of his action by mailing to him promptly a copy of the corrected assessment, and any additional tax for which such taxpayer may be liable shall be paid within ten days after the receipt of such statement.
If the amount already paid exceeds that which should have been paid on the basis of the tax so recomputed, the excess so paid shall be immediately refunded to the taxpayer upon the requisition of the Recorder, and shall be payable out of any funds available for the purpose. The taxpayer may, at his election apply an overpayment credit to taxes subsequently accruing hereunder.