(a) The taxpayer making the declaration shall, at the time of the filing thereof, pay to the Administrator at least one-fourth of the estimated annual tax due after deducting the following:
(1) Any portion of such tax to be deducted or withheld at the source pursuant to Section 880.14;
(2) Any credit allowable under Section 880.29; and
(3) Any overpayment of the previous year's tax liability which the taxpayer had not elected to have refunded.
(b) At least a similar amount shall be paid on or before the last day of the month following the seventh and tenth months after the beginning of a taxpayer's taxable year, and on or before the last day of the first month of the succeeding year following the taxable year.
(Ord. 4-75. Passed 1-15-75.)