(1) If the commissioner is unable to certify a tax reduction factor for either class of real property in a taxing unit located in more than one county by the last day of November because the information required under division (G) of section 319.301 of the Revised Code is unavailable, he shall determine and certify estimated tax reduction factors for taxes levied by that taxing unit. The estimated tax reduction factors shall be based on an estimate of the unavailable information.
(2) The commissioner shall also determine and certify estimated composite tax reduction factors for each taxing district by using the tax reduction factors estimated in paragraph (A)(1) of this rule.
(3) Upon receipt of the actual information for a taxing unit that used estimated tax reduction factors, the commissioner shall compute the actual tax reduction factors and the composite tax reduction factors for those taxing districts in which the taxing unit is located. Using these actual tax reduction factors, the commissioner shall compute the taxes that should have been charged and payable against real property in that class for the year for which the estimated tax reduction factors were used.
(4) For the current tax year following the tax year for which the estimated tax reduction factors were used, the commissioner shall add to or subtract from the amount of taxes due for that current year the amount of underpayment or overpayment that resulted in the preceding tax year from the use of the estimated tax reduction factors.
(B) This paragraph applies to all circumstances other than the use of an estimated tax reduction factor as provided in paragraph (A) of this rule.
If the tax commissioner determines that the tax reduction factors or the composite tax reduction factor for either class of real property used on the tax bills for the first half collection of real property taxes was illegal or erroneous, the commissioner may order a correction at any time prior to the mailing of the tax bill for the second half collection of taxes for the same tax year.
The correction shall adjust the tax reduction factors and the composite tax reduction factor used on the tax bills for the second half collected for such year so that the sum of the taxes charged against each parcel of property in the first half collection and the second half collection equals the total amount of taxes that should have been charged against such property for that tax year if a correct and legal tax reduction factor had been used on the tax bill for both collection periods.
(C) If the tax commissioner determines that the tax reduction factors or the composite tax reduction factor for a class of property was illegal or erroneous after the time for a correction permitted under paragraph (B) of this rule, the commissioner shall determine the correct tax reduction factor that should have been used for that year. In computing tax reduction factors for the following tax year, the commissioner shall use, as the net taxes for the year for which the illegal or erroneous tax reduction factors were used, the amount of net taxes for that year if the correct tax reduction factors had been used. Except as provided in division (H) of section 319.301 of the Revised Code and paragraph (A) of this rule, the commissioner shall not adjust the tax reduction factors for such subsequent tax year in order to add to or subtract from the taxes charged and payable for that year any amount that represents an overpayment or underpayment resulting from the use of the illegal or erroneous tax reduction factor in the preceding year.