[(A)] If any of the facts, figures, computations, or attachments required in a taxpayer's report to determine the tax due a municipal corporation must be altered as the result of an adjustment to the taxpayer's federal income tax return, whether the adjustment is initiated by the taxpayer, the internal revenue service, or the tax commissioner, and such alteration affects the taxpayer's tax liability to a municipal corporation, the taxpayer shall file an amended report with the tax commissioner in such form as the commissioner requires. The amended report shall be filed not later than one year after the adjustment has been agreed to or finally determined.

(B) In the case of an underpayment, the amended report shall be accompanied by payment of an additional tax and interest due and is a report subject to assessment under section 5745.12 of the Revised Code for the purpose of assessing any additional tax due under this division, together with any applicable penalty and interest. It shall not reopen those facts, figures, computations, or attachments from a previously filed report no longer subject to assessment that are not affected, either directly or indirectly, by the adjustment to the taxpayer's federal income tax return.

(C) In the case of an overpayment, an application for refund may be filed under section 5745.11 of the Revised Code within the one-year period prescribed for filing the amended report even if it is filed beyond the period prescribed by that section, if it otherwise conforms to the requirements of such section. An application filed under this division shall claim refund of overpayments resulting from alterations to only those facts, figures, computations, or attachments required in the taxpayer's report that are affected, either directly or indirectly, by the adjustment to the taxpayer's federal income tax return unless it is also filed within the time prescribed by section 5745.11 of the Revised Code. It shall not reopen those facts, figures, computations, or attachments that are not affected, either directly or indirectly, by the adjustment to the taxpayer's federal income tax return.

Effective Date: 01-01-2001 .