Ohio Revised Code Title LVII. Taxation § 5733.261

(A) As used in this section, “qualifying refund overpayment” means an amount received by a taxpayer in excess of a refund or request for payment claimed or made by or on behalf of the taxpayer on a return, report, or other document filed with the tax commissioner.

(B) A taxpayer is not liable for any interest or penalty with respect to the repayment of a qualifying refund overpayment if the taxpayer pays the entire amount of the overpayment to the tax commissioner not later than thirty days after the taxpayer receives an assessment for it. If the taxpayer does not pay the entire amount of the overpayment to the commissioner within the time prescribed by this section, interest shall accrue on the amount of the deficiency pursuant to section 5733.11 of the Revised Code from the day the commissioner issues the assessment until the deficiency is paid.