Ohio Rev. Code Ann. § 718.87

If a taxpayer that has made the election allowed under section 718.80 of the Revised Code fails to pay any tax as required under sections 718.80 to 718.95 of the Revised Code, or any portion of that tax, on or before the date prescribed for its payment, interest shall be assessed, collected, and paid, in the same manner as the tax, upon such unpaid amount at the rate per annum prescribed by section 5703.47 of the Revised Code from the date prescribed for its payment until it is paid or until the date an assessment is issued under section 718.90 of the Revised Code, whichever occurs first.