Ohio Rev. Code § 5729.18
There is allowed a credit against the tax imposed by section 5729.03 of the Revised Code for an insurance company subject to that tax that holds the rights to a tax credit certificate issued under section 122.09 of the Revised Code. The credit shall equal the dollar amount indicated on the certificate. The credit shall be claimed in the calendar year specified in the certificate and in the order required under section 5729.98 of the Revised Code. If the credit exceeds the amount of tax otherwise due in that year, the company may carry forward the excess for not more than five ensuing years, but the amount of the excess credit claimed against the tax for any year shall be deducted from the balance carried forward to the next year.
R.C. § 5729.18