Ohio Rev. Code Ann. § 5528.40

Upon the payment in full of all interest, principal, and charges for the retirement of all highway obligations issued pursuant to Section 2i of Article VIII, Ohio Constitution, and sections 5528.30 and 5528.31 of the Revised Code, the commissioners of the sinking fund shall make a certification of such fact to the clerk of the senate, the clerk of the house of representatives, and the treasurer of state.