Except as provided in sections 126.301, 1302.98, 1303.16, 1345.10, and 2305.04 and division (B) of section 2305.041 of the Revised Code, an action upon a specialty or an agreement, contract, or promise in writing shall be brought within six years after the cause of action accrued.
Contract in writing
Ohio Rev. Code Ann. § 2305.06, under Jurisdiction; Limitation Of Actions.
Ohio Rev. Code Ann. § 2305.06