This was copied from the Ohio Dept of Taxation website.
Generally, the owner of the motor vehicle is the one who holds the PUCO or ICC/MC permit. However, the owner of the motor vehicle could be under contract with the PUCO/ICC/MC permit holder. When the owner of a motor vehicle being used in highway transportation for hire is not the permit holder, the owner must provide a copy of the contract, which authorizes the owner to operate the vehicle under the PUCO/ICC/MC permit number.
Any motor vehicle (tractor/trailer rig, pick-up truck, automobile, van, sport utility vehicle and/or motorcycle) could qualify for the TH exemption if it is primarily used in highway transportation for hire.
PS. I thought someone posted a link where it was possible to locate a company's MC number? If anyone has that link I would certainly appreciate your posting it in a reply.