Ohio Rev. Code § 3121.031
In any action in which a court support order is issued or modified, the court issuing or modifying the order shall conduct a hearing, prior to or at the time of the issuance of the order, to determine the employment status of the obligor, the obligor's social security number, the name and business address of the obligor's employer, and any other information necessary to enable the court or a child support enforcement agency to issue any withholding or deduction notice described in section 3121.03 of the Revised Code or for the court to issue a court order described in division (C) or (D) of section 3121.03 of the Revised Code. The court, prior to the hearing, shall give the obligor notice of the hearing. The notice shall include the date on which it is given and notice that the obligor is subject to withholding of a specified amount from income if employed and to one or more other types of withholding or deduction requirements described in section 3121.03 of the Revised Code or one or more types of court orders described in division (C) or (D) of section 3121.03 of the Revised Code and that the obligor may present evidence and testimony at the hearing to prove that any of the requirements are not proper because of a mistake of fact.
R.C. § 3121.031