The Ohio Department of Taxation (the "Department") has issued guidance that it will require married same-sex couples who file joint federal income tax returns to file Ohio income tax returns using a "single" filing status. On October 11, 2013, the Department issued Information Release IT 2013-01, "Filing Guidelines for Taxpayers Filing a Joint Federal Income Tax Return With Someone of the Same Gender" (the "Information Release") and has issued a corresponding schedule, Schedule IT S, "Federal AGI To Be Reported by Same-Gender Taxpayers Filing a Joint Federal Return," for filing with the Ohio IT 1040.

The Information Release applies to original Ohio income tax returns for taxable years 2012 and earlier filed on or after September 16, 2013 and for original Ohio income tax returns filed for taxable years 2013 and after. The Information Release was issued in response to the Internal Revenue Service's statement in Revenue Ruling 2013-17 that it will allow individuals married in states that recognize same-sex marriage to file joint federal income tax returns, beginning on September 16, 2013, regardless of whether the individuals currently are domiciled in a jurisdiction that recognizes same-sex marriage. Revenue Ruling 2013-17 was itself issued in response to the decision by the United States Supreme Court in United States v. Windsor, 570 U.S. ___, 133 S.Ct. 2675 (2013), in which the Supreme Court ruled that § 3 of the federal Defense of Marriage Act (DOMA), 110 Stat. 2419, violated the equal protection clause of the Fifth Amendment of the United States Constitution.

The Information Release provides that individuals who are in same-sex marriages may not use the "married filing jointly" or "married filing separately" status when filing Ohio Form IT 1040 because Article XV, § 11 of the Ohio Constitution allows the state to recognize only marriages between one man and one woman. Because the calculations in the Ohio state income tax return, Form IT 1040, are derived from a taxpayer's federal adjusted gross income, and because a taxpayer's federal adjusted gross income may be determined based on a joint return filed with a same-sex spouse, a same-sex married couple must file two individual Ohio state income tax returns, and must allocate the income from a joint federal return to separate Ohio Forms IT 1040. The Information Release provides that the two individuals shall allocate the federal adjusted gross income reported on their joint federal income tax return using the Form IT S, and each shall file a copy of the completed schedule IT S with their respective IT 1040 return.

Notably, there is no guidance in the Information Release regarding employer withholding on employee wages, and nothing in the Information Release suggests that the amount of income allocated to each individual under Schedule IT S would exceed the total joint income of the couple indicated on their joint federal income tax return. Nor does the Information Release or Schedule IT S differentiate between Ohio residents and nonresidents.