Ohio Reciprocity Agreements: Indiana, Kentucky, Michigan, Pennsylvania, West Virginia

Ohio sits at the center of one of the most active reciprocity networks in the eastern United States. With five bilateral agreements — covering Indiana, Kentucky, Michigan, Pennsylvania, and West Virginia — Ohio exempts residents of those states from Ohio income tax withholding on wages earned in Ohio. The arrangement covers hundreds of thousands of cross-border commuters in the Cincinnati, Toledo, Youngstown, and Steubenville metro areas, but it also creates complications that are unique to Ohio, most notably the school district income tax and the state's recent bracket-cutting reforms.

This guide explains Ohio's five reciprocity agreements, the IT 4 exemption form, and how the school district income tax interacts with reciprocity. We cite the Ohio Department of Taxation, the Ohio Revised Code, and the school district income tax rules throughout. Use the worked examples to verify your own situation, then run your numbers through our calculator.

Ohio's five reciprocity agreements

Ohio maintains reciprocity with five neighboring states: Indiana, Kentucky, Michigan, Pennsylvania, and West Virginia. Each agreement is codified in Section 5747.05(A) of the Ohio Revised Code, which authorizes the Ohio Tax Commissioner to enter into reciprocal arrangements with other states. The five agreements are bilateral, meaning residents of each partner state are exempt from Ohio income tax withholding on Ohio wages, and Ohio residents working in any of the five states are exempt from that state's withholding under the partner state's reciprocal statute.

The Indiana-Ohio agreement covers commuters in the Toledo and Fort Wayne areas, as well as residents of border counties in both states. The Kentucky-Ohio agreement is one of the most heavily used in the country, covering the Cincinnati metro area where thousands of Kentucky residents commute daily to Ohio employers and vice versa. The Michigan-Ohio agreement covers the Toledo and Detroit commuter corridors, while the Pennsylvania-Ohio agreement covers the Youngstown-Sharon corridor. The West Virginia-Ohio agreement covers smaller but still significant commuter traffic in the Ohio Valley.

Each agreement is structurally identical: wages paid by an employer in one state to a resident of the other state are exempt from withholding in the work state, provided the employee files the proper exemption form. The exemption covers only state-level income tax, not local taxes, school district taxes, or city income taxes.

The IT 4 exemption form

Ohio's primary exemption form is Form IT 4, the Employer Withholding Exemption Certificate. The form is filed by every Ohio employee — both residents and non-residents — to establish withholding parameters. For reciprocity purposes, the non-resident employee files Form IT 4 with the Ohio employer and indicates in the reciprocity section that they are a resident of a reciprocity state. The form is sometimes referenced informally as IT 4-R or IT 4 NR in older materials and out-of-state guidance, but the current Ohio form is simply IT 4.

The reciprocity section of Form IT 4 requires the employee to certify their state of residence under penalty of perjury. The form is filed with the employer's payroll department, not with the Ohio Department of Taxation directly. The employer is required to retain the form on file for the duration of employment and to make it available for audit. The exemption takes effect with the next full pay period after submission and remains in effect until revoked in writing or until the employee terminates employment.

When to file the IT 4: on the first day of employment with an Ohio employer, or as soon as the employee becomes aware that reciprocity applies. Employees who miss the first-day window and see Ohio withholding on their initial paychecks must file a non-resident Ohio return (Form IT 1040) at year-end to claim a refund. The Ohio Department of Taxation typically processes these refunds within eight to twelve weeks of filing.

The Ohio school district income tax

Ohio is one of only a handful of states that allows local school districts to levy an income tax. The Ohio school district income tax (SDIT) is authorized under Chapter 5748 of the Ohio Revised Code and is currently levied by roughly 200 school districts. Rates vary by district and range from 0.25% to 2.0% for 2025, with most districts between 0.75% and 1.5%.

SDIT is structurally separate from the state income tax, and reciprocity does not cover it. However, the SDIT is a resident-only tax: it applies only to residents of a taxing school district, regardless of where they work. Non-residents who work in a taxing school district do not owe SDIT, even if reciprocity does not apply to the state tax. This means reciprocity and SDIT interact in two ways:

For Ohio residents commuting to a reciprocity state (say, a Cincinnati resident working in Kentucky), the employee owes SDIT to their home school district on wages earned in Kentucky. The Ohio employer — if there is one — or the employee directly through estimated payments must cover this liability. For non-residents working in Ohio (say, a Kentucky resident commuting to Cincinnati), the employee owes no SDIT because they are not a resident of any Ohio school district.

The most common SDIT-related mistake is for an Ohio employer to fail to set up SDIT withholding for an Ohio resident who commutes to a reciprocity state. The employer often mistakenly assumes reciprocity eliminates all Ohio tax, when in fact only the state portion is eliminated. Ohio residents in this situation must make estimated SDIT payments to avoid year-end underpayment penalties. The Ohio Department of Taxation's SDI Express system handles these payments.

How Ohio employers handle out-of-state residents

Ohio employers with employees who reside in reciprocity states follow a defined process. On the employee's first day, the employer collects a completed Form IT 4 indicating reciprocity. The employer then sets up payroll so that no Ohio state income tax is withheld, no Ohio school district income tax is withheld (because the employee is a non-resident), and any applicable city income tax is withheld if the work location is in a taxing city. The employer also withholds the residence state's income tax if the employer has payroll registration there; otherwise, the employee is responsible for estimated payments to the residence state.

Ohio city income taxes, which exist in roughly 600 Ohio municipalities, follow their own rules and are not affected by reciprocity. A Kentucky resident working in Cincinnati owes Cincinnati's earnings tax of 1.80% for non-residents in 2025, regardless of reciprocity. The employer must register separately for city withholding, and the city tax is reported in Box 19 of the W-2. Many out-of-state residents are surprised to see Cincinnati withholding even after filing Form IT 4 — reciprocity does not extend to the city tax.

For non-residents working in Ohio, the employer must also file an annual reconciliation (Form IT 941) with the Ohio Department of Taxation and report wages paid to non-resident employees under reciprocity. The reconciliation is due by January 31 of the following year. Employers who fail to file timely face penalties.

Worked examples

Example 1: Kentucky resident working for Ohio employer. A nurse lives in Covington, Kentucky, and commutes to a hospital in Cincinnati, Ohio. She files Form IT 4 with her Ohio employer, claiming reciprocity as a Kentucky resident. The Ohio employer withholds no Ohio state income tax and no Ohio SDIT (because she is not an Ohio resident). The employer does withhold Cincinnati's earnings tax at the 1.80% non-resident rate. Kentucky state income tax of 4% flat is withheld through the employer's Kentucky payroll registration, or the employee makes Kentucky estimated payments. At year-end, she files Kentucky Form 740 and does not file an Ohio state return. She may need to file a Cincinnati local return if any local withholding is incorrect.

Example 2: Indiana resident commuting to Cincinnati. A teacher lives in Aurora, Indiana, and commutes to a school in Cincinnati. He files Form IT 4 with his Ohio employer, claiming reciprocity as an Indiana resident. The Ohio employer withholds no Ohio state income tax, no Ohio SDIT, but does withhold Cincinnati's 1.80% non-resident earnings tax. Indiana state income tax of 3.05% flat, plus the Dearborn County resident tax of approximately 1.00%, is withheld through Indiana payroll registration or paid via estimated payments. At year-end, he files Indiana Form IT-40 and does not file an Ohio state return.

Ohio's 2025 tax changes

Ohio's tax structure has evolved significantly over the past decade. The 2024-2025 biennial budget (House Bill 33, signed in July 2023) consolidated Ohio's income tax brackets and reduced the top rate. For 2024 and 2025, Ohio has two non-zero brackets: 2.75% and 3.5%, with the income thresholds indexed annually for inflation. The Ohio Department of Taxation publishes the inflation-adjusted bracket thresholds in the annual IT 1040 instructions.

The bracket cuts have made Ohio more competitive with its reciprocity partners. Kentucky's 4% flat rate is now higher than Ohio's top 3.5% rate, which has created an incentive for some Kentucky residents to consider relocating across the river. Indiana's 3.05% flat rate remains lower than Ohio's top rate, so Indiana residents commuting to Ohio benefit from reciprocity. The 2024-2025 budget also expanded the Ohio Earned Income Tax Credit and modified several deduction provisions, but these changes do not directly affect reciprocity mechanics.

The Ohio General Assembly continues to debate further rate reductions. Legislation introduced in 2024 has proposed eliminating the state income tax entirely over a multi-year period, though no such proposal had been enacted as of mid-2025. Workers should monitor legislative developments because the underlying rate, while not affecting reciprocity itself, does affect the relative tax burden between Ohio and its reciprocity partners.

What to do if your employer refuses to honor reciprocity

Occasionally, an Ohio employer will refuse to honor reciprocity, either out of ignorance or because of a payroll system limitation. The first step is to cite the specific authority: Ohio Revised Code Section 5747.05(A) and the reciprocity section of Form IT 4. Provide the citation in writing to the payroll contact, and include a copy of the completed IT 4 form. Most refusals are resolved at this stage.

If the employer still refuses, escalate to HR or to a senior payroll manager. Document the request and the employer's response in writing. The Ohio Department of Taxation does not directly enforce reciprocity against employers, but the documentation supports your eventual refund claim. Continue filing IT 4 with each new employer in the meantime.

If the employer ultimately withholds Ohio tax despite the IT 4 on file, you must file a non-resident Ohio return (Form IT 1040) at year-end. Report zero Ohio-sourced wages under reciprocity, claim the withheld tax as a refund, and attach a copy of the IT 4 if requested. Refunds are typically issued within 8 to 12 weeks. You must also file your residence-state return reporting the full wages, and you may need to make estimated payments to the residence state to cover the liability that should have been withheld throughout the year.

Common mistakes

The most common mistake in Ohio reciprocity is filing the IT 4 late or not at all. Workers assume the employer will figure it out, but the employer is legally required to withhold Ohio tax by default. A late IT 4 means the worker must file a non-resident return for a refund, tying up cash for months.

Second is overlooking SDIT withholding. Ohio residents commuting to reciprocity states still owe SDIT to their home school district, and the employer must set this up. Failing to do so leads to underpayment penalties. Conversely, non-residents working in Ohio sometimes see SDIT withholding in error — they should request a refund through the Ohio SDI refund process.

Third is overlooking Ohio city income taxes. Reciprocity does not cover city earnings taxes, and non-residents working in Cincinnati, Columbus, Cleveland, Toledo, or any other taxing city owe the local non-resident rate. The employer must register for city withholding, and the city tax appears in Box 19 of the W-2.

Fourth is failing to file a new IT 4 after a move. A Kentucky resident who relocates to Ohio must file a new IT 4 reflecting Ohio residency within 10 days. The reciprocity exemption no longer applies, and the employer must begin Ohio withholding.

Fifth is assuming reciprocity covers severance or deferred compensation. Reciprocity covers wages paid during employment; severance pay, deferred compensation distributions, and certain post-employment payments may be sourced differently. Workers receiving unusual compensation should consult a tax professional.

What to do next

Pull your most recent pay stub and identify which states and localities have income tax withheld. If you are an Ohio reciprocity commuter and see Ohio state tax withholding despite being a non-resident, file Form IT 4 with your employer immediately. Ohio residents working in reciprocity states should verify that SDIT withholding is set up for their home school district. Workers in Cincinnati, Columbus, or other taxing cities should confirm that city withholding is correct. Run your full-year numbers through our calculator to project your liability under reciprocity, then adjust your W-4 or estimated payments to close any shortfall before year-end.