Your Ohio school district tax number is the four-digit code the Ohio Department of Taxation uses to route your school district income tax to the right district, and the fastest way to find yours is the department’s online lookup tool, The Finder. Enter your street address, zip code, and a date, and it returns the four-digit code, the current tax rate, and the tax base type your district uses.1Ohio Department of Taxation. The Finder – School District Income Tax – Lookup By Address As of tax year 2026, 214 Ohio school districts impose an income tax, with rates ranging from 0.25 percent to 2 percent of taxable income.2Ohio Department of Taxation. School District Tax Year 2026
How to Look Up Your Four-Digit Code
The Finder is the authoritative source because it reflects current district boundaries, which can shift after annexations or local elections. Older records may not.
If you want a second reference, the Ohio Department of Taxation also publishes a complete alphabetical list of all school districts, their four-digit codes, tax rates, and tax base types each year.3Ohio Department of Taxation. 2025 Ohio School Districts You can also find the number on a prior-year Ohio tax return or on your property tax statement. Use those to confirm, but cross-check against The Finder before filing, especially if you moved.
Your school district for tax purposes is based on where you live, not where you work.4Ohio Department of Taxation. School District Income Tax That surprises people used to municipal income taxes, which can attach to a workplace. The four-digit number on your return must match the district where you lived for the majority of the tax year.3Ohio Department of Taxation. 2025 Ohio School Districts
Check Your District’s Tax Base Before You File
Finding the number is half the job. The other half is knowing which of two tax bases your district uses, because that decides what income gets taxed. The Finder result and the published district list both label each district as either traditional or earned income.3Ohio Department of Taxation. 2025 Ohio School Districts
Traditional Base
Traditional-base districts tax essentially the same income Ohio uses for your state return: wages, interest, dividends, pensions, annuities, IRA distributions, capital gains, self-employment income, unemployment compensation, and most other sources.5Ohio Department of Taxation. Guide to Ohio’s School District Income Tax A retiree living on pension and investment income will owe school district tax under a traditional base.
Earned Income Base
Earned income districts tax only wages, salaries, other compensation, and net self-employment earnings. Interest, dividends, capital gains, pensions, Social Security, and other investment or retirement income are excluded.5Ohio Department of Taxation. Guide to Ohio’s School District Income Tax For many retirees in these districts, the result is no school district tax at all.
Filing under the wrong base is one of the errors the Department of Taxation catches most often, so verify yours before completing your return.
Where the Number Goes: IT 4 and SD 100
Your school district number appears in two places: on the withholding form you give your employer and on the tax return you file each spring.
On Form IT 4 for Withholding
Your employer can only withhold school district tax if you tell them your district. You do that by completing Form IT 4, the Employee’s Withholding Exemption Certificate, which has a section for your school district name and four-digit number.6Ohio Department of Taxation. IT 4 – Employees Withholding Exemption Certificate If you move into a taxing district mid-year, submit an updated IT 4 so withholding starts promptly.4Ohio Department of Taxation. School District Income Tax
At year-end, check that Box 19 and Box 20 on your W-2 separate school district withholding from municipal withholding. If the two are lumped together, you’ll need to break them out when entering the W-2 into your tax software.
On the SD 100
The SD 100 is Ohio’s dedicated School District Income Tax Return. You enter your four-digit number in the designated boxes at the top, and the form uses your Ohio adjusted gross income from the IT 1040 as its starting point.7Ohio Department of Taxation. 2025 Ohio SD 100 – School District Income Tax Return The calculation then follows the traditional or earned income base for that district. The code you enter has to match the district name in the state database exactly; a mismatch triggers automated notices.
You need to file an SD 100 if you lived in a taxing school district for any portion of the year and had income subject to the district’s tax.4Ohio Department of Taxation. School District Income Tax Even if your calculation comes out to zero, the department recommends filing anyway. Skip it and you may receive a failure-to-file notice, an estimated bill, and penalties and interest on top.8Ohio Department of Taxation. Did You Receive a School District Income Tax Failure to File Notice
Situations That Change Which Number You Use
You Moved Between Districts During the Year
Starting with tax year 2023, Ohio uses a consolidated SD 100 that lets you report multiple districts of residence on a single return. The form calculates tax for each taxing district and applies any withholding across your total balance.4Ohio Department of Taxation. School District Income Tax You no longer file a separate SD 100 for each district the way filers had to before 2023. Keep documentation of your move-in date; if you moved from a non-taxing district into a taxing one, you only owe on income earned after the move.
You Were a Nonresident for Part of the Year
For any period you were a nonresident of Ohio, enter “9999” as the school district number on the residency schedule of the SD 100.7Ohio Department of Taxation. 2025 Ohio SD 100 – School District Income Tax Return
You’re a Military Servicemember
Military members are treated as residents of the state on file with the military as their legal residence, regardless of where they are stationed. If that state is Ohio and your home of record is in a taxing school district, the Department of Taxation recommends filing an SD 100.9Ohio Department of Taxation. Military Servicemembers and Ohio Income Taxes
Starting with tax year 2023, married servicemembers and their spouses can choose any of the following as their residence for state income tax purposes: the servicemember’s legal residence, the spouse’s residence, or the servicemember’s permanent duty station.9Ohio Department of Taxation. Military Servicemembers and Ohio Income Taxes A spouse accompanying a servicemember solely because of military orders keeps their original state of legal residence. Whichever residence applies determines which school district number, if any, belongs on the return.
When It’s Due
The SD 100 is due on the same date as your Ohio IT 1040, April 15. A federal extension filed on IRS Form 4868 is accepted automatically for both your Ohio return and your SD 100. The extension only extends the time to file, not the time to pay. If you owe school district tax, pay by the original April deadline to avoid penalties and interest, which can be substantial and compound quickly. That’s another reason the department recommends filing even when you believe you owe nothing.
Mistakes to Avoid
- Using your workplace district instead of your home district. School district income tax is based solely on where you live.4Ohio Department of Taxation. School District Income Tax
- Filing under the wrong tax base. Confirm traditional or earned income on The Finder or the published district list before you file.3Ohio Department of Taxation. 2025 Ohio School Districts
- Assuming no withholding means no liability. Withholding only happens if you submitted an IT 4; its absence tells you nothing about what you owe.
- Forgetting to update your IT 4 after a move. Without a new IT 4, your employer will keep withholding for the old district or none at all.4Ohio Department of Taxation. School District Income Tax
- Confusing school district tax with municipal tax. These are separate taxes with separate returns, and W-2 withholding for each should appear on separate lines.