Ohio Business Tax Deadlines (2026)

Next Deadline: May 15 — Form 990 due for nonprofits; Ohio Commercial Activity Tax (CAT) quarterly return due

Federal Tax Deadlines (2026)

Ohio State Tax Deadlines (2026)

Quarterly Estimated Tax Deadlines in Ohio

Ohio follows the federal estimated tax schedule for individual income tax:

The Commercial Activity Tax (CAT) has its own quarterly schedule: May 10, August 10, November 10, and February 10. Annual CAT filers (gross receipts $150,000–$6 million) file once by May 10.

Ohio-Specific Tax Requirements

Ohio is unique among states because it has no traditional corporate income tax or franchise tax. Instead, Ohio imposes the Commercial Activity Tax (CAT) — a gross receipts tax on business activity. For 2026, businesses with taxable gross receipts over $150,000 must register. The CAT rate is 0.26% on gross receipts over $1 million (quarterly filers) with an annual minimum tax of $150 for receipts between $150,000 and $1 million. Recent reforms are phasing down the CAT — check current thresholds.

Ohio's individual income tax uses a graduated rate structure ranging from 0% on the first $26,050 to 3.5% on income over $115,300 (2026 brackets). There's an effective $0 tax on the first $26,050 of income, making it relatively favorable for lower-income earners. Ohio also offers a business income deduction — the first $250,000 of business income is taxed at 0%, with excess taxed at a flat 3%.

One major complexity in Ohio is the municipal income tax system — over 600 Ohio municipalities impose their own income taxes, typically ranging from 0.5% to 3% (2.5% in Columbus, 2.5% in Cleveland, 1.75% in Cincinnati). Most cities require quarterly estimated payments and annual returns. The state's Sales and Use Tax rate is 5.75%, with county additions of 0.75%–2.25%, bringing combined rates to 6.5%–8%. Employers must withhold both state and applicable municipal income taxes.

What Happens If You Miss an Ohio Tax Deadline?

Ohio's late filing penalty is the greater of $50 per month or 5% per month of the unpaid tax, up to a maximum of 50%. A late payment penalty of up to 15% of the unpaid balance may also apply. For the CAT, late filing triggers a penalty of the greater of $50 or 15% of the tax due.

Interest on unpaid taxes accrues at the federal short-term rate plus 5%, recalculated annually — approximately 9%–10% for 2026. Municipal tax penalties vary by city but commonly range from 15%–25% of unpaid tax plus interest.

Ohio provides an automatic extension that matches the federal extension — if you have a valid federal extension, Ohio automatically extends your state filing deadline to October 15. However, you must still pay at least 90% of your Ohio tax liability by April 15 to avoid penalties. CAT returns cannot be extended.

Ohio Department of Taxation

Website: https://tax.ohio.gov/

Phone: (800) 282-1780

Online Filing: https://gateway.ohio.gov/

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