Ohio’s business tax structure is unusual and frequently misstated: the state has no corporate income tax, taxes business gross receipts through the Commercial Activity Tax (CAT), and now offers an elective entity-level pass-through tax (IT 4738). Two recent changes — a much higher CAT exclusion and shifted PTE estimate dates — reshape the 2026 calendar.
Ohio Tax Deadlines at a Glance (2026)
Filing | Return Due | Notes |
|---|---|---|
Individual income tax (IT 1040) | April 15, 2026 | Extension to October 15, 2026 |
Pass-through entity (IT 1140 / IT 4708 / IT 4738) | April 15, 2026 | 15th day of 4th month, not March |
Commercial Activity Tax (CAT) | Quarterly | 10th day of 2nd month after quarter |
C Corporations | No Ohio income return | Federal 1120 due April 15; Ohio uses the CAT |
A key correction for CPAs: Ohio pass-through entity returns are due the 15th day of the fourth month — April 15, 2026 for calendar-year filers — not the federal March 16 date. And there is no Ohio corporate income tax return; a C corporation’s Ohio obligation is the CAT on gross receipts.
The CAT Exclusion Rose to $6 Million
The CAT’s taxable-gross-receipts exclusion was raised to $3 million for 2024 and $6 million for 2025 and forward (up from $1 million). Businesses with $6 million or less in Ohio taxable gross receipts now owe no CAT and do not file — a major change that removed most small businesses from the tax. The rate on receipts above the exclusion is 0.26%, and the annual minimum tax was eliminated after 2023. Remaining CAT taxpayers file quarterly only (the annual-filer option ended in 2024).
Ohio’s Elective PTE Tax (IT 4738)
Ohio enacted an elective pass-through entity tax (Form IT 4738) as a federal SALT-cap workaround, effective for tax years beginning on or after January 1, 2022 — so the older claim that Ohio does not tax pass-through income at the entity level is outdated. An electing PTE pays Ohio tax at the entity level and owners receive a refundable credit. Ohio also imposes IT 1140 withholding on nonresident owners. New for tax years beginning in 2026: the Q2 and Q3 estimated-payment dates move up to June 15 and September 15 (Q1 April 15, Q4 January 15 unchanged), affecting both IT 4738 and IT 1140.
Individual Estimates, Municipal Tax, and Penalties
Individual estimated payments (via the Ohio Universal Payment Coupon) are due April 15, June 15, September 15, 2026, and January 15, 2027, required if estimated tax after withholding exceeds $500. Ohio is also a heavy municipal income tax state — many cities collect through RITA or CCA, and businesses may owe the Municipal Net Profit Tax — so CPAs must track city obligations separately from the state return. The certified 2026 interest rate is 7% annually.
CPA Action Steps
Use April 15 for Ohio PTE returns — not the federal March 16 date
Check whether clients fall under the $6M CAT exclusion and can cancel their CAT account
Evaluate the elective IT 4738 for SALT-cap relief; note the new June 15 / September 15 estimate dates
Track municipal (RITA/CCA) obligations independently of the state IT 1040
Confirm CAT quarterly dates and current interest rates against the Ohio Department of Taxation (tax.ohio.gov) before filing.