Ohio Commercial Activity Tax: 5 Essential CAT Rules for CPA Firms

Ohio Commercial Activity Tax is a gross-receipts tax, not an income tax. That distinction changes everything about how it applies. A company with zero net income and $5 million in Ohio gross receipts still owes CAT. A company with slim margins pays the same percentage on revenue as one with strong margins. Businesses that plan their Ohio tax exposure around income tax nexus and don't account for gross-receipts structure can find the CAT waiting for them anyway. At BusAcTa Advisors, our offshore corporate tax preparation team reviews Ohio CAT exposure as part of every multistate business client's state tax analysis. Here is how the five essential rules work.

This post is general information, not tax advice. Ohio CAT thresholds and rules are subject to legislative change. Verify current requirements with the Ohio Department of Taxation before advising clients.

What Is Ohio Commercial Activity Tax?

Ohio Commercial Activity Tax is a privilege tax on the right to do business in Ohio, imposed on gross receipts rather than net income. Ohio enacted the CAT in 2005 through House Bill 66 to replace the Ohio corporate franchise tax. The franchise tax was phased out over several years; the CAT took its place as the primary state-level business tax.

The CAT applies to individuals, corporations, partnerships, LLCs, and other entities with Ohio taxable gross receipts above the exclusion threshold. Crucially, it applies to both Ohio-based businesses and out-of-state businesses with Ohio-sourced receipts. The CAT doesn't require physical presence in Ohio. If a Texas manufacturer ships products to Ohio customers and those receipts exceed the threshold, the CAT applies.

The rate is 0.26% of taxable gross receipts, applied to the total above the exclusion amount. For a business with $10 million in Ohio receipts, the math is straightforward: subtract the exclusion, multiply the remainder by 0.0026. No cost of goods deduction. No expense deduction. No adjustment for losses.

Gross Receipts, Not Income: The Critical Distinction

The most important thing to understand about Ohio Commercial Activity Tax is what the base is. Income taxes are computed on profit. The CAT is computed on revenue. That means:

• A retailer with $8 million in Ohio sales and $7.9 million in cost of goods operates on a 1.25% margin but owes CAT on the full $8 million above the exclusion

• A service firm that lost $300,000 in a given year still owes CAT if Ohio receipts exceeded the threshold

• Businesses that rely on cost deductions or NOL carryforwards to minimize income tax cannot use those tools against the CAT

This structure hits low-margin industries harder than high-margin ones in relative terms. Distributors, retailers, staffing companies, and logistics providers often have significant Ohio revenue with thin margins, making the CAT's gross-receipts base proportionally more expensive for them than a pure income tax would be.

Under the CAT, gross revenue is the tax base. A company with $0 in net income and $5 million in Ohio receipts owes tax. That's structurally different from every state income tax, and multistate planning must account for it separately.

The Exclusion Threshold and 2024 Expansion

Ohio significantly expanded the CAT exclusion threshold under House Bill 33 (2023), effective for tax periods beginning in 2024. Before that change, the first $150,000 of taxable gross receipts was excluded, and businesses paid a tiered minimum tax plus 0.26% on taxable receipts above $1 million.

Under the expanded threshold, the first $3 million in taxable gross receipts is excluded. Businesses with Ohio receipts below $3 million owe no CAT and are no longer required to file. For most small businesses previously covered by the CAT, this eliminated the tax entirely. For larger businesses, the 0.26% rate applies to receipts above the exclusion amount.

The tiered minimum tax structure was also eliminated. Previously, a business paid a minimum regardless of how far above the threshold its receipts were. That floor is gone under the revised framework.

Verify current exclusion amounts with the Ohio Department of Taxation before preparing any CAT return. Ohio's legislature adjusts the CAT periodically, and the threshold in effect at the time of filing determines liability.

Situsing Rules: What Counts as Ohio Receipts

Ohio Commercial Activity Tax applies to Ohio taxable gross receipts, which means only receipts sourced to Ohio. Situsing rules determine whether a particular receipt is Ohio-sourced:

• Tangible personal property. Receipts are sourced to Ohio if property is received in Ohio by the purchaser. Destination-based: where the goods end up, not where they originated.

• Services. Receipts are sourced to Ohio to the extent services are received in Ohio. For a consulting engagement delivered partly to Ohio locations and partly elsewhere, only the Ohio portion counts.

• Rental and royalty income. Sourced to Ohio based on where the property is used or located.

• Interest and dividends. Generally sourced to Ohio based on the domicile of the payor.

The destination-based situsing for tangible property is the primary reason out-of-state businesses get caught by the Ohio CAT. A California company selling equipment to Ohio customers doesn't need an Ohio employee or warehouse to have Ohio-sourced receipts under these rules. Once those receipts exceed the exclusion threshold, a CAT obligation exists.

The Ohio CAT doesn't require physical presence. Destination-based situsing pulls out-of-state businesses into the CAT based on where their customers are, not where the business is located.

Filing Frequency, Forms, and Deadlines

Ohio assigns filing frequency based on Ohio taxable gross receipts:

• Annual filing: Businesses with Ohio taxable gross receipts between the exclusion threshold and $1 million file annually. Annual CAT returns are due May 10 for the prior calendar year.

• Quarterly filing: Businesses with Ohio taxable gross receipts exceeding $1 million file quarterly. Quarterly returns are due May 10, August 10, November 10, and February 10, each covering the preceding calendar quarter.

Both the annual and quarterly CAT returns use Form CAT 12. Ohio requires electronic filing for most CAT taxpayers. New businesses registering for the CAT should confirm their assigned filing frequency at the time of registration rather than defaulting to annual filing.

Ohio Commercial Activity Tax and Municipal Income Taxes

Ohio has no state corporate income tax. The CAT replaced it. But Ohio municipalities impose their own income taxes, and those don't go away because the CAT exists. Businesses operating in Ohio cities face two separate obligations:

• Ohio CAT at the state level, based on gross receipts

• Municipal income tax at the city level, based on Ohio-sourced business income

Major Ohio cities and their approximate income tax rates include Columbus at 2.5%, Cleveland at 2.0%, Cincinnati at 1.8%, and Toledo at 2.25%. These are imposed on net income apportioned to the municipality, not on gross receipts. The CAT and the municipal income tax operate on different bases and can't be offset against each other.

A manufacturing company with a distribution facility in Columbus pays CAT on Ohio gross receipts and Columbus income tax on income attributable to that facility. Both are real obligations. CPA firms advising clients with Ohio municipal operations need to run both analyses independently, not just the state-level CAT.

What Offshore Teams Verify for Ohio Business Clients

When BusAcTa's team reviews Ohio Commercial Activity Tax exposure for a CPA firm's client, five checks appear on every Ohio state analysis:

• Nexus under situsing rules. We confirm whether Ohio-sourced receipts, particularly from tangible property shipped to Ohio customers or services delivered there, cross the current exclusion threshold. Physical presence isn't required, so the analysis starts with receipts, not payroll or property.

• Exclusion threshold comparison. We compare total Ohio receipts against the current exclusion amount to determine whether filing is required and whether quarterly filing is triggered.

• Filing frequency assignment. Receipts above or below $1 million determine quarterly versus annual CAT filing. Misassigning frequency is a common error for businesses entering Ohio for the first time.

• Municipal income tax exposure. We identify Ohio cities where the client has operations, apportion income to those municipalities, and calculate the municipal tax obligation separately from the state CAT analysis.

• Federal deductibility. The CAT is deductible on the federal return as a business expense even though it isn't an income tax. We verify it's captured correctly in federal deductions rather than buried in the Ohio state taxes line.

Conclusion

Ohio Commercial Activity Tax is structured differently from every state income tax your clients pay. The gross-receipts base means no deductions, no expense adjustments, and no loss offsets. Destination-based situsing means out-of-state businesses can owe CAT without a single Ohio employee. The 2024 threshold expansion eliminated most small businesses from the CAT, but businesses above $3 million in Ohio receipts still need full analysis. And the CAT runs alongside, not instead of, Ohio municipal income taxes for clients with Ohio city operations.

If your firm advises multistate clients with Ohio revenue and wants Ohio CAT analysis built into your compliance workflow, schedule a call with BusAcTa Advisors. Our offshore tax preparation team handles CAT exposure reviews, municipal tax apportionment, and Ohio return preparation alongside your firm's tax planning advisory work.