Ohio Tax ID Numbers: EIN, Vendor's License, Withholding Account and CAT Number Explained

Searching for an Ohio tax ID number usually means one of two things: the federal number your bank and payroll provider ask for, or a state account number a vendor or agency wants on a form. The problem is that Ohio does not issue a single state tax ID. A typical business ends up with several numbers from four or five different agencies. Each one has its own purpose, its own issuer and its own way of being verified.

This guide covers each number, who issues it, what it is used for and how to confirm it. It is informational content, not legal or tax advice. Your filing obligations depend on your facts, so confirm them with the agency named in each section. If your situation is complicated, such as multiple owners, employees in more than one state, or receipts near the CAT threshold, talk to a qualified CPA or attorney.

Which number do you need?

Most businesses need the federal EIN first, then only the state accounts that match what the business actually does.

Number	Issued by	Needed when	How to get it
Federal EIN	IRS	Federal returns, payroll, Form W-9 requests, most business bank accounts	Directly from the IRS
Vendor's license number	County auditor, under state statute	Before making taxable sales in Ohio	Ohio Business Gateway or county auditor, $50 per fixed place of business
Employer withholding account	Ohio Department of Taxation	When you pay employees wages subject to Ohio withholding	Ohio Business Gateway; confirm the current process with the Department
CAT account	Ohio Department of Taxation	When Ohio taxable gross receipts exceed $6 million (tax year 2025 and later)	Register within 30 days after receipts exceed the threshold
Unemployment employer account	Ohio Department of Job and Family Services (ODJFS)	When you have employees subject to unemployment compensation tax	Confirm requirements with ODJFS
Workers' comp policy number	Bureau of Workers' Compensation (BWC)	When you have employees	Buy coverage from the BWC state fund
Municipal accounts	Each city or village	Where a city or village taxes business net profit or employee wages	Contact each municipality separately

Why "Ohio state employer ID" is confusing

When people search for an Ohio employer identification number or Ohio state employer ID, they usually mean one of two things. The first is the federal EIN, which the IRS issues and which goes on federal returns, Form W-9 and most payroll setups. The second is the Ohio employer withholding account number, which the Ohio Department of Taxation issues for state income tax withholding. Each Ohio account has its own number, and a state account number does not replace the EIN on federal forms. Keep them separate in your records.

Federal EIN from the IRS

The Employer Identification Number is a federal number the IRS assigns to a business. You need it to file federal business tax returns, run payroll and open most business bank accounts. A sole proprietor with no employees can sometimes use a Social Security number for certain purposes, but a CPA can tell you whether an EIN makes more sense for your setup.

Apply directly through the IRS at irs.gov. Third-party sites that charge for "EIN filing" are selling a process you can complete yourself, and some collect personal data along the way. Use the exact legal name from your Ohio articles. The IRS record must match the entity the state recognizes. For an LLC, that is the name on the articles of organization, which cost $99 to file with the Ohio Secretary of State through Ohio Business Central.

Vendor's license number

Ohio has no general state business license. The near universal registration is the vendor's license, which every retailer selling taxable goods or services must obtain before making taxable sales. Counties do not issue a business license. The county auditor issues the sales tax vendor's license under state statute, and the license is tied to sales tax collection under Ohio Revised Code 5739.17.

The fee is $50 per fixed place of business. Before April 9, 2025, the application fee was $25 under House Bill 366. You can apply through the Ohio Business Gateway or directly with the county auditor. Out-of-state sellers registering for a seller's use tax account pay no fee. The state sales tax rate is 5.75%, plus county and transit authority rates that vary by county, so confirm the combined rate for each location with the Ohio Department of Taxation. Suppliers may ask for your vendor's license number when you buy goods for resale.

Employer withholding account

If you pay employees wages subject to Ohio income tax withholding, you need an employer withholding account with the Ohio Department of Taxation. You can register through the Ohio Business Gateway at business.ohio.gov. Check with the Department of Taxation for the current registration process, timing and forms, because the steps change from time to time. The withholding account is how you remit the state tax you take out of employee paychecks.

Many Ohio municipalities and some school districts also levy their own income taxes on wages. Those jurisdictions may require a separate employer account, so check with each city or district where your employees work.

Commercial Activity Tax (CAT) account

Ohio has no corporate income tax and no franchise or annual LLC tax. Businesses above a threshold pay the Commercial Activity Tax instead, a gross receipts tax of 0.26% on Ohio taxable gross receipts. For tax year 2025 and later, only businesses with more than $6 million of Ohio taxable gross receipts owe the CAT or must register. The threshold was $3 million in 2024 and $150,000 before 2024. Businesses below the threshold may never need a CAT account, but confirm your receipts each year.

Registration is required within 30 days after your receipts exceed the $6 million exclusion, under Ohio Revised Code 5751.04. CAT returns are filed quarterly. Financial institutions pay the Financial Institutions Tax instead, and insurance companies pay the insurance premiums tax, so those businesses follow different rules. The CAT account number is issued through the Department of Taxation as part of registration. Confirm the current process at tax.ohio.gov.

Unemployment employer account (ODJFS)

Employers with Ohio employees subject to unemployment compensation tax register with the Ohio Department of Job and Family Services, which assigns an unemployment employer account number. This number is separate from your withholding account. Check with ODJFS for the current registration requirements before your first payroll, because coverage depends on where and how you employ people.

Workers' compensation policy number (BWC)

Ohio is a monopolistic state for workers' compensation. Employers do not buy coverage from private insurers. They buy it from the Bureau of Workers' Compensation state fund, and BWC issues the policy number that appears on your premium statements and claim records. If you plan to hire, contact BWC before your first employee starts. Ask about your classification codes, because premiums depend on how BWC classifies your work.

Municipal accounts

Cities and villages in Ohio tax business net profit under their own rates, and many also levy income tax on wages. Those accounts are separate from anything the state issues, and they are handled city by city. A business with a location in one city and employees who live in another may need to deal with more than one municipal system. Check each city's or village's website, or contact its tax office, to confirm the filing requirement and whether you need a separate account number.

Ohio tax ID lookup: what you can and cannot verify

An Ohio tax ID lookup search often turns up sites promising a company's EIN or state tax number. Be skeptical. The Ohio Secretary of State business search at businesssearch.ohiosos.gov confirms a company's registered name, status and filings, but it is not a source for EINs or state tax account numbers. Do not pay a site to reveal someone else's tax number.

To verify a number a client or vendor gives you, ask for the document it belongs to. For an EIN, request a completed IRS Form W-9. For sales tax purposes, ask for the vendor's license number. Then confirm the account with the agency that issued it. The Department of Taxation handles state tax account questions at tax.ohio.gov.

Order of operations

1. Form the entity first. Articles of organization for an LLC cost $99, and Initial Articles of Incorporation for a for-profit corporation cost $99. Ohio LLCs file no annual report. The articles must name a statutory agent with an Ohio street address, and a post office box does not qualify.
2. Reserve or register a name if needed. A name reservation costs $39 and holds the name for 180 days. A trade name or fictitious name registration also costs $39, and it is filed with the Secretary of State, not the county.
3. Get the EIN from the IRS, using the exact legal name from your articles.
4. Register with the Department of Taxation for a vendor's license if you make taxable sales, a withholding account if you pay Ohio wages, and a CAT account if your receipts exceed $6 million.
5. Before hiring, set up your ODJFS unemployment employer account and your BWC policy.
6. Check municipal requirements for each city or village where you operate or employ people.

Common mistakes

• Using the EIN as your vendor's license number, or the reverse. They come from different agencies and serve different purposes.
• Registering a trade name with the county. Trade names are registered with the Secretary of State.
• Assuming the CAT applies to every business. The $6 million exclusion means most small businesses do not owe it, but receipts can grow past the line.
• Using a legal name on the IRS application that does not match your Ohio articles.
• Paying a third party for an EIN or a state account number you can request directly.

When to get professional help

Talk to a CPA before you choose a business structure or register for the CAT, especially if you have multiple owners, employees in more than one state, or receipts close to $6 million. An attorney should review any operating agreement or ownership arrangement. The Ohio Small Business Development Centers network also offers business advising that can help you sort out the paperwork before you file.

This article is informational only and is not legal, tax or accounting advice. Agency processes, fees and thresholds change. Confirm current amounts and procedures with the issuing agency before you file or rely on them.