An Ohio tax ID is the account number the Ohio Department of Taxation issues when you register your business for a specific state tax, and most Ohio businesses need more than one. Which IDs you need depends on what you sell, whether you have employees, and how much you bring in. You register through either OH|TAX eServices or the Ohio Business Gateway before you begin operating.1Ohio Department of Taxation. Business Registration
Which Ohio Tax Accounts You Need
Ohio doesn’t issue a single, universal business tax number. Instead, each tax has its own account. Three cover the majority of businesses:
- A vendor’s license if you make retail sales of tangible personal property or taxable services in Ohio.2Ohio Department of Taxation. Register for a Vendor’s License or Seller’s Use Tax Account
- An employer withholding account if you maintain an office or transact business in Ohio and pay compensation to any employee.3Ohio Department of Taxation. Employer Withholding
- A Commercial Activity Tax (CAT) account if your Ohio taxable gross receipts exceed $6 million a year.4Ohio Department of Taxation. Commercial Activity Tax (CAT)
Depending on your industry, you may also need registrations for excise taxes, consumer use tax, or the state-administered municipal net profit tax.
If You’re Based Outside Ohio
Out-of-state sellers hit Ohio’s economic nexus threshold once total sales into Ohio exceed $100,000 or reach 200 or more separate transactions in the current or previous calendar year.5Ohio Department of Taxation. Sales and Use Tax Marketplace facilitators face the same thresholds and must count sales made on behalf of the sellers on their platform. Once you cross either line, register for a seller’s use tax account and start collecting Ohio sales tax.2Ohio Department of Taxation. Register for a Vendor’s License or Seller’s Use Tax Account
What Changed With the CAT
Ohio House Bill 33 raised the CAT exclusion sharply. For tax years 2025 and forward, only businesses with more than $6 million in Ohio taxable gross receipts owe the tax, at a rate of 0.26% on receipts above that threshold. The annual minimum tax was eliminated starting in 2024. All CAT filers now file quarterly; the annual filing option is gone.4Ohio Department of Taxation. Commercial Activity Tax (CAT) If your business used to owe CAT under the old thresholds but no longer does, cancel the account rather than continuing to file.
What to Gather Before You Apply
Missing information mid-application usually means starting over. Have these ready:
- Your Federal Employer Identification Number (FEIN), or your Social Security number if you’re a sole proprietor without a FEIN. A FEIN is recommended if you have employees or want to keep your SSN off business filings.6Ohio Department of Taxation. Determine if a FEIN (Federal Employer Identification Number) is Needed
- Your legal business name, matching what’s on file with the Ohio Secretary of State or the federal government.
- Your business start date in Ohio.
- Business location address and mailing address (they can differ).
- Names and addresses of officers, LLC members, or other responsible parties. Ohio requires these because it can hold responsible parties personally liable for certain unpaid taxes.
The paper application for a vendor’s license is Form ST-1, but the Department of Taxation recommends applying electronically since you’ll need an OH|TAX eServices account to file returns regardless.7Ohio Department of Taxation. Application for Vendor’s License to Make Taxable Sales
Where to Register and What It Costs
Ohio splits business tax registration between two connected portals. Sales tax, employer withholding, and most other business tax accounts are handled through OH|TAX eServices.8Ohio Department of Taxation. Register an Account (Business) The Commercial Activity Tax, Financial Institution Tax, motor fuel tax, and the state-administered municipal net profit tax register through the Ohio Business Gateway.9Ohio Business Gateway. Department of Taxation You can move between the two systems once you’re logged in.
The county vendor’s license fee is $50, effective April 2025 under HB 366. The same $50 fee applies to a transient vendor’s license.10Ohio Department of Taxation. Vendor’s License Fee Change Coming Soon Sales tax registration through OH|TAX generates your account number immediately. Other tax types generally process within a few business days. Keep your confirmation; you’ll need each account number every time you file.
What Happens If You Operate Without Registering
Ohio treats unregistered selling as a serious matter, not a paperwork lapse. If the Tax Commissioner finds repeated failures to file returns or pay sales tax, your vendor’s license can be suspended. On day one of the suspension, the Commissioner posts a public notice at every entrance to your business telling customers that no retail sales may occur there.11Ohio Legislative Service Commission. Ohio Revised Code 5739.30 Continuing to do business while suspended is a fourth-degree felony, and each day of operation counts as a separate offense.12Ohio Legislative Service Commission. Ohio Revised Code 5739.99
A vendor who chronically misses deadlines can also be required to post a security bond equal to a full year’s average tax liability, with a $1,000 minimum, within ten days of notice.11Ohio Legislative Service Commission. Ohio Revised Code 5739.30 On the withholding side, interest runs from the original due date, and any underpayment must be resolved within thirty days.13Ohio Legislative Service Commission. Ohio Revised Code 5747.07
Where Personal Liability Comes In
Ohio asks for officer and member names on registration forms for a reason. Sales tax and employer withholding are trust fund taxes: money collected from customers or withheld from employees that legally belongs to the state. The liability shield of a corporation or LLC does not extend to trust fund taxes. A responsible party who had authority to direct payment and instead paid other bills can be held personally liable for the full amount.
This is the most common way an Ohio business failure turns into a personal debt problem. Owners often assume unpaid sales tax or withholding dies with the business. It doesn’t. The Department of Taxation pursues the individuals who had signature authority.
Buying an Existing Business
If you’re purchasing an Ohio business, the seller’s unpaid sales tax can transfer to you. The seller must file a final sales tax return within fifteen days of the sale. As the buyer, you’re required to withhold enough of the purchase price to cover any taxes, interest, and penalties the seller owes, until the seller gives you either a paid receipt or a certificate from the Tax Commissioner showing nothing is due.14Ohio Legislative Service Commission. Ohio Revised Code 5739.14 Skip that step and pay the full price, and you become personally liable for the seller’s unpaid sales tax. No language in the purchase agreement overrides the statute. Request a tax clearance from the seller and hold back funds until you have it.
Keeping Your Account Current or Closing It
Update your records with the Department of Taxation when your address, ownership, or responsible parties change. The Department has an online business address update form for most tax types; employer withholding address changes are handled separately. Stale addresses mean missed notices, and missed notices lead to penalties.
When you close a business or drop below the filing threshold for a tax type, close the account. File a final return for each active account and mark it final. If you don’t, the Department will keep expecting returns, and after enough missed filings it will issue estimated assessments based on your history, generating a bill that may have no connection to what you actually owe. Closing a CAT account matters especially now: many businesses that used to owe CAT no longer do under the $6 million threshold and should cancel rather than file zero-dollar returns indefinitely.4Ohio Department of Taxation. Commercial Activity Tax (CAT)