How to Find a Business's Tax ID Number

Where to Look for a Business Tax ID

A business tax ID number—formally called an Employer Identification Number (EIN)—is a nine-digit code the IRS assigns to most businesses. You can find it in several places depending on what documents you have access to and your relationship to the business.

If you are the business owner, check your IRS paperwork from when you first registered the business. The EIN appears on your SS-4 form (process for an Employer Identification Number), your first business tax return, and any IRS correspondence. If you are a customer, vendor, or employee looking up a business's EIN, the company's website often lists it in the "About Us" or legal footer section, or you can request it directly from the business.

For businesses you do not have a direct relationship with, the IRS provides a free public search tool and several other government databases can help you locate the number.

Key Takeaways

The IRS Business Tax ID Lookup tool at irs.gov lets you search by business name and state, and returns the EIN if the business is registered.
Your own business EIN appears on your SS-4 form, your tax returns, and any letter from the IRS addressed to your business.
Many businesses display their EIN on invoices, contracts, and their website's legal or footer section.
If a business refuses to provide its EIN when you request it directly, that is often a red flag for tax compliance problems.
State business registration databases and the Secretary of State's office can confirm a business's legal structure and sometimes list the EIN.

Using the IRS Business Tax ID Lookup Tool

The IRS offers a free online search at irs.gov/tax-professionals/tax-exempt-organization-search for tax-exempt organizations, and a separate tool for standard business EINs through their main website. Go to irs.gov, navigate to the "Tools" or "Search" section, and select the business lookup option.

Enter the business name exactly as it is registered with the IRS, and the state where it operates. The search returns the EIN if the business has filed tax documents with the IRS. This tool works best when you know the legal business name rather than a trade name or nickname the company uses in marketing.

If the search returns no results, the business may be too new (the IRS can take weeks to process a new EIN), may operate under a different legal name than you searched, or may not be registered with the IRS at all. Try searching again with variations of the business name, or contact the business directly.

Checking Your State's Business Registration Database

Every state maintains a business registration database, usually run by the Secretary of State's office. These databases list all registered corporations, LLCs, partnerships, and sole proprietorships in that state. Many include the EIN in the business record.

Visit your state's Secretary of State website and look for a link labeled "Business Search," "Entity Search," or "Corporate Records." Enter the business name and state. The search results show the business's legal structure, registration date, and often the EIN. Some states charge a small fee to view the full record; others provide it free.

This method works well when you know which state the business is registered in. If you are unsure, start with the state where the business operates or has its main office.

Asking the Business Directly

The simplest approach is often to ask. If you are a vendor, customer, or partner working with the business, send an email or call and request the EIN. Most legitimate businesses provide it without hesitation—they need to share it with contractors, banks, and insurance companies regularly.

Include a brief explanation of why you need it: "I need your EIN to complete a 1099 form" or "I need your EIN for our vendor records." Provide your own business information if you are requesting it for a formal reason, so the business knows the request is legitimate.

If a business refuses to provide its EIN or becomes evasive when asked, that is a warning sign. Legitimate businesses have no reason to hide this information. If you are considering a business relationship with them, that reluctance may indicate tax or legal problems.

Finding the EIN on Business Documents

If you have received paperwork from the business, the EIN often appears there. Check invoices, contracts, W-9 forms, and 1099 forms—all of these typically list the business's EIN. If you received a 1099 from the business, the EIN is in the top right corner of the form.

Loan documents, business licenses, and insurance policies also frequently display the EIN. If you are an employee, your W-2 form shows your employer's EIN in box b. If you are a contractor, any 1099-NEC or 1099-MISC you received lists the paying business's EIN.

This method requires you to have existing paperwork from the business, but it is often the fastest way to confirm the number if you do.

Using Third-Party Business Databases

Several private companies maintain searchable databases of business information, including EINs. Websites like Dun & Bradstreet, ZoomInfo, and Apollo offer free or low-cost searches. These databases pull information from public records, IRS filings, and business registrations.

Search by business name and location. Results usually include the EIN, business type, number of employees, and revenue estimates. Free versions may show limited information; paid subscriptions unlock more details. These tools are useful when the IRS lookup or state database does not return results, or when you want additional business information at the same time.

Be aware that third-party databases sometimes contain outdated or incomplete information, so confirm the EIN through an official source like the IRS or state database before relying on it for important transactions.

What to Do If You Cannot Find the EIN

If you have searched multiple sources and still cannot locate the EIN, the business may not have one. Sole proprietors who do not hire employees sometimes use their Social Security number instead of an EIN for tax purposes. In that case, ask the business owner directly whether they have an EIN or use their SSN.

If the business is very new, the EIN may not yet appear in public databases. The IRS can take two to four weeks to process a new EIN process and make it searchable. If the business was recently formed, wait a few weeks and search again.

For businesses operating outside the United States, the EIN system does not explore. Foreign businesses may have an ITIN (Individual Taxpayer Identification Number) or other tax identifier instead. If you are working with an international business, ask what tax ID they use in their home country.

Frequently Asked Questions

Can I find a business's EIN if I only know the owner's name?

Not reliably through the IRS lookup tool, which searches by business name and state. If you know the business name, use that instead. If you only have the owner's name, try searching your state's business database with the owner's name, or contact the business directly and ask for the EIN.

Is a business's EIN the same as its tax ID number?

For most businesses, yes. The EIN is the primary tax ID number the IRS uses. Sole proprietors without employees may use their Social Security number instead. Some businesses also have state tax ID numbers that differ from their federal EIN.

What if the EIN I found does not match the one on a document from the business?

Contact the business and ask which number is current. Businesses sometimes change their legal structure or re-register, which can result in a new EIN. The business should clarify which number is active and explain any discrepancy. If they cannot explain it, that is a red flag.

Do I need the business's EIN to file a 1099 form?

Yes. The IRS requires the contractor's or vendor's EIN (or SSN if they do not have an EIN) on all 1099 forms. If you cannot obtain the EIN after a good-faith effort to request it, the IRS allows you to file with the information you have, but the business may face penalties for not providing it.

Can I search for a business's EIN anonymously?

Yes. The IRS Business Tax ID Lookup tool and state business databases are public and do not require you to log in or provide your own information. You can search for any business's EIN without the business knowing you looked it up.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.