To find the Taxpayer Identification Number for a business, start with who the business is. For your own company, the number is almost certainly your Employer Identification Number, and it lives on your IRS confirmation notice, prior tax returns, and business bank records. For another private business, you request it directly on Form W-9. For a public company, it’s in SEC filings. For a nonprofit, the IRS publishes it for free. Each path is covered below.
What Counts as a Business TIN
“TIN” is an umbrella term the IRS uses for several identifiers, and federal law requires one on tax documents.1Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers For a business, the TIN is almost always an Employer Identification Number, the nine-digit federal ID the IRS assigns to employers, corporations, partnerships, and most LLCs.2Internal Revenue Service. Employer Identification Number
Two exceptions are worth flagging before you start searching. A sole proprietor without employees can legally use a personal Social Security Number as the business tax ID, so a one-person operation may not have an EIN at all. And a business owner who isn’t eligible for an SSN may use an Individual Taxpayer Identification Number on personal returns, though a partnership or corporation they own would still need its own EIN. When someone asks for a “business TIN,” they almost always mean the EIN.
Finding Your Own Business EIN
If you’re the owner or an authorized officer trying to track down your own EIN, work through these sources in order. The number hasn’t gone anywhere; it’s on a document somewhere in your records.
The IRS Confirmation Notice
When the IRS first assigned your EIN, it issued a CP 575 notice. Online applicants received a digital copy to download and print; mail applicants received a single paper letter. The IRS does not reissue this notice, so if you saved it, that’s the fastest source.
Prior Federal Tax Returns
Your EIN appears on the first page of every federal return the business has filed. On a corporate Form 1120, it’s near the top with the entity name and address.3Internal Revenue Service. About Form 1120, U.S. Corporation Income Tax Return On a partnership Form 1065, it sits in Item D of the header.4Internal Revenue Service. 2025 Instructions for Form 1065 U.S. Return of Partnership Income Nonprofits filing Form 990 show it in Item D of the header as well.5Internal Revenue Service. 2025 Instructions for Form 990 Return of Organization Exempt From Income Tax If you don’t keep paper copies, your tax preparer or accounting software likely has the filings on hand.
Business Bank Records
Your bank collected the EIN when you opened the business account. Look at the account profile, monthly statements, or the original account opening paperwork. A call to the business banking line is usually the quickest route if none of that is at hand.
Calling the IRS
When no document surfaces, call the IRS Business and Specialty Tax Line at 800-829-4933, open Monday through Friday, 7:00 a.m. to 7:00 p.m. local time. An agent will verify your identity and give the EIN over the phone, but only to the business owner, an officer, or someone with proper authorization.2Internal Revenue Service. Employer Identification Number
Getting a TIN From Another Private Business
When you pay a vendor for services, rent, or other reportable transactions and need their TIN for a Form 1099, the standard approach is to ask them directly using Form W-9.
Form W-9 is the IRS form a U.S. person or entity uses to provide a TIN and certify tax classification. As the requester, you send a blank copy; the vendor fills in their name, entity type, and TIN, then signs and returns it.6Internal Revenue Service. About Form W-9, Request for Taxpayer Identification Number and Certification Always download the current version from IRS.gov; outdated versions cause problems. Collecting the W-9 at the start of the vendor relationship, rather than at year-end when 1099s are due, avoids scrambling.
Form W-9 is for U.S. persons and entities only. If the payee is a foreign business, request Form W-8BEN-E instead, which documents foreign status for withholding purposes.7Internal Revenue Service. About Form W-8 BEN-E, Certificate of Status of Beneficial Owner for United States Tax Withholding and Reporting (Entities)
Finding a Public Company’s EIN in SEC Filings
Publicly traded companies disclose their EIN in filings with the Securities and Exchange Commission. Those filings sit in EDGAR, the SEC’s free public database.8U.S. Securities and Exchange Commission. Accessing EDGAR Data
Search EDGAR by the company’s legal name and open the most recent Form 10-K (annual report) or Form 10-Q (quarterly report). The 10-K cover page has a dedicated line for the IRS Employer Identification Number, typically near the commission file number and the address of the principal executive offices.9Securities and Exchange Commission. Form 10-K – Annual Report Instructions This route works only for SEC filers, so it won’t help with a privately held company.
Finding a Nonprofit’s EIN
The IRS runs a free lookup tool for tax-exempt organizations. Tax Exempt Organization Search lets you find a nonprofit by name or location and pull its recent filings.10Internal Revenue Service. Tax Exempt Organization Search Once you locate the organization, open its most recent Form 990. The EIN is in Item D of the header on the first page.5Internal Revenue Service. 2025 Instructions for Form 990 Return of Organization Exempt From Income Tax This is the standard way to verify a charity’s tax-exempt standing before a deductible contribution or a grant agreement.
Verifying a TIN You Already Have
Having a number on file doesn’t help if it’s wrong. Incorrect TINs on information returns trigger IRS penalty notices and can force you into backup withholding. The IRS TIN Matching Program lets you check a name-and-TIN combination against IRS records before you file.
The program is open to payers who are registered on the IRS Payer Account File and who submit information returns.11Internal Revenue Service. Taxpayer Identification Number (TIN) Matching The Interactive TIN Matching tool accepts up to 25 name/TIN pairs at a time and returns results instantly, with a limit of 999 interactive requests per user in a 24-hour period. A result code of “0” means the name and TIN match IRS records. A “3” means they don’t, and you’ll need to go back to the vendor for corrected information. Bulk TIN Matching handles higher volumes for larger operations.
A Note on State Tax ID Numbers
A federal EIN doesn’t cover state tax obligations. Most states issue their own tax identification numbers, and a single business may end up with separate IDs for sales tax, employee income tax withholding, and unemployment insurance. Formats and registration processes vary by state, so you’ll need to check with the state’s department of revenue or tax authority for the specific numbers that apply to your business.12U.S. Small Business Administration. Get Federal and State Tax ID Numbers If you’re trying to look up a state ID for another business, the federal sources above generally won’t have it.