You can look up an EIN for free in a few different ways, and which one works depends on whose number you need. For your own business, start with your paperwork — the IRS assignment notice, a prior tax return, a W-2 you issued, or a bank document — and if none of those turn up the number, call the IRS Business and Specialty Tax Line at 800-829-4933 to have it read back or faxed to you. For another entity’s EIN, the free routes are asking the business for a Form W-9, pulling a publicly traded company’s most recent SEC filing, or searching the IRS Tax Exempt Organization Search for a nonprofit.
Find Your Own EIN in Records You Already Have
The IRS itself recommends checking your own files before contacting the agency, and in most cases the number turns up within a few minutes.1Internal Revenue Service. Employer Identification Number – Section: Lost or Forgot EIN
The CP 575 Assignment Notice
When the IRS approved your Form SS-4 application, it issued a CP 575 Notice with the EIN printed near the top. If you applied online, the notice could be viewed, printed, and saved at the end of the session, so check downloads folders and email archives. Fax applicants received the number back within about four business days; mail applicants received the notice roughly four weeks later.2Internal Revenue Service. Instructions for Form SS-4 (12/2025) – Section: How To Apply for an EIN
Prior Tax Returns and Payroll Forms
Your EIN prints on the first page of every federal business return you’ve filed. That includes Form 1120 for corporations, Form 1065 for partnerships, Form 941 for quarterly payroll, and Form 940 for annual unemployment tax.3Internal Revenue Service. Instructions for Form 941 (Rev. March 2026) If you e-file, your tax software stores the return and the EIN is searchable inside the account.
W-2s, 1099s, and Bank Documents
W-2 forms you issued to employees show the EIN in Box B.4Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026) – Section: Specific Instructions for Form W-2 Forms 1099 sent to contractors carry it in the payer’s identification box. Even if you no longer have copies, a former employee or contractor may.
Banks collect the EIN when you open a business account as part of their customer identification requirements, so the original account application or a recent statement may show it.5FFIEC BSA/AML Manual. Assessing Compliance with BSA Regulatory Requirements – Customer Identification Program If it doesn’t, the bank can look it up for you.
Old IRS Letters
Any correspondence the IRS sent about your business — audit notices, payment confirmations, address change acknowledgments — uses the EIN as the account reference number. It’s worth a look through your correspondence file before making a phone call.
Get Your EIN from the IRS Directly
If your records search comes up empty, the IRS is the definitive source. There is no free online tool that will hand you an existing EIN — retrieval requires either a written request or a live phone call, for security reasons.
Call the Business and Specialty Tax Line
Dial 800-829-4933, Monday through Friday, 7:00 a.m. to 7:00 p.m. your local time. Alaska and Hawaii callers follow Pacific time.6Internal Revenue Service. Telephone Assistance Contacts for Business Customers – Section: Business and Specialty Tax Line and EIN Assignment (800-829-4933) Ask the representative for Letter 147C, which is a replacement confirmation of your previously assigned EIN. The letter can be faxed to you during the call, so you leave with a written record rather than only a spoken number.7Internal Revenue Service. Employer Identification Number – Section: EIN Confirmation
Who the IRS Will Talk To
The IRS will only release the EIN to the responsible party listed on the original Form SS-4. A responsible party is the actual person who owns, controls, or manages the entity and its funds — not another business.8Internal Revenue Service. Responsible Parties and Nominees By entity type, that’s:
- Corporation: the principal officer
- Partnership: a general partner
- Tax-exempt organization: the principal officer
- Trust: the grantor or trustor
- Estate: the executor or personal representative
- Sole proprietorship: the owner
What to Have Ready
The representative will cross-reference what you say against the original Form SS-4 filing. Have the business’s legal name, mailing address, and entity type on hand, plus the name and Social Security Number or ITIN of the responsible party. If any detail doesn’t match IRS records exactly, the agent cannot release the number and will refer you to the person who filed the original application. Federal law (Internal Revenue Code Section 6103) prohibits IRS employees from disclosing tax information to anyone who can’t verify authority to receive it.9Office of the Law Revision Counsel. 26 USC 6103 – Confidentiality and Disclosure of Returns and Return Information
Having a CPA or Attorney Call for You
If you want a representative to handle the call, file Form 2848 (Power of Attorney and Declaration of Representative) to authorize them to act on your behalf, or Form 8821 (Tax Information Authorization) if you only need them to receive or inspect information.10Internal Revenue Service. Instructions for Form 2848 (Rev. September 2021)11Internal Revenue Service. About Form 8821, Tax Information Authorization The form has to be on file with the IRS before the representative calls.
Written Alternative: The Entity Transcript
The IRS also offers an Entity transcript through its online transcript system. The transcript is a summary of your business account information and includes the EIN, giving you a written confirmation without needing to place a call.
Look Up Another Business’s EIN for Free
There is no free public database of private-business EINs. The IRS won’t release someone else’s number on request, and paid commercial lookup services exist precisely because a general free search doesn’t. That said, several legitimate free routes cover most situations.
Ask for a Form W-9
The most common approach is to ask the business directly. Form W-9 (Request for Taxpayer Identification Number and Certification) is the standard document for collecting an EIN or SSN from a payee.12Internal Revenue Service. About Form W-9, Request for Taxpayer Identification Number and Certification For the 2026 tax year, you’re required to file an information return such as a 1099-NEC when you pay a U.S.-based business or individual $2,000 or more in the calendar year, up from the longstanding $600 amount for tax years beginning after 2025.13Internal Revenue Service. 2026 Publication 1099 Most vendors return a completed W-9 quickly because they expect the request.
Publicly Traded Companies: SEC EDGAR
Public corporations disclose their EIN in filings with the Securities and Exchange Commission. Annual reports (Form 10-K) and quarterly reports (Form 10-Q) list the federal tax identification number on the cover page.14SEC.gov. EDGAR Company Search Search EDGAR by company name or ticker, open the most recent 10-K, and the EIN sits on the first or second page alongside the state of incorporation and address.
Nonprofits: IRS Tax Exempt Organization Search
Tax-exempt organizations file Form 990 as their annual information return, and Form 990 is a public document with the EIN printed on the first page.15Internal Revenue Service. About Form 990, Return of Organization Exempt from Income Tax The IRS runs a free Tax Exempt Organization Search where you can look up any exempt organization by name or EIN and pull copies of filed returns.16Internal Revenue Service. Tax Exempt Organization Search Smaller nonprofits with gross receipts normally under $50,000 may file only the electronic notice (Form 990-N), but their EIN still appears in the search results.17Internal Revenue Service. Exempt Organization Annual Filing Requirements Overview
State Licensing Databases
Some state regulators in fields like insurance, banking, and healthcare publish the federal EIN alongside state license information. Availability is inconsistent by state and industry, but it’s worth a quick check of the relevant agency’s website when the other free routes don’t fit.
Keep Your Records Current So Retrieval Still Works
An EIN is permanent, but the information attached to it is not. If the business changes its mailing address, physical location, or responsible party, you must notify the IRS within 60 days using Form 8822-B.18Internal Revenue Service. About Form 8822-B, Change of Address or Responsible Party – Business There’s no penalty for filing late, but an outdated file has real costs: the IRS may send notices of deficiencies and payment demands to an address you no longer read, and interest keeps accruing whether you saw the notice or not.19Internal Revenue Service. Form 8822-B Change of Address or Responsible Party – Business An outdated responsible party also creates a retrieval problem down the road. If the person listed on the original SS-4 is no longer with the company, nobody currently on staff can pass the identity check to get the EIN back by phone.