To find a business tax ID number, start with the paperwork the IRS and the business itself already generate: the original EIN confirmation notice, past federal tax returns, business bank records, and payroll or 1099 forms. If those come up empty, the IRS will give the number to an authorized person over the phone or through a business tax transcript. If you’re trying to find someone else’s EIN, the method depends on whether the company is public, tax-exempt, or private.
Look in Your Own Records First
The quickest source is the CP 575 notice the IRS sent when the EIN was first issued. It lists the number, your business’s legal name, the filing address on record, and the federal forms you’re required to file. Online applicants had the option to print it immediately; paper copies arrive within a few weeks of approval.
If the CP 575 is gone, pull a previously filed federal return. Corporations will see the EIN near the top of Form 1120, and partnerships will find it on Form 1065.1Internal Revenue Service. Instructions for Form 1120 A sole proprietor who obtained an EIN can check the Schedule C attached to Form 1040.
Your bank has it too. Federal law requires an EIN to open a commercial account, so the number is on the original account application and usually visible inside the business banking portal under your profile.2Internal Revenue Service. Employer Identification Number Beyond that, any 1099-NEC you’ve issued, W-2s you’ve filed, and loan or credit applications will show the number.
Get Your EIN From the IRS
When nothing in your own records surfaces it, the IRS offers two direct paths.
Call the Business and Specialty Tax Line
The IRS Business and Specialty Tax Line is 800-829-4933, open Monday through Friday, 7 a.m. to 7 p.m. local time (Alaska and Hawaii use Pacific time).3Internal Revenue Service. Telephone Assistance Contacts for Business Customers The agent will verify your identity against the IRS Master File, checking the entity’s legal name, the responsible party from the original application, and the mailing address on record.
Only someone authorized to act for the business can receive the EIN by phone: a corporate officer, a general partner, a sole proprietor, or someone with a valid Power of Attorney on Form 2848. If verification fails, the agent will deny the request. Once you clear it, you get the number on the call. Written confirmation may follow by mail several weeks later.
Request a Business Tax Transcript
A business tax transcript is an IRS-generated document that shows filing history and includes the EIN. You can view, print, or download one through the IRS business tax account online, request it by mail using Form 4506-T, or ask for one through the same 800-829-4933 line.4Internal Revenue Service. Get a Business Tax Transcript The online option is fastest if the business already has IRS online account access set up.
What to Have in Front of You
Any IRS search moves faster with the entity’s exact legal name from its formation documents, which is often different from a trade name or DBA. You’ll also want the responsible party from the original application, the mailing address used at registration, and the entity type (LLC, corporation, partnership, and so on). On a phone call, these must match the Master File. Relying on memory for the old address is a common reason calls fail, so check old correspondence or formation paperwork before you dial.
Finding Another Business’s EIN
Needing another company’s EIN comes up constantly, especially when preparing 1099s or verifying a vendor. The right method depends on what kind of entity it is.
Ask With a Form W-9
The simplest approach, and the one the IRS expects for most business-to-business situations, is to send the other company a Form W-9 and ask them to complete it. That form exists for exactly this purpose: the business provides its legal name, entity type, and taxpayer identification number so the requester can prepare accurate information returns. A business that refuses to furnish its TIN faces a $50 penalty per failure, and any payments you make to them become subject to backup withholding.5Internal Revenue Service. Form W-9 Request for Taxpayer Identification Number and Certification Legitimate businesses rarely refuse.
Public Companies: Search SEC EDGAR
Every publicly traded company files an annual Form 10-K with the Securities and Exchange Commission, and the cover page includes the EIN.6SEC.gov. Form 10-K Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 The EDGAR Full-Text Search tool at sec.gov/edgar/search is free. Search by company name or ticker, open the most recent 10-K, and the EIN appears near the top with the company’s address and state of incorporation.7U.S. Securities and Exchange Commission. Form 10-K
Nonprofits: Use the IRS Tax Exempt Organization Search
Most tax-exempt organizations file Form 990 each year, and the EIN is on the return.8Internal Revenue Service. Instructions for Form 990 Return of Organization Exempt From Income Tax The IRS makes these filings searchable for free through Tax Exempt Organization Search at apps.irs.gov/app/eos. Look up the organization by name and open its return.9Internal Revenue Service. Tax Exempt Organization Search The same database shows whether the group’s tax-exempt status is currently active or has been revoked, which is useful for donor due diligence.
Private Companies
Private businesses have no obligation to publish their EIN, and no free government database will produce it. The W-9 is still your best route. Commercial credit reporting services keep business records that sometimes include identifying details, but those are paid products built for credit evaluation, not EIN lookup. If a private company won’t provide its EIN on a W-9 and you need it for information reporting, document every request. The IRS may waive penalties if you can show a good-faith effort to obtain the number.
An Old EIN Hasn’t Disappeared
One thing worth knowing before you go looking: once the IRS assigns an EIN, it becomes the entity’s permanent federal taxpayer ID. Even after the business closes, the IRS cannot cancel it, and it will never be reassigned to another entity.10Internal Revenue Service. If You No Longer Need Your EIN A past EIN can always be retrieved through IRS records, even if the business shut down years ago.
Skip the Paid Lookup Sites
A cottage industry of websites charges anywhere from $50 to $300 to “obtain” or “look up” an EIN, often designed to look like government pages. In April 2025, the Federal Trade Commission sent warning letters to operators of these sites, noting that some of their practices may violate the FTC Act and federal impersonation rules by suggesting affiliation with the IRS.11Federal Trade Commission. FTC Warns Operators of Websites That Charge for Employer Identification Number The IRS issues EINs for free, and every recovery method above, from the phone line to EDGAR to the Tax Exempt Organization Search, costs nothing. If a site is asking for a credit card before it will show you an EIN, close the tab.