You can find your company’s EIN for free by checking the IRS confirmation letter you received when the number was issued, pulling it off any federal tax return the business has filed, or looking at the paperwork your bank or lender keeps on file. If none of those turn it up, the IRS will verify the number over the phone at no charge and mail or fax a replacement confirmation. Work through the sources below in roughly that order, from the fastest to the most involved.
Start With the Original IRS Confirmation Letter
When the IRS approved your EIN application, it sent a one-page notice called CP 575. That notice shows the nine-digit EIN along with the legal business name, your tax classification, and your filing requirements. The IRS issues CP 575 exactly once and warns on the notice itself to keep it in your permanent records, because it will not generate a duplicate.1Internal Revenue Service. Employer Identification Number
Most owners file CP 575 with their formation documents, so check wherever you keep your articles of incorporation or organization, your operating agreement, or your bylaws. If you applied by phone or fax, the IRS instructions for Form SS-4 direct applicants to write the assigned number on the upper right corner of the completed application and keep that copy.2Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025) That handwritten copy is a solid backup if the original notice has gone missing.
One caveat. The CP 575 reflects the business name and address at the time you applied. If the company has since changed names or moved, the letter will show the old information. The EIN itself does not change when you update your name or address, so the number on the notice is still the right one.
Pull the EIN Off a Federal Tax Return
If the CP 575 is gone, any federal return the business has filed will carry the EIN near the top of the first page.3Internal Revenue Service. Publication 583 (12/2024), Starting a Business and Keeping Records Which return depends on how the business is organized:
- Corporations file Form 1120, or a variant like 1120-S for S corporations.4Internal Revenue Service. About Form 1120, U.S. Corporation Income Tax Return
- Partnerships and multi-member LLCs file Form 1065.5Internal Revenue Service. About Form 1065, U.S. Return of Partnership Income
- Single-member LLCs are generally disregarded for federal tax purposes, and the owner reports income on a personal return. These businesses sometimes use the owner’s Social Security Number rather than an EIN on Schedule C.6Internal Revenue Service. Instructions for Form 1120 (2025) – General Instructions
Businesses with employees have more places to look. Form 941, the quarterly payroll tax return that reports withheld income tax, Social Security tax, and Medicare tax, carries the EIN.7Internal Revenue Service. About Form 941, Employer’s Quarterly Federal Tax Return So does the annual Form W-3 that transmits W-2 data to the Social Security Administration.8Internal Revenue Service. Instructions for Form 941 – Section: How Should You Complete Form 941?
If you paid independent contractors $600 or more in a year, the 1099 forms you filed for those payments show your EIN, as do any W-9 forms you exchanged with vendors.9Internal Revenue Service. Information Returns (Forms 1099)
Don’t overlook state filings. State corporate income tax returns, sales tax permits, and unemployment insurance filings typically require the federal EIN to link the state account to federal records. The most recent state filing is often faster to grab than a years-old federal return.
Check Bank, Loan, and Licensing Paperwork
The EIN turns up in a lot of ordinary business records. The bank that holds your business checking account required the number to open it, so it will be on the original account agreement and in the bank’s files, even if it does not print on your monthly statements. The bank also uses the EIN when it reports interest income to the IRS.
Loan applications and credit agreements are another dependable source. Lenders need the EIN to run commercial credit checks and report the debt, so any business loan, line of credit, or equipment lease paperwork should include it.
State and local business licenses and operating permits often list the EIN next to the business name and address.10U.S. Small Business Administration. Get Federal and State Tax ID Numbers These tend to sit in a desk drawer or filing cabinet rather than with the formal corporate records, so they’re easy to miss on a first pass.
Call the IRS for Letter 147C
When nothing in your files produces the number, the IRS offers two free options: a replacement confirmation known as Letter 147C, or an entity transcript showing your business tax account details.1Internal Revenue Service. Employer Identification Number
Call the Business and Specialty Tax Line at 800-829-4933, Monday through Friday, 7:00 a.m. to 7:00 p.m. local time. Callers in Alaska and Hawaii follow Pacific time.1Internal Revenue Service. Employer Identification Number After verifying your identity, the representative will read the EIN to you and can send Letter 147C by mail or fax. The letter works as written proof of the EIN for banks, vendors, and anyone else who asks for documentation.
Only authorized people can request the number. For a corporation, that’s a principal officer such as the president or vice president. For a sole proprietorship, it’s the owner. For a partnership, it’s a member or officer with knowledge of the business’s affairs.2Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025) A third party can also call if they’ve been designated on Form 2848 (Power of Attorney) or Form 8821 (Tax Information Authorization).11Internal Revenue Service. Instructions for Form 2848 (Rev. September 2021) – Section: Purpose of Form
Have the following ready before you dial:
- The full legal name of the business
- The current address
- The entity type
- The name and title of the person who originally signed the EIN application
The IRS uses this information to match you to the account before releasing anything. An entity transcript is available through the same phone line or the IRS’s online business tax transcript tool, and it’s useful if you also want to confirm filing requirements or tax classification along with the EIN.1Internal Revenue Service. Employer Identification Number
If You Suspect You Have Two EINs
Businesses sometimes end up with duplicate EINs, usually because a second application went through without anyone realizing the first one had been approved. The same Business and Specialty Tax Line at 800-829-4933 will tell you which EIN is tied to your active account.1Internal Revenue Service. Employer Identification Number Filing a return under the wrong number can trigger mismatches with the IRS and the Social Security Administration, so it’s worth clearing up before the next deadline.
Looking Up Another Company’s EIN
The IRS will not give out another business’s EIN over the phone, but public routes exist depending on the entity type.
Publicly Traded Companies
The Securities and Exchange Commission requires public companies to include their EIN in annual and quarterly filings. Search the SEC’s EDGAR database at sec.gov/edgar by company name or ticker, open a 10-K or 10-Q, and look on the cover page under “IRS Employer Identification Number.”12SEC.gov. EDGAR Full Text Search
Nonprofits
The IRS runs a free Tax Exempt Organization Search tool that lets you look up a 501(c)(3) or other tax-exempt entity by name or EIN. It pulls from Form 990 filings, determination letters, and the automatic revocation list.13Internal Revenue Service. Search for Tax Exempt Organizations Because nonprofits must file publicly available Form 990 returns, their EINs are effectively public.
Private Companies
Private companies have no public filing requirement that exposes the EIN. The simplest path is to ask the company directly for a completed W-9. Any vendor you’re paying for services should be willing to provide one, since you need the information to issue a 1099.