You can find your company’s EIN for free by checking a few documents you likely already have, and if none of them turn up, by calling the IRS to have the number confirmed at no cost. The nine-digit Employer Identification Number appears on almost every federal tax form and financial account the business has ever touched, so most owners locate it in minutes. When the paper trail runs cold, the IRS itself will read the number back over the phone and mail or fax a written replacement.
Start With the Original IRS Confirmation Letter
The fastest source is the notice the IRS mailed after approving your EIN application. That notice is designated CP 575, and the IRS issues it exactly once. It lists the nine-digit EIN, the legal business name, your tax classification, and your filing requirements. The letter itself warns you to keep it in your permanent records because the IRS will not generate a duplicate.1Internal Revenue Service. Employer Identification Number
Most owners file the CP 575 with their formation documents, so start with the folder that holds your articles of incorporation or organization, operating agreement, or bylaws. If you applied by phone or fax, the IRS instructions for Form SS-4 tell you to write the assigned number on the upper right corner of your completed application and keep that copy for your records.2Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025) That marked-up SS-4 is a solid backup if the CP 575 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 still shows the old information. The EIN itself does not change when you update your name or address, so the number on the notice is still valid.
Pull an Old Federal Tax Return
If the CP 575 is nowhere to be found, any federal tax return you have filed will show the EIN near the top of the first page.3Internal Revenue Service. Publication 583 (12/2024), Starting a Business and Keeping Records Which return to pull depends on how the business is set up:
- Corporations file Form 1120, or a variant like Form 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 their 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
If you have employees, check Form 941, the quarterly payroll tax return that reports withheld income tax, Social Security tax, and Medicare tax.7Internal Revenue Service. About Form 941, Employer’s Quarterly Federal Tax Return Form W-3, the annual summary you send to the Social Security Administration with your W-2s, carries the EIN as well.8Internal Revenue Service. Instructions for Form 941 – Section: How Should You Complete Form 941?
Any 1099 you filed for a contractor paid $600 or more will list your EIN, as will any W-9 you gave to a vendor before starting work together.9Internal Revenue Service. Information Returns (Forms 1099)
State filings are often faster than digging through years of federal returns. State corporate income tax returns, sales tax permits, and unemployment insurance filings typically require the federal EIN to link your state account to your federal records, so the most recent state form on your desk may be the quickest path.
Check Bank, Loan, and Licensing Paperwork
The EIN turns up in a surprising number of everyday business documents outside the tax folder. Your business bank required it to open the checking account, so the original account agreement and older statements are worth a look. The bank also uses your EIN when reporting interest income to the IRS, so it lives in their file even when it does not appear on the monthly statement itself.
Loan and credit paperwork is another reliable source. Lenders need the EIN to run commercial credit checks and report the debt, so any business loan, line of credit, or equipment lease application on file will include it.
Business licenses and operating permits issued by state or local agencies often print the EIN alongside the business name and address.10U.S. Small Business Administration. Get Federal and State Tax ID Numbers These tend to live in a desk drawer or filing cabinet rather than with the formal corporate records, so they are easy to overlook.
Call the IRS for a Free 147C Letter
When document searches come up empty, the IRS will confirm your EIN over the phone and send a written replacement at no charge. This replacement is called Letter 147C, and it stands in for the original CP 575 when banks, vendors, or state agencies ask for proof.1Internal Revenue Service. Employer Identification Number
Call the IRS Business and Specialty Tax Line at 800-829-4933, Monday through Friday, 7:00 a.m. to 7:00 p.m. your local time. Callers in Alaska or Hawaii should follow Pacific time.1Internal Revenue Service. Employer Identification Number After verifying your identity, the representative will read the EIN to you on the call and can mail or fax the 147C afterward.
Only an authorized person can request the number. For a corporation, that is a principal officer such as the president or vice president. For a sole proprietorship, it is the owner. For a partnership, it is 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 call on your behalf only if they have 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 this ready before you dial: the full legal name of the business, its current address, the entity type, and the name and title of the person who originally signed the EIN application. The IRS uses these details to match you to the account before releasing anything.
An entity transcript is a second free option through the same phone line or the IRS’s online business tax transcript tool. The transcript shows the EIN along with other account details like your filing requirements and tax classification, which can be useful if you need to verify more than the number itself.1Internal Revenue Service. Employer Identification Number
Finding Another Company’s EIN
If the EIN you need belongs to a business you do not own, the IRS will not release it over the phone, but there are free public routes for certain entity types.
Publicly traded companies must include their EIN on annual and quarterly filings with the SEC. Search the SEC’s EDGAR database, pull up the company’s 10-K or 10-Q, and the number appears on the cover page under “IRS Employer Identification Number.”12SEC.gov. EDGAR Full Text Search
For nonprofits, the IRS runs a free Tax Exempt Organization Search that lets you look up any 501(c)(3) or other exempt entity by name or EIN. The tool draws from Form 990 filings, determination letters, and the automatic revocation list.13Internal Revenue Service. Search for Tax Exempt Organizations
Private companies have no public filing that exposes the number. The simplest move is to ask the company directly and request a completed W-9. Any business you are paying for services should be willing to provide it, since you need the information to file your own 1099s.
When Finding the Old EIN Is Not Enough
Certain structural changes require a new EIN rather than a rediscovered one, so it is worth checking whether the number you are trying to recover still applies. As a general rule, changing the entity type triggers a new application; simply changing the business name or address does not.14Internal Revenue Service. When to Get a New EIN
- Sole proprietors need a new EIN if they incorporate, form a partnership, or file for bankruptcy.
- Corporations need a new EIN if they receive a new charter from the secretary of state, convert to a partnership or sole proprietorship, or merge to create a new corporation. Filing for bankruptcy alone does not require one.
- Partnerships need a new EIN if they incorporate, dissolve and start a new partnership, or if one partner takes over and operates as a sole proprietor. A partnership filing for bankruptcy keeps its existing EIN, and a change in ownership that does not terminate the partnership also keeps the same number.
- LLCs need a new EIN if they terminate and form a new corporation or partnership.
If you are buying an existing business, the seller’s EIN does not transfer to you. You will need to apply for your own.14Internal Revenue Service. When to Get a New EIN