To find a business tax ID number, start with the paperwork the business already has: the IRS confirmation notice, prior federal tax returns, bank account applications, and any 1099 forms tied to the business. If those come up empty and it’s your own company, the IRS Business and Specialty Tax Line at 800-829-4933 will confirm the nine-digit Employer Identification Number over the phone once it verifies your identity. If you’re trying to find another organization’s EIN, the path depends on what kind of entity it is: public companies disclose it in SEC filings, nonprofits publish it through IRS databases and Form 990, and private companies generally don’t expose it anywhere public.
Check Your Own Records First
The single best document is the CP 575 notice the IRS mailed when it first assigned the EIN. It’s a one-page confirmation, and most owners tuck it away with their formation paperwork. If you applied online, a PDF version may still be sitting in your files from the application session.
If the CP 575 is gone, ask the IRS for a 147C letter. It’s a replacement verification that banks, payroll providers, and government agencies accept as proof of the number. You have to call for it — the IRS doesn’t issue 147C letters online — at 800-829-4933.
Prior federal tax returns are the next place to look. Corporations will find the EIN in the header of Form 1120. Partnerships and multi-member LLCs will find it in the same spot on Form 1065.1Internal Revenue Service. Instructions for Form 1120 (2025) A sole proprietor who used an EIN will find it on the Schedule C attached to Form 1040. In each case the number sits near the top of the first page next to the business name and address.
Bank Documents, 1099s, and Licenses
Banks collect the EIN whenever you open a business checking account or apply for a credit line, so log into your online banking portal or pull up the original account application.2Chase for Business. What Do You Need to Open a Business Bank Account? Many banks display the number on an account profile or summary page.
If your business paid independent contractors, any Form 1099-NEC you issued shows your EIN in the “Payer’s TIN” field near the top.3Internal Revenue Service. Form 1099-NEC (Rev. April 2025) The reverse also works: if another company paid your business as a contractor, the 1099-NEC they sent you carries your number in the “Recipient’s TIN” field. Quarterly payroll tax filings held by your payroll provider will also have it.4LII / Legal Information Institute. Employer Identification Number (EIN)
Business licenses, building permits, and state registration filings usually asked for the EIN at the time of application. Even if you can’t dig up the originals, the issuing agency can often pull the file.
Calling the IRS
When the paper trail runs dry, the IRS will read the number to you over the phone. The Business and Specialty Tax Line is 800-829-4933, open Monday through Friday from 7:00 a.m. to 7:00 p.m. in your local time zone (Alaska and Hawaii follow Pacific time).5Internal Revenue Service. Telephone Assistance Contacts for Business Customers Mornings and tax season mean longer holds.
The IRS will only release the number to the “responsible party” listed on the original application. Who that is depends on the entity type:6Internal Revenue Service. Responsible Parties and Nominees
- Corporation: the principal officer
- Partnership: a general partner
- Sole proprietorship: the owner
- Trust: the grantor or trustor
- Estate: the executor or personal representative
- Tax-exempt organization: the principal officer
The agent will ask for identifying information such as your Social Security number and the business address on file.7Internal Revenue Service. Employer Identification Number Once you’re verified, they’ll read the EIN back to you and can mail a 147C letter if you need one on paper.
Finding a Public Company’s EIN
Publicly traded companies have to disclose their EIN in their SEC filings, and the SEC’s EDGAR database is free.8U.S. Securities and Exchange Commission. About EDGAR Search by the company’s legal name and open the annual report (Form 10-K) or a quarterly report (Form 10-Q). On the 10-K, the EIN appears on the cover page under a field labeled “(I.R.S. Employer Identification No.)” directly beneath the company name and state of incorporation.9SEC.gov. Form 10-K – Annual Report Form and Instructions Anyone can pull it up; no permission needed.
Finding a Nonprofit’s EIN
Tax-exempt organizations put their EINs into the public record through the IRS. The Tax Exempt Organization Search tool lets you look up any 501(c)(3) or other exempt entity by name or EIN, and it draws from Pub. 78 (organizations eligible to receive tax-deductible contributions), the auto-revocation list, and Form 990 returns.10Internal Revenue Service. Search for Tax Exempt Organizations One catch: Pub. 78 only lists the organization’s official name as submitted to the IRS, so a “doing business as” name won’t return anything.
If you’re reading an actual Form 990, the EIN is in Item D of the heading section on page 1.11Internal Revenue Service. Instructions for Form 990 Return of Organization Exempt From Income Tax (2025)
Finding a Private Company’s EIN
This is the hard case. The IRS does not run a public lookup tool for private-business EINs. Unlike public companies and nonprofits, a privately held company’s number is generally not accessible through any government database.
Your realistic options are narrow. Ask the business directly — companies routinely share their EIN with vendors, contractors, and partners for tax reporting. If the company paid you as a contractor, the 1099-NEC it sent you already has the number. Beyond that, commercial credit services like Dun & Bradstreet use EINs as identifiers in their business credit files, but access typically requires a paid subscription and often the business’s cooperation. There is no free federal lookup for a private company’s EIN.
When You Need a New EIN Instead
Sometimes what you actually need isn’t the old number but a new one. Changing your business name or moving to a new address does not trigger a new EIN.12Internal Revenue Service. When to Get a New EIN Structural changes do, and the triggers depend on entity type:
- Sole proprietors need a new EIN when incorporating, forming a partnership, or declaring bankruptcy.
- Corporations need one when receiving a new charter from the secretary of state, converting to a partnership or sole proprietorship, or merging to create a new corporation. A corporation that survives a merger keeps its existing EIN.
- Partnerships need a new EIN when incorporating, when a single partner takes over as a sole proprietor, or when ending and starting a new partnership. Ownership changes that don’t terminate the partnership don’t require a new number.
- LLCs need a new EIN when terminating and forming a new corporation or partnership, or when a single-member LLC has to start filing employment or excise taxes.
If you do need a new one, the IRS online application is the fastest route and issues the number immediately on approval. You can only get one EIN per responsible party per day.13Internal Revenue Service. Get an Employer Identification Number
Signs Someone Else Is Using Your EIN
An EIN can be stolen and used to file fraudulent returns or fake W-2s. Watch for these signs:14Internal Revenue Service. Identity Theft Information for Businesses
- Your e-filed return is rejected because one with the same EIN was already submitted.
- You receive a tax transcript or IRS notice that doesn’t match anything you filed.
- Routine IRS correspondence stops arriving because someone changed the business address on file.
- You get IRS Letter 6042C or 5263C, which can signal identity issues.
If any of that happens, file Form 14039-B, the Business Identity Theft Affidavit, right away.15Internal Revenue Service. Report Identity Theft for a Business The form covers businesses, trusts, estates, and tax-exempt organizations. Include the requested supporting documents and sign it to avoid processing delays. If you had a data breach but no tax-related fallout, Form 14039-B is not the right step.