Your business tax ID is on documents you already have or can request in minutes

Your Employer Identification Number (EIN) appears on your business tax returns, bank statements, and payroll records. If you cannot find it in those places, the IRS will look it up for you by phone or mail using your business name and formation date. You do not need to re-explore or pay a fee — the number was assigned when you registered your business, and the IRS has it on file.

The fastest route is to call the IRS Business and Specialty Tax Line at 1-800-829-4933, Monday through Friday, 7 a.m. to 7 p.m. your local time. Have your business name, formation date, and Social Security number or prior EIN ready. They will give you the number over the phone and can mail you a printed copy if you need it for a lender or vendor.

Key Takeaways

  • Your EIN is printed on your most recent business tax return (Form 1120, 1120-S, 1065, or 1040-C), payroll tax forms, and bank statements — check those first before calling the IRS.
  • The IRS can look up your EIN by phone at 1-800-829-4933 if you have your business name, formation date, and Social Security number.
  • If you formed your business through your state (LLC, corporation, or partnership), your state's business filing office also has a record and can confirm the number.
  • A printed EIN confirmation letter from the IRS takes 2 to 4 weeks by mail but can be requested by phone and is often accepted by banks and vendors as proof.

Check your existing business documents first

Your EIN is printed on every tax document your business has filed. If you have filed a federal business tax return, look at the top of Form 1120 (C corporation), Form 1120-S (S corporation), Form 1065 (partnership), or Schedule C on your Form 1040 (sole proprietor). The EIN is a nine-digit number formatted as XX-XXXXXXX.

If you run payroll, your EIN appears on every payroll tax return you file — Form 941 (quarterly), Form 940 (annual), or Form 943 (agricultural). Your payroll processor or accountant can also pull it from your account in seconds.

Bank statements also list your EIN if the account is registered under your business name. Check your most recent statement or log into your online banking portal and look at the account details page.

Call the IRS to retrieve your number

The IRS Business and Specialty Tax Line will look up your EIN over the phone at no cost. Call 1-800-829-4933 Monday through Friday, 7 a.m. to 7 p.m. your local time. Have ready: your business name (exactly as it appears on your tax return), the date you formed the business, and your Social Security number or the prior EIN if you have one.

The agent will confirm the EIN and can answer basic questions about whether the number is active. If you need a written confirmation letter, you can request one by phone, and the IRS will mail it to the address on file. The letter typically arrives in 2 to 4 weeks and serves as official proof for banks, vendors, and government agencies.

If you cannot reach the IRS by phone during business hours, you can also submit Form SS-4 by mail to request a new EIN or retrieve an existing one, though this takes 4 to 6 weeks.

Check your state business filing office

Your state's Secretary of State office or business filing department has a record of your EIN if you registered your business as an LLC, corporation, or partnership. Most states allow you to search their business database online for free using your business name.

Go to your state's Secretary of State website and look for "business search" or "entity search." Type your business name and you will see the formation date, current status, and often the EIN. If the search tool does not display the EIN, you can call the office directly — the number is on the website — and they will read it to you.

This route is useful if you formed your business recently and have not yet filed a federal tax return, or if you need to confirm the exact legal name your business was registered under.

Request a printed EIN letter from the IRS

Banks, lenders, and vendors sometimes ask for written proof of your EIN. The IRS issues a free EIN Confirmation Letter that serves as official documentation. You can request one by calling 1-800-829-4933 and asking the agent to mail it to you, or by submitting Form SS-4 by mail.

The letter includes your business name, EIN, formation date, and business structure. It arrives in 2 to 4 weeks. Some vendors will also accept a copy of your most recent tax return as proof instead of waiting for the letter.

If you need the letter urgently, ask the IRS agent if they can email or fax it to you — some offices will do this if you provide a fax number or email address, though this is not may provide.

What to do if you cannot find your EIN anywhere

If you have filed a tax return but cannot locate your EIN and the IRS cannot find it in their system, your business may have been assigned a number that was never activated or recorded correctly. This sometimes happens if you filed a return before your EIN was fully processed.

Call the IRS at 1-800-829-4933 with your business name and formation date. If the agent confirms no EIN exists, you will need to explore for a new one. You can do this by phone (the agent can assign one when ready) or by mailing Form SS-4. The new number will be active right away.

If you are a sole proprietor who has never filed a business tax return and do not have an EIN, you can use your Social Security number instead. You only need an EIN if you have employees, operate as a partnership or corporation, or choose to keep your business finances separate from your personal taxes.

Frequently Asked Questions

Can I look up someone else's business EIN?

Yes, if the business is registered with your state. Search your state's Secretary of State database using the business name. Federal tax returns are confidential, so the IRS will not release an EIN to anyone but the business owner or an authorized representative with power of attorney.

What if my business has multiple locations or divisions?

Each legal entity (separate LLC, corporation, or partnership) has its own EIN. If you operate under one legal structure with multiple locations, you have one EIN. If you created separate entities for different divisions, each one has a different number. Check your formation documents to see how many legal entities you created.

Do I need an EIN if I am a sole proprietor with no employees?

No. Sole proprietors without employees can use their Social Security number on tax returns. You only need an EIN if you hire employees, form a partnership or corporation, operate as an S corporation, or want to keep business finances separate from personal ones.

How long does it take to get a new EIN if mine was lost or never issued?

If you call the IRS, a new EIN is assigned when ready and is active right away. If you mail Form SS-4, it takes 4 to 6 weeks. The phone route is faster and costs nothing.

What if the IRS says my business name does not match their records?

Businesses often file taxes under a slightly different name than they registered with the state (a "doing business as" or DBA). Tell the IRS agent the exact name on your most recent tax return. If that does not work, provide the legal name your business was registered under with the state, and the agent can search both.