Where to Find Your Business Tax ID Number

Your Business Tax ID is on your IRS paperwork or online account

Your Employer Identification Number (EIN) — also called your business tax ID — appears on the paperwork the IRS sent you when you first registered. If you registered online through IRS.gov, you can log into your account and retrieve it there. If you registered by mail and no longer have the original letter, the IRS website lets you look it up using your business name and address.

The EIN is a nine-digit number formatted as XX-XXXXXXX. You will need it to file business taxes, open a business bank account, hire employees, and explore for business licenses. If you cannot find it through the methods below, the IRS can confirm it by phone or mail, though phone confirmation requires you to verify your identity first.

Key Takeaways

Your EIN appears on the IRS letter you received when you first registered your business, usually titled "Notice of Approval" or "EIN Assignment Notice."
You can retrieve your EIN online through the IRS website by logging into your account or using the EIN lookup tool with your business name and address.
If you registered your business through a state agency or the SBA, they may have a record of your EIN that you can request.
The IRS can confirm your EIN by phone at 800-829-4933 if you can verify your business identity, though wait times are often long.

Check the IRS letter you received when you registered

When you first registered your business with the IRS — whether you filed Form SS-4 by mail, fax, or online — the agency sent you a confirmation letter. This letter contains your EIN and is usually titled "Notice of Approval" or "EIN Assignment Notice." The number appears near the top of the page and is formatted as XX-XXXXXXX.

Look through your business records, filing cabinets, and email for this letter. If you registered online, check your email inbox and spam folder for a message from the IRS. The letter typically arrived within two weeks of your registration. If you have moved or changed email addresses since registration, the letter may be in old files or with whoever managed your business setup.

Log into your IRS online account to retrieve it

If you registered your business online through IRS.gov, you can log into your account and view your EIN directly. Go to IRS.gov, select "Sign in" in the upper right, and choose the login method that matches how you registered — either with an IRS username and password, or through Login.gov if you created that account.

Once logged in, look for a section labeled "View Your EIN" or "Business Information." Your nine-digit EIN will be displayed there. If you do not remember your login credentials, the IRS website offers a password reset option. If you registered by mail or fax rather than online, you will not have an online account and should use the lookup tool instead.

Use the IRS EIN lookup tool on their website

The IRS provides a free lookup tool on IRS.gov that lets you find your EIN using your business name and address. Go to IRS.gov, search for "EIN lookup," and select the official IRS tool. Enter your business legal name exactly as it appears on your registration documents, your business address, and your state. The tool will return your EIN if the information matches what the IRS has on file.

This tool works whether you registered online, by mail, or by fax. It typically returns results within seconds. If the lookup does not find your EIN, double-check that you entered your business name and address exactly as they appear on your registration paperwork — even small differences like abbreviations or missing words can prevent a match.

Call the IRS to confirm your EIN by phone

If you cannot locate your EIN through the letter, online account, or lookup tool, you can call the IRS at 800-829-4933 and ask them to confirm it. Have your business name, address, and the date you registered ready. The IRS representative will ask you to verify your identity — usually by providing your Social Security Number or personal identification number — before they release the EIN.

Phone lines are often busy, especially during tax season, so expect to wait. Calling early in the morning or mid-week typically means shorter hold times. If you cannot reach the IRS by phone, you can also request your EIN by mail by sending a letter to the IRS address for your state, though this method takes several weeks.

Check with your state business agency or the SBA

If you registered your business through your state's Secretary of State office or through the Small Business Administration (SBA), those agencies may have a record of your EIN. Contact your state's business registration office and provide your business name and registration number. They can often confirm your EIN or direct you to where it is recorded.

Some states issue their own business identification numbers alongside the federal EIN, so make sure you are asking specifically for your federal EIN (the nine-digit number) rather than a state tax ID. The SBA does not issue EINs but can point you toward the correct IRS office if you registered through an SBA program.

Look for your EIN on past tax documents or bank records

If you have filed business taxes before, your EIN appears on your tax return — look at the top of Form 1040-SE, Form 1120, or whatever form you filed. If you have a business bank account, your EIN may also appear on bank statements, deposit slips, or account paperwork. Accountants and bookkeepers who have worked with your business may also have a copy of your EIN in their records.

Contact your bank, accountant, or anyone who has handled your business finances and ask them to provide your EIN from their records. This is often the fastest route if you have worked with a professional.

Frequently Asked Questions

What if I never received an EIN from the IRS?

If you registered your business but never received an EIN, the IRS may not have processed your registration. Use the EIN lookup tool on IRS.gov first — if it does not find a number, call 800-829-4933 to ask whether your registration was completed. You may need to re-register if the original process was lost.

Can I get a new EIN if I lost mine?

You do not need a new EIN. The number stays with your business for its lifetime. Instead, retrieve your existing EIN using the methods above. The only reason to request a new EIN is if your business structure changes — for example, if you convert from a sole proprietorship to an LLC.

Is my EIN the same as my business tax ID?

Yes, for federal purposes. Your EIN is your federal business tax ID. Some states also issue separate state tax ID numbers, which are different. Make sure you know which number you need — the federal EIN for IRS matters, and your state tax ID for state filings.

How long does it take to get an EIN if I do not have one yet?

If you register online through IRS.gov, you receive your EIN when ready. If you register by mail or fax, the IRS typically processes it within two weeks and sends you a confirmation letter. If you need the number before the letter arrives, you can call the IRS after two weeks to request it.

What do I do if the IRS lookup tool says my business does not exist?

This usually means your business name or address does not match what the IRS has on file. Try the lookup again with variations — abbreviations, full words instead of initials, or the address as it appears on your lease or registration. If it still does not work, call 800-829-4933 to verify that your registration was processed.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.