How to Find Your Business Tax ID Number

Where to Look for Your Business Tax ID

Your business tax ID number—officially called an Employer Identification Number (EIN)—is a nine-digit code the IRS assigns to your business. You can find it in several places without contacting the IRS, though the fastest route depends on when you received it and what documents you have on hand.

If you received your EIN by mail from the IRS, look for the official letter they sent you. This letter, titled "Notice of Action on Your process," contains your EIN in the upper right corner and is the document you'll reference most often. If you've misplaced the letter, your EIN also appears on your first business tax return, your business bank account paperwork, and any correspondence from the IRS about your account.

If you applied for your EIN online through the IRS website and printed your confirmation when ready, that confirmation page shows your number. Many business owners save this as a PDF or screenshot, so check your email attachments and downloads folder first.

Key Takeaways

Your EIN appears on the official IRS letter you received when the number was assigned, usually in the upper right corner of the page.
If you applied online and printed your confirmation, that page contains your EIN and is often easier to find than the original IRS letter.
Your business tax return, bank account statements, and any IRS notices also display your EIN if you need a backup source.
The IRS can look up your EIN by business name and address if you cannot locate it in your records, though this takes longer than checking your own documents.

Checking Your Business Bank and Loan Documents

Your business bank account paperwork is often the easiest place to find your EIN if you've opened an account since receiving the number. Banks require your EIN to set up a business account, so it appears on your account opening documents, monthly statements, and any loan or credit applications you've submitted.

Pull out your most recent bank statement or log into your online banking portal. Your EIN should appear near the top of the statement alongside your account number. If you've applied for a business loan or line of credit, the lender's paperwork will also show your EIN prominently, since they use it to verify your business identity and check your credit.

If you have a business credit card or merchant account for processing payments, those documents contain your EIN as well. Check any paperwork from PayPal, Square, or your payment processor if you use those services.

Finding Your EIN on Tax Documents and IRS Correspondence

Your business tax return is the official record of your EIN. If you filed a Form 1120 (corporate return), Form 1120-S (S-corporation return), Form 1065 (partnership return), or Schedule C (sole proprietor return), your EIN appears in the header section of the form. Pull up your copy of last year's return—either the paper copy you filed or a digital copy from your tax preparer or accounting software.

Any letter or notice from the IRS about your business account will display your EIN. This includes notices about tax payments due, correspondence about an audit, or letters confirming your business status. The IRS prints your EIN on nearly every piece of mail they send to a business, so even old notices are useful.

If you use accounting software like QuickBooks, FreshBooks, or Wave, your EIN is stored in your company settings. Log in and navigate to your company information or business details section—the exact location varies by software, but it's usually in settings or preferences.

Contacting the IRS to Look Up Your EIN

If you've checked all your documents and cannot find your EIN, the IRS can look it up for you. Call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have your business name, address, and the date you applied for the EIN ready when you call. The IRS typically answers business tax questions Monday through Friday, 7 a.m. to 7 p.m. your local time.

Be prepared to wait on hold, especially during tax season (January through April). The IRS can confirm your EIN over the phone and will provide it verbally, though they cannot mail you a replacement letter unless you request one separately. If you need an official copy of your EIN for a bank or government agency, ask the IRS representative how to request a formal letter of verification.

You can also mail a written request to the IRS, though this takes several weeks. Write to the IRS office that serves your state and include your business name, address, and the approximate date you applied for your EIN. The IRS website lists the mailing address for your region under "Where to File."

Using the IRS EIN Lookup Tool Online

The IRS does not offer a public online search tool where you can enter your business name and retrieve your EIN. However, if you applied for your EIN on or after November 2024, you may be able to look it up through the IRS online process system if you saved your confirmation page or have access to the email account you used to explore.

Some third-party websites claim to offer EIN lookup services, but these are not official IRS tools and may charge fees or collect unnecessary personal information. The safest approach is to check your own documents first, then contact the IRS directly if needed. Do not provide your Social Security number or business financial information to any website that is not the official IRS.gov domain.

What to Do If Your Business Never Received an EIN

If you cannot find your EIN because you never applied for one, you'll need to request one from the IRS. Sole proprietors without employees are not required to have an EIN—they can use their Social Security number on tax returns instead—but having an EIN keeps your personal and business finances separate and is necessary if you have employees, operate as a partnership or corporation, or want a business bank account.

You can explore for an EIN online at irs.gov/ein, by phone at 1-800-829-4933, by fax, or by mail. The online process is fastest and provides your EIN when ready upon approval. You'll need your business legal name, address, type of business structure, and the date you started or plan to start operations. The entire process takes about 15 minutes online.

Keeping Your EIN Safe and Organized

Once you locate your EIN, store it in a find place where you can find it quickly. Many business owners keep a copy of their original IRS letter in a fireproof safe or a password-protected digital folder. You'll need your EIN frequently—for tax returns, bank accounts, payroll setup, business licenses, and government contracts—so having it easily accessible saves time.

Do not share your EIN publicly or with anyone who doesn't have a legitimate business reason to request it. Treat it similarly to how you would treat your Social Security number. If you suspect someone has misused your EIN, contact the IRS when ready at 1-800-829-1040 to report identity theft.

Frequently Asked Questions

Can I get a new EIN if I've lost mine?

You don't need a new EIN—the number stays with your business for its lifetime. straightforward locate your existing number using the methods above. If you need an official letter confirming your EIN, the IRS can mail you a verification letter, but you'll use the same number you were originally assigned.

What if I have multiple businesses—do I need multiple EINs?

Each separate business entity needs its own EIN. If you operate two unrelated businesses as separate legal entities (two LLCs, for example), you'll have two different EINs. If you operate multiple locations under one business structure, you typically use one EIN for all locations, though some situations may require separate numbers. Contact the IRS to confirm your specific situation.

How long does it take the IRS to assign an EIN?

If you explore online, the IRS assigns your EIN when ready and you receive it on screen. If you explore by phone, you receive it verbally the same day. By mail or fax, assignment typically takes four weeks. Most businesses explore online because the when ready confirmation is useful for opening bank accounts and setting up payroll right away.

Do I need my EIN to file taxes as a sole proprietor?

No. Sole proprietors without employees can use their Social Security number on their tax return instead of an EIN. However, having an EIN is useful because it separates your personal and business finances, is required if you hire employees, and is necessary to open a business bank account.

What should I do if someone else is using my business EIN?

Contact the IRS when ready at 1-800-829-1040 to report the misuse. The IRS can investigate and take steps to protect your account. You may also want to file a report with the Federal Trade Commission at reportfraud.ftc.gov and contact your state's attorney general's office.

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.