Where to find a business tax ID

A business tax ID — also called an Employer Identification Number or EIN — is a nine-digit number the IRS assigns to identify your business for tax purposes. You can find it on your IRS documentation, your business bank account paperwork, or by searching the IRS website directly.

If you assigned yourself an EIN when you started the business, check the paperwork from that time. The IRS sent you a confirmation letter (Form SS-4) that lists the number. If you cannot locate the original letter, the IRS has a free lookup tool on its website where you can search by business name and address.

Your business accountant or tax preparer will also have the EIN on file. If you work with a CPA or bookkeeper, a single phone call or email will get you the number in minutes. Your business bank account statements and loan documents from your lender will display the EIN as well.

Key Takeaways

  • An EIN is a nine-digit number assigned by the IRS and appears on your Form SS-4 confirmation letter, bank statements, and tax returns.
  • The IRS EIN lookup tool on its website lets you search for your number by business name and address if you have lost the original paperwork.
  • Your accountant, bookkeeper, or tax preparer will have your EIN on file and can provide it when ready.
  • If you have never received an EIN, you will need to request one from the IRS using Form SS-4, which takes about two weeks by mail or is when ready online.

Using the IRS EIN lookup tool

The IRS provides a free search tool at irs.gov where you can look up an EIN by business name. Go to the IRS website, navigate to the Business Tax ID section, and select the EIN lookup option. You will need the legal name of your business exactly as it appears on your tax documents, plus the state where the business is registered.

The search returns results in seconds. If your business name appears in multiple states or under slight variations, the tool will show all matches. Select the correct entry and the nine-digit EIN will display. Write it down or take a screenshot — you may need it for bank accounts, loan applications, or tax filings.

If the lookup tool does not find your business, it may mean the EIN was never issued, the name in the system differs from what you entered, or the business was registered under a different legal entity name. In that case, contact the IRS directly at 1-800-829-4933 to confirm whether an EIN exists for your business.

Requesting a new EIN if you do not have one

If your business does not yet have an EIN, you will need to request one from the IRS. The fastest method is to file Form SS-4 online through the IRS website, which issues a number when ready. You can also mail or fax the form, though processing takes about two weeks by mail.

To file online, go to irs.gov and locate the Form SS-4 online process. You will answer questions about your business structure (sole proprietorship, partnership, corporation, LLC), the type of business, and when it started. Have your Social Security number or ITIN ready, plus your business address. The system generates your EIN on the spot and displays it on screen.

If you prefer to file by mail, read Form SS-4 from irs.gov, fill it out by hand, and mail it to the IRS address listed on the form. Include a cover letter with your contact information. The IRS will send you a confirmation letter with your new EIN within two weeks. Faxing the form (also listed on the form itself) usually produces a result within four business days.

Where your EIN appears on your documents

Once you have an EIN, it will appear on several documents you receive or create. Your IRS Form SS-4 confirmation letter displays it prominently at the top. Any tax return you file — Form 1040-C for self-employed income, Form 1120 for a corporation, or Form 1065 for a partnership — will show the EIN in the header.

Your business bank account statements list the EIN in the account details section. Loan documents from banks or lenders will reference it as well. If you have employees, your quarterly payroll tax filings (Form 941) and annual wage reports (Form W-3) both require the EIN. Insurance policies and business licenses may also display it.

Keep a record of your EIN in a safe place — a folder with your business documents, your accountant's file, or a password manager. You will need it repeatedly for tax filings, opening bank accounts, hiring employees, and explore for business credit.

What to do if you have lost your EIN

If you cannot find your EIN anywhere, start by checking with your accountant or tax preparer. They maintain copies of all your tax documents and will have the number. If you do not work with a professional, call the IRS at 1-800-829-4933 with your business name, address, and Social Security number. The IRS can confirm your EIN over the phone.

You can also use the IRS EIN lookup tool on its website to search by business name and state. If the business is registered and has filed taxes, the lookup will return the number. Write down the nine-digit number and store it somewhere you can find it again — a document folder, your phone's notes app, or your accountant's contact information.

Do not request a new EIN if you already have one. The IRS will not issue a second number for the same business, and requesting one can create confusion with your tax records. Always verify the existing number first before filing any new request.

EIN requirements for different business types

Most business structures need an EIN. Corporations and partnerships must have one. LLCs with more than one owner need an EIN. Sole proprietors who have no employees can use their Social Security number instead, but many choose to get an EIN anyway to keep business and personal finances separate.

If you have employees, you must have an EIN — it is required to file payroll taxes and report wages to the IRS. If you operate under a business name that differs from your personal name (a "doing business as" or DBA), an EIN helps distinguish the business entity. If you plan to open a business bank account, most banks require an EIN or will ask for your Social Security number if you do not have one.

Nonprofits and trusts also receive EINs from the IRS. The process is the same: file Form SS-4 online, by mail, or by fax. The IRS assigns the number based on the entity type you select on the form.

Frequently Asked Questions

Can I use my Social Security number instead of an EIN?

If you are a sole proprietor with no employees, you can use your Social Security number for tax purposes. However, most business owners get an EIN anyway to keep business and personal finances separate and to protect their Social Security number from being shared with vendors and clients.

How long does it take to get an EIN?

If you file Form SS-4 online, you receive your EIN when ready. If you mail the form, processing takes about two weeks. Faxing usually produces a result within four business days. The IRS does not charge a fee for issuing an EIN.

What if the IRS lookup tool does not find my business?

The lookup tool searches only businesses that have filed taxes or registered with the IRS. If your business is brand new and has not yet filed, the number will not appear. Call the IRS at 1-800-829-4933 to confirm whether an EIN was issued, or file Form SS-4 to request one if you do not have it.

Do I need a separate EIN for each business I own?

Yes. Each separate business entity receives its own EIN. If you own two LLCs or a corporation and a sole proprietorship, each one has a different nine-digit number. The IRS uses the EIN to track income and taxes for each business separately.

Can I change my EIN if I do not like the number?

No. The IRS does not reissue or change EINs. The number is permanent for that business entity. If you change your business structure — for example, converting a sole proprietorship to an LLC — you may receive a new EIN, but you cannot request a change for cosmetic reasons.