Where to find your EIN if you already have one

Your Employer Identification Number (EIN) is a nine-digit code the IRS assigns to your business. If you have already received one, it appears on several documents you likely have at home right now.

Check your IRS correspondence first — any letter from the IRS about your business will have your EIN printed near the top. Look for Form SS-4 confirmation, which is what the IRS sends after you request an EIN. If you filed business tax returns, your EIN is on the first page of those returns. Your business bank account paperwork also lists it, because banks require an EIN to open a business account. Some people find it fastest to call their accountant or bookkeeper, who keeps a copy on file.

Key Takeaways

  • Your EIN appears on IRS letters, tax returns, and business bank statements if you have already received one.
  • You can search for a lost EIN using the IRS Business Services Online tool by entering your business name, address, and responsible party information.
  • If you have never received an EIN, you request one through the IRS using Form SS-4, either by mail, fax, phone, or online.
  • The IRS issues EINs when ready by phone or online, but mailed requests take four weeks.
  • You need an EIN only if you have employees, operate as a partnership or corporation, or file certain business tax returns.

Using the IRS Business Services Online tool to locate your EIN

If you cannot find your EIN in your paperwork, the IRS lets you search for it online through Business Services Online at the IRS website. You will need to register for an account using your Social Security Number or EIN (which creates a catch-22 if you have lost both, but most people have at least one).

Once logged in, you can search by business name and address. The system will return your EIN if the IRS has a record of it. This search works only if your business is registered with the IRS — sole proprietors who have never filed a business tax return or requested an EIN will not appear in the system. The search is free and takes a few minutes.

Requesting an EIN if you do not have one yet

If you have never received an EIN and need one, you request it from the IRS using Form SS-4. The form asks for your business name, address, type of business structure, and the name of the person responsible for the business. You do not need a lawyer or accountant to fill it out — the form itself walks you through each question.

You have four ways to submit Form SS-4: online through the IRS website (fastest), by phone at 1-800-829-4933, by fax, or by mail. The online method and phone method issue your EIN when ready or within minutes. If you mail the form, the IRS takes about four weeks to process it and send your EIN by mail. Faxed requests typically return a result within one business day.

What information you need to request an EIN

Before you start Form SS-4, gather these details: your legal business name, the business address, your home address, your Social Security Number or ITIN, the type of business (sole proprietorship, partnership, LLC, corporation, and so on), and the date you started or plan to start the business. If you have employees or plan to hire them, have their start date ready.

You will also need to name a responsible party — the person who owns or manages the business. This is usually the owner, but it can be a manager or partner. The IRS uses this name to match your EIN to your business if you call with questions later. Have that person's Social Security Number or ITIN on hand.

When you actually need an EIN

Not every business owner needs an EIN. A sole proprietor with no employees can use their Social Security Number on tax returns instead. However, you must have an EIN if you have employees (even one part-time worker), operate as a partnership, form an LLC or corporation, or file certain business tax returns like employment tax returns or excise tax returns.

Many sole proprietors request an EIN anyway because it keeps their Social Security Number off business documents and bank accounts, which is a privacy choice rather than a legal requirement. If you are unsure whether you need one, the IRS website has a tool that walks through your situation, or you can ask a tax professional.

What to do if the IRS cannot find your EIN record

If you search the Business Services Online tool and your EIN does not appear, it may mean the IRS has no record of your business. This happens if you requested an EIN years ago and the IRS closed the file because you did not file returns for several years, or if there was an error when the EIN was originally issued.

Call the IRS at 1-800-829-4933 and speak to a representative. Have your business name, address, and the responsible party's Social Security Number ready. The representative can search their system by hand and may be able to locate your original EIN or help you request a new one. If your business was closed and you need a fresh EIN for a new business, you straightforward request one using Form SS-4 again.

Keeping your EIN safe and organized

Once you have your EIN, write it down and store it somewhere you can find it again — a folder with your business documents, a note in your phone, or a file with your accountant. You will need it every time you file a business tax return, open a business bank account, hire an employee, or explore for a business loan or license.

Do not share your EIN publicly or with people who do not have a business reason to see it. Treat it like a Social Security Number for your business. If you suspect someone has misused your EIN, contact the IRS Identity Theft hotline at 1-800-908-4490.

Frequently Asked Questions

Can I look up someone else's EIN?

No. The IRS does not release EINs to the public. You can only search for your own EIN using Business Services Online, and you need to register with your own Social Security Number or EIN to do so. If you need a vendor's or client's EIN for business purposes, you have to ask them directly.

What if I requested an EIN but never received the confirmation letter?

If you requested an EIN by phone or online, you should have received it when ready — the IRS gives it to you during the call or shows it on screen. If you requested by mail or fax and never received a letter after four to six weeks, call the IRS at 1-800-829-4933 with your business name and address. They can confirm whether the EIN was issued and resend the letter.

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

Yes. Each separate business needs its own EIN, even if you own multiple businesses. The EIN ties to the business entity, not to you as a person. If you operate two unrelated businesses, you request two separate EINs using Form SS-4 for each one.

How long does it take to get an EIN by mail?

The IRS takes about four weeks to process a mailed Form SS-4 and send your EIN confirmation letter. If you need an EIN faster, use the online method (when ready) or call 1-800-829-4933 (when ready or within minutes). Faxed requests usually return a result within one business day.

Can I use my Social Security Number instead of an EIN on my tax return?

Yes, if you are a sole proprietor with no employees. You can use your Social Security Number on your Schedule C and other business tax forms. However, many sole proprietors request an EIN anyway to keep their Social Security Number off business documents and bank accounts.