Your Federal Tax ID is a nine-digit number the IRS assigns to you

Your Federal Tax ID (also called an EIN or Employer Identification Number) is a nine-digit identifier the IRS uses to track your tax account. If you are self-employed, run a business, or file taxes as a sole proprietor, you need this number. The IRS issued it to you when you first registered with them — you do not request it each time you file.

Finding your existing Federal Tax ID takes minutes if you know where to look. Most people have one of three places where the number appears in their records. If you cannot locate it, the IRS can confirm it over the phone or by mail, though that process takes longer.

Key Takeaways

  • Your Federal Tax ID appears on past tax returns, IRS correspondence, and business bank account paperwork — check these first before contacting the IRS.
  • If you are self-employed and have never registered with the IRS, you may not have a Federal Tax ID yet and will need to request one.
  • The IRS can confirm your Federal Tax ID by phone at 1-800-829-4933 if you have your Social Security Number and other identifying information ready.
  • Business owners can look up their Federal Tax ID on the IRS Business Services Online portal if they have registered and set up login credentials.

Check your past tax returns and IRS letters first

The fastest way to find your Federal Tax ID is to look at documents you already have. If you filed a business tax return in the past — a Schedule C, Form 1040-ES, or Form 1120 — your Federal Tax ID appears at the top of the first page. Look for a nine-digit number formatted as XX-XXXXXXX.

Any letter from the IRS about your business or self-employment also contains your Federal Tax ID. These include notices about tax payments, correspondence about an audit, or confirmation letters when you first registered. Check the top right corner or the opening paragraph of the letter.

If you have a business bank account, your Federal Tax ID is on the account paperwork and statements. Lenders and credit card processors also have this number on file if you applied for business credit.

Call the IRS to confirm your Federal Tax ID

If you cannot find your Federal Tax ID in your records, the IRS can look it up for you by phone. Call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have your Social Security Number, date of birth, and business address ready. The IRS representative will confirm your Federal Tax ID on the call.

Wait times are shortest early in the morning and outside tax season (after April 15). During peak season, hold times can exceed 30 minutes. If you reach a representative, the call usually takes 5 to 10 minutes once they have your information.

The IRS does not issue Federal Tax IDs over the phone if you do not have one yet. If you are self-employed and have never registered, you will need to request one through a different process.

Request a new Federal Tax ID if you do not have one

If you are self-employed or run a business and have never registered with the IRS, you do not yet have a Federal Tax ID. You will need to request one before you file your first business tax return or open a business bank account.

The most common way to request a Federal Tax ID is to file Form SS-4 (Application for Employer Identification Number) with the IRS. You can file this form online through the IRS website, by fax, by mail, or by phone. Online filing is fastest — you receive your Federal Tax ID immediately after you submit the form.

To file online, go to the IRS website, select "Apply for an EIN Online," and complete the form. You will need your Social Security Number, business structure (sole proprietor, partnership, corporation), and business address. After you submit, the IRS displays your nine-digit Federal Tax ID on screen and sends a confirmation by mail within two weeks.

Use the IRS Business Services Online portal

If you have already registered your business with the IRS and set up login credentials, you can view your Federal Tax ID through the IRS Business Services Online portal. This portal is for business owners who have an existing account with the IRS.

To access it, go to the IRS website and select "Business Services Online." Log in with your username and password. Your Federal Tax ID appears in your account summary. If you do not have login credentials yet, you can create them during your first visit — the IRS will verify your identity by asking questions about your tax history.

This method works only if you have already filed a business tax return or registered with the IRS. New business owners should use Form SS-4 instead.

Mail a request to the IRS if you prefer written correspondence

You can also request your Federal Tax ID or confirm an existing one by mailing Form SS-4 to the IRS. Print the form from the IRS website, fill it out by hand or type it, and mail it to the address listed on the form (this varies by state).

Processing by mail takes 4 to 6 weeks. The IRS will mail your Federal Tax ID confirmation to the address you provide on the form. This method is slower than calling or filing online, but it creates a paper record if you need one for your business files.

Include a cover letter with your name, phone number, and a brief note explaining that you are requesting your Federal Tax ID. This helps the IRS route your form to the correct department.

Frequently Asked Questions

Is my Federal Tax ID the same as my Social Security Number?

No. Your Federal Tax ID is a separate nine-digit number the IRS assigns to your business or self-employment activity. Your Social Security Number is your personal identifier. Some sole proprietors use their Social Security Number as their Federal Tax ID, but most businesses have a distinct Federal Tax ID.

What if I lost my Federal Tax ID and cannot find it anywhere?

Call the IRS at 1-800-829-4933 with your Social Security Number and business address. They will confirm your existing Federal Tax ID. If you never registered, they will direct you to file Form SS-4 to request one.

How long does it take to get a Federal Tax ID if I request one online?

If you file Form SS-4 online through the IRS website, you receive your Federal Tax ID immediately after submission. The IRS also mails a confirmation letter within two weeks. By phone or mail, the process takes longer — phone requests are same-day, and mail requests take 4 to 6 weeks.

Do I need a Federal Tax ID if I am a sole proprietor with no employees?

Not always. Sole proprietors can use their Social Security Number on tax returns. However, you need a Federal Tax ID if you want a separate business bank account, hire employees, or file certain business tax forms. Many sole proprietors request one anyway to keep personal and business finances separate.