Your Federal Tax ID is on documents you already have

Your Federal Tax ID — also called an EIN (Employer Identification Number) or SSN (Social Security Number) — appears on tax forms you receive every year. If you are an individual filing taxes, your Social Security Number is your federal tax ID. If you own a business, you have an EIN instead. Both numbers are nine digits and formatted the same way on official documents.

You do not need to request a new number or contact the IRS to "find" one you already have. The number was issued to you when you were born (SSN) or when you registered your business (EIN). The fastest way to locate it is to check the documents sitting in your files right now.

Key Takeaways

  • Your Social Security Number is your federal tax ID if you file taxes as an individual; your EIN is your federal tax ID if you own a business.
  • Your SSN appears on your Social Security card, tax returns, W-2 forms, and 1099 forms you receive from employers or clients.
  • Your EIN appears on IRS correspondence, business tax returns, and bank account documents if you registered it with the IRS.
  • If you cannot locate your number on existing documents, the IRS can confirm it by phone or mail using your name and date of birth.
  • You do not need to pay anyone to find your federal tax ID — the IRS provides this information at no cost.

Where your Social Security Number appears

Start with the documents you received from your employer or clients. Your W-2 form (issued by employers) and 1099 forms (issued by clients or financial institutions) both display your Social Security Number in the upper left corner. If you filed a tax return in the past three years, your SSN is on the first page of that return in the top right corner.

Your original Social Security card also shows the number, though many people store this in a safe place and do not handle it often. If you have a state ID or driver's license, your SSN may appear on the back or in the state's records, though not always printed on the card itself. Bank statements and investment account statements often show your SSN as well.

If you have a copy of your birth certificate on file, the Social Security Administration may have issued a number at birth, but the number itself does not appear on the certificate — only on the card or in official correspondence from the SSA.

Where your EIN appears if you own a business

If you registered a business with the IRS, your EIN was issued and confirmed in writing. The IRS sends a Form SS-4 confirmation letter to the address you provided when you registered. This letter shows your nine-digit EIN and is the official record of your business tax ID. Keep this letter in your business files.

Your EIN also appears on any business tax returns you have filed (Form 1120 for corporations, Form 1065 for partnerships, Form 1040-SE for sole proprietors with an EIN). If you opened a business bank account, the bank may have asked for your EIN, and it will appear on bank statements and account documents.

If you have not yet registered for an EIN but think you need one, the IRS Form SS-4 is the document you file to request one. You can file it online, by phone, or by mail, and the IRS will issue a number when ready (or within four weeks by mail).

How to confirm your number with the IRS if you cannot find it

If you have searched your documents and cannot locate your Social Security Number or EIN, the IRS can confirm it for you. Call the IRS at 1-800-829-1040 during business hours (Monday through Friday, 7 a.m. to 7 p.m. your local time). Have your name, date of birth, and mailing address ready. The IRS representative will verify your identity and provide your number over the phone.

You can also write to the IRS at the address for your region (listed on IRS.gov under "Contact Us"). Include your name, date of birth, mailing address, and a brief explanation of why you need the number. The IRS will respond by mail within 30 days, though this method takes longer than calling.

For an EIN, you can call the IRS Business and Specialty Tax Line at 1-800-829-4933 during the same hours. Have your business name, business address, and the date you registered on hand.

What to do if you think your number was issued but you have no record

If you believe you have a Social Security Number (for example, you worked in the United States years ago) but have no card or documents, contact the Social Security Administration directly at 1-800-772-1213. They can search their records by your name and date of birth and issue you a replacement card if a number exists.

If you are a non-citizen who worked in the United States on a visa, your SSN may be on file with the IRS even if you no longer have the card. The IRS can confirm this by phone using the number above.

If you are self-employed and registered a business years ago but lost the confirmation letter, the IRS can look up your EIN by business name and your personal Social Security Number. This search takes a few minutes on the phone.

Why you need your federal tax ID and when to have it ready

You will need your federal tax ID when you file a tax return, open a bank account, explore for credit, or report income to the IRS. Employers and clients need it to issue W-2 and 1099 forms. If you own a business, you need your EIN to hire employees, open a business bank account, and file business tax returns.

Keep your Social Security Number private — do not share it on unsecured websites or with people who call you unexpectedly. The IRS and Social Security Administration never contact people by phone or email asking for a Social Security Number. If someone claims to be from the IRS and asks for your number, hang up and call the IRS directly using the number on their official website.

Frequently Asked Questions

Is my Social Security Number the same as my federal tax ID?

Yes, if you file taxes as an individual. Your SSN is your federal tax ID. If you own a business, your EIN is your federal tax ID instead. You may have both numbers if you are self-employed with an EIN and also file personal tax returns using your SSN.

Can I get a new federal tax ID if I want a different number?

No. Your Social Security Number and EIN are permanent. You cannot request a new one unless you have a documented reason (such as identity theft). The IRS does not issue replacement numbers for privacy or preference reasons.

What if I lost my Social Security card?

You do not need the physical card to file taxes or use your number. The card is just proof of the number. If you need a replacement card, contact the Social Security Administration at 1-800-772-1213 or visit your local SSA office. They will issue a new card at no cost.

Do I need an EIN if I am a sole proprietor?

Not always. Sole proprietors can use their Social Security Number as their business tax ID. You only need an EIN if you hire employees, operate as an LLC or corporation, or want to keep your business and personal finances separate. The choice is yours.

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

If you file Form SS-4 online or by phone, the IRS issues your EIN when ready. If you file by mail, it takes up to four weeks. You can use the EIN right away even if you have not received the confirmation letter yet.