Where to Find Your Tax ID Number

Your tax identification number is printed on documents you already have. If you are a U.S. citizen or permanent resident, your number is your Social Security Number (SSN), which appears on your Social Security card. If you do not have a Social Security card or cannot locate it, the Social Security Administration will send you a replacement at no cost.

If you are not a U.S. citizen but need to file taxes or open a bank account, you may have an Individual Taxpayer Identification Number (ITIN) instead. An ITIN is a nine-digit number issued by the IRS to people who are required to have a U.S. tax identification number but are not may be able to access for a Social Security Number. If you applied for an ITIN, the IRS sent you a notice in the mail with your number on it.

If you own a business or operate as a sole proprietor, you may also have an Employer Identification Number (EIN), a separate nine-digit number used for business tax purposes. This is different from your personal tax ID and is used on business tax returns and when hiring employees.

Key Takeaways

  • Your Social Security Number is your primary tax identification number and is printed on your Social Security card, which you can request from the Social Security Administration if lost.
  • The IRS mailed your ITIN to you on a notice if you applied for one; check old tax documents or contact the IRS if you cannot find the notice.
  • Your EIN is a separate business identification number that appears on IRS correspondence about your business and on any business tax returns you filed.
  • All three numbers are nine digits long, but they serve different purposes: SSN for personal taxes, ITIN for non-citizens, and EIN for business entities.

Getting a Replacement Social Security Card

If you cannot find your Social Security card, you do not need to pay anyone to replace it. Visit your local Social Security office in person, or explore online at ssa.gov if you have a driver's license or state ID card. You will need to bring proof of citizenship (a birth certificate, passport, or naturalization papers) and proof of identity.

The Social Security Administration processes replacement cards within 10 to 14 business days if you explore in person. Online applications take longer. Once you receive your card, your nine-digit number will be printed on it. This is the number you use on tax forms, W-4s, and any other tax documents.

Locating an ITIN You Already Have

If you received an ITIN, the IRS sent you a notice by mail called a CP565 notice. This notice contains your nine-digit ITIN. Check your files from the year you applied, or look for any IRS correspondence you received around that time.

If you filed a tax return using your ITIN, that number appears on the return itself. Check copies of past returns you may have kept. If you cannot locate the notice or a return, you can contact the IRS at 1-800-829-1040 and provide your name, date of birth, and the year you applied for the ITIN. The IRS can confirm your number over the phone.

Finding Your EIN for Business Purposes

If you applied for an EIN, the IRS issued it to you when ready when you applied, either online at irs.gov or by phone at 1-800-829-4933. The IRS also mailed you a confirmation letter called a SS-4 confirmation with your EIN on it.

Check any business tax returns you filed — your EIN appears on the first page of Form 1120 (for corporations), Form 1065 (for partnerships), or Schedule C (for sole proprietors). You can also call the IRS Business and Specialty Tax Line at 1-800-829-4933 with your business name and the year you applied, and they will provide your EIN.

What to Do If You Never Received Your Number

If you applied for a Social Security Number, ITIN, or EIN but never received confirmation, contact the issuing agency directly. For Social Security Numbers, visit ssa.gov or call 1-800-772-1213. For ITINs and EINs, call the IRS at 1-800-829-1040.

Have your name, date of birth, and the date you applied ready when you call. The agency will tell you whether your process was processed and will provide your number if it was issued. If your process was never received, they can help you reapply.

Using Your Tax ID on Forms and Documents

Once you have located your number, you will use it on several documents. Your Social Security Number goes on your personal income tax return (Form 1040), your W-4 form (which you give to your employer), and any 1099 forms you receive from banks or other payers. Your ITIN is used the same way if you do not have a Social Security Number.

Your EIN goes on business tax returns and on forms you file with the IRS related to your business. If you hire employees, you provide your EIN to them so they can report your business on their W-2 forms. Banks and other financial institutions may also ask for your EIN when you open a business account.

Frequently Asked Questions

Can I look up my Social Security Number online?

You cannot look up your number through a public database, but you can create a my Social Security account at ssa.gov to view your earnings record and other information. Your number is printed on your Social Security card, which is the official document that shows it.

What if I have both an SSN and an ITIN?

If you have both numbers, use your Social Security Number on all tax forms and documents. An ITIN is only used if you do not have a Social Security Number. Once you receive your SSN, you do not need to use your ITIN anymore.

Is my tax ID number the same as my account number with the IRS?

Your tax ID number (SSN, ITIN, or EIN) is what the IRS uses to identify you or your business in their system. It is not the same as an account number, but it serves as your identifier for all IRS records and correspondence.

How do I know if my number is correct before filing taxes?

Double-check the number on your Social Security card, ITIN notice, or EIN confirmation letter against any documents you are about to file. Entering the wrong number can delay processing or cause your return to be rejected by the IRS.