Your tax ID is printed on documents the IRS has already sent you

Your tax ID is a nine-digit number the IRS uses to track your tax account. If you are a U.S. citizen or resident alien, your tax ID is your Social Security number. If you do not have a Social Security number, the IRS issues a separate nine-digit number called an Individual Taxpayer Identification Number (ITIN).

You do not need to request your tax ID — you already have one. The number appears on documents you have received from the government or your employer. The fastest way to find it is to look at a document you already have at home.

Key Takeaways

  • Your Social Security number is your tax ID if you are a U.S. citizen or resident alien, and you can find it on your Social Security card, tax returns, or W-2 forms.
  • If you do not have a Social Security number, look for your ITIN on IRS correspondence, Form W-7, or documents the IRS sent you when you filed a tax return.
  • Your employer's records show your tax ID on every pay stub and W-2 form they issue.
  • If you cannot locate your tax ID in any document, you can call the IRS directly or check your online IRS account through IRS.gov.

Finding your Social Security number

Your Social Security number appears on your physical Social Security card, which the Social Security Administration mailed to you when you first received the number. If you still have that card, the nine-digit number is printed on the front.

If you cannot find your card, check any tax return you have filed. The number appears on the first page of Form 1040 (the main federal income tax form) and on any W-2 form your employer sent you. These documents are usually in a folder with your tax records or in email if your employer sent them electronically.

Your Social Security number also appears on any bank or investment account statements, mortgage paperwork, or loan documents you signed. It may be partially masked (showing only the last four digits) on recent statements for security reasons, but older documents often show the full number.

Finding your ITIN if you do not have a Social Security number

An ITIN is a nine-digit number that looks like a Social Security number but starts with the number 9. The IRS issues ITINs to people who are not may be able to access for a Social Security number but need to file a U.S. tax return or report income to the IRS.

Your ITIN appears on any IRS letter or notice you have received. Check your mail from the IRS carefully — the number is usually in the upper right corner of the letter. If you filed a tax return using an ITIN, the number is on Form 1040 and on any IRS correspondence related to that return.

If you filed Form W-7 (process for IRS Individual Taxpayer Identification Number) to request an ITIN, that form shows your number. The IRS also mailed you a separate letter confirming your ITIN when it was first issued.

Checking your employer's records

Your employer has your tax ID on file and prints it on every pay stub you receive. Look at any recent pay stub — your Social Security number or ITIN appears in a section labeled "Employee Tax ID", "SSN", or "ITIN", usually near your name and address.

Your employer also sends you a Form W-2 (Wage and Tax Statement) every January for the previous year. This form shows your tax ID prominently on the front. If you have filed taxes before, you have received at least one W-2, and it is likely still in your records or available from your employer's human resources department.

Using your online IRS account

You can view your tax ID by logging into your account on IRS.gov. Go to the IRS website, select "Sign in to your account", and follow the steps to create or access your account. You will need to verify your identity using information from your tax return or other government records.

Once you are logged in, your tax ID appears in the account summary section. This method works whether you have a Social Security number or an ITIN. If you have never filed a tax return, you may not be able to create an online account, since the IRS uses tax return information to verify your identity.

Calling the IRS directly

If you cannot find your tax ID in any document and cannot access your online IRS account, you can call the IRS. The main IRS phone line is 1-800-829-1040. Have your name, date of birth, and current address ready when you call.

Wait times are often long, especially during tax season (January through April). The IRS also offers a callback service on its website — you can request a call instead of waiting on hold. Be prepared to answer security questions to verify your identity before the IRS will share your tax ID over the phone.

What to do if your tax ID has been compromised

If you believe someone has used your Social Security number or ITIN fraudulently, contact the IRS when ready. Call 1-800-829-0582 to report identity theft. The IRS has a dedicated team for these cases and can place a flag on your account to prevent fraudulent filings.

You should also file a report with the Federal Trade Commission at IdentityTheft.gov and consider placing a fraud alert with the three major credit bureaus (Equifax, Experian, and TransUnion). Keep records of all your reports and correspondence with the IRS, as you may need them if someone files a fraudulent tax return in your name.

Frequently Asked Questions

Is my tax ID the same as my account number on my tax return?

No. Your tax ID (Social Security number or ITIN) is the nine-digit number the IRS uses to identify you. Your account number is a separate reference number the IRS assigns to your specific tax account. Both appear on your tax return, but you only need your tax ID for most purposes.

Can I change my tax ID?

No. Your Social Security number and ITIN are permanent. You cannot request a new number just because you want a different one. If your number has been compromised, you can work with the IRS and Social Security Administration to protect your account, but the number itself does not change.

Do I need to memorize my tax ID?

You do not need to memorize it, but it is helpful to know it. Write it down and store it in a safe place, such as a locked drawer or safe. Do not share your tax ID with anyone except your employer, your tax preparer, financial institutions, and government agencies that request it.

What if I lost my Social Security card?

You do not need the physical card to know your number. Your Social Security number is on any tax return, W-2, or bank statement you have. If you need a replacement card, you can request one from the Social Security Administration, but you can still file taxes and work without it as long as you know your number.

Can I use my ITIN to open a bank account?

Most banks will accept an ITIN to open a checking or savings account, though some have restrictions. Call your bank before visiting to confirm they accept ITINs. You will need to bring your ITIN documentation (such as an IRS letter) and a government-issued photo ID.