Your Tax ID is on documents you already have

Your tax identification number appears on several documents the IRS and your employer have already sent you. For most people, it is your Social Security number. If you do not have a Social Security number, the IRS issues an Individual Taxpayer Identification Number (ITIN) instead. The fastest way to find it is to check the documents listed below — you do not need to contact the IRS first.

If you have filed taxes before, your number is on every tax return you submitted. If you have never filed, it is on your Social Security card or the IRS notice that assigned your ITIN. Employers also send this number on your W-2 form each January.

Key Takeaways

  • Your tax ID is your Social Security number in most cases, or an ITIN if you do not have a Social Security number.
  • Check your Social Security card, past tax returns, W-2 forms, or IRS notices — your number appears on all of these.
  • If you cannot find it in those places, you can request a transcript from the IRS or call the Social Security Administration.
  • The IRS does not mail tax ID numbers on their own; they appear only on documents related to taxes, employment, or Social Security.

Documents that show your tax identification number

Start with the documents you have at home. Your Social Security card shows your nine-digit number in the center. If you have filed a tax return in the past five years, that return shows your number at the top. Your W-2 form, sent by your employer each January, displays it in box a on the upper right.

If you received an ITIN from the IRS instead of a Social Security number, look for the notice the IRS sent when they assigned it. That notice, called a CP565 or similar letter, contains your ITIN. You may also see it on any tax return you filed using that number.

Bank statements, investment account statements, and mortgage documents sometimes show the last four digits of your tax ID for verification purposes, but they do not show the full number. These are not reliable sources for finding your complete number.

How to request your number from the IRS

If you cannot locate your number in any of the documents above, you can request a tax transcript from the IRS. A transcript shows your filing history and includes your tax identification number. You can order a transcript online at IRS.gov, by phone at 1-800-908-9946, or by mail using Form 4506-C.

The online method is fastest — you can often view your transcript the same day if you have a filing history with the IRS. By phone, the IRS can tell you your number immediately if you can answer security questions about your past tax returns. By mail, allow 5 to 10 business days.

You will need to verify your identity before the IRS releases your number. Have your Social Security card, driver's license, or passport ready. If you are calling, the IRS will ask questions about your past returns or personal history.

How to request your number from Social Security

If you lost your Social Security card and cannot find your number anywhere else, you can contact the Social Security Administration directly. Call 1-800-772-1213 (TTY 1-800-325-0778) or visit your local Social Security office in person.

Social Security can tell you your number over the phone if you can verify your identity. They will ask for your full name, date of birth, place of birth, and mother's maiden name. You can also request a replacement Social Security card, which will show your number again.

If you are applying for an ITIN and do not yet have a number, you cannot get one from Social Security — you must apply through the IRS using Form W-7. You will need a valid passport or national ID from your country of origin, plus documentation of your immigration status or tax filing reason.

What to do if you never had a tax ID assigned

If you have never worked in the United States and have never filed a tax return, you may not have a tax identification number yet. You will need one if you plan to work, file taxes, or open certain bank accounts.

If you are a U.S. citizen or permanent resident, you can apply for a Social Security number through the Social Security Administration. Visit your local Social Security office with your birth certificate, state ID or passport, and proof of your address (a utility bill or lease). Processing takes one to two weeks.

If you are not a U.S. citizen, you can apply for an ITIN through the IRS using Form W-7. You will need a valid passport or national ID, proof of your immigration status or reason for needing a tax ID, and a completed tax return (if you are filing). The IRS processes ITIN applications in about two to four weeks.

Why you need your tax ID and where it is used

Your tax identification number is required whenever you file a tax return, open a bank or investment account, apply for credit, or start a job. Employers use it to report your wages to the IRS. Banks use it to report interest and dividends. The IRS uses it to track your tax history and any money owed.

You may also need your tax ID to claim certain government benefits, enroll in health insurance through the marketplace, or apply for housing assistance. Some programs ask for it to verify your identity and income. Having your number readily available speeds up these processes.

Frequently Asked Questions

Is my tax ID the same as my Social Security number?

For most people, yes. Your Social Security number is your tax identification number. If you do not have a Social Security number, the IRS issues an ITIN, which serves the same purpose for tax filing. Both are nine-digit numbers.

Can I look up someone else's tax ID?

No. Tax identification numbers are private information protected by federal law. Only the person themselves, their authorized representative, or certain government agencies can access it. Employers and financial institutions can see your number only when you provide it to them directly.

What if my tax ID was stolen or compromised?

Contact the IRS immediately at 1-800-908-9946 and report the theft. You can also file a report with the Federal Trade Commission at IdentityTheft.gov. The IRS can place a fraud alert on your account and help you monitor for unauthorized use of your number.

Do I need to memorize my tax ID?

You do not need to memorize it, but it is useful to write it down and store it safely at home. Keep a copy with your important documents. You will need it frequently for employment, banking, and tax filing, so having it easily accessible saves time.