Your tax ID is on documents you already have or can request from the IRS

Your tax identification number is a nine-digit number the IRS assigns to you for tax purposes. If you are a U.S. citizen or permanent resident with a Social Security number, that number is your tax ID. If you do not have a Social Security number, the IRS issues a separate Individual Taxpayer Identification Number (ITIN) instead. You do not need to "find" or request your tax ID if you already know your Social Security number — they are the same thing.

The fastest way to locate your tax ID is to check documents you have at home. If you do not have those documents or cannot remember your number, you can contact the IRS directly or request a transcript that shows it.

Key Takeaways

  • Your Social Security number is your tax identification number if you are a U.S. citizen or permanent resident.
  • Check your prior tax returns, W-2 forms, 1099 forms, or bank statements — your tax ID appears on all of these.
  • If you have lost your number, call the IRS at 1-800-829-1040 during business hours and have your name, date of birth, and address ready.
  • You can also request a tax return transcript from the IRS, which displays your tax ID and takes one to two weeks by mail.
  • If you are not a U.S. citizen and do not have a Social Security number, you may have an ITIN instead, which you can verify the same way.

Check documents you already have at home

Your tax identification number appears on several documents most people keep or can retrieve easily. Look for a prior year tax return — the number is printed at the top of Form 1040 or any other federal tax form you filed. If you filed taxes in the past five years, the IRS can send you a copy if you no longer have the original.

Check any W-2 form from an employer or a 1099 form from a bank, investment account, or contractor work. Both show your tax ID in the upper left corner. Bank statements and brokerage statements also display it. If you have a mortgage or car loan, the lender has your tax ID on file and it may appear on statements or closing documents.

Social Security cards themselves print the number clearly, though the card is not required to prove your tax ID to anyone — the number alone is sufficient.

Call the IRS to confirm your number by phone

The IRS will confirm your tax identification number over the phone if you call 1-800-829-1040. This line is available Monday through Friday, 7 a.m. to 7 p.m. in your local time zone. Have your name, date of birth, and current address ready. The IRS representative will verify your identity using this information and then tell you your number.

Wait times can be long during tax season (January through April), so calling outside those months is faster. If you reach a representative, the call takes about five minutes once your identity is confirmed.

Request a tax return transcript from the IRS

A tax return transcript is an official IRS document that shows your tax ID, filing status, and income reported on your return for a specific year. You can request one free of charge through three methods: online, by phone, or by mail.

The fastest method is the IRS website at irs.gov. Go to "Get Your Tax Record" and select "Transcript of Your Return." You will need to verify your identity using either your Social Security number and tax return information or by creating an IRS online account. The transcript downloads immediately as a PDF.

By phone, call 1-800-829-1040 and ask for a transcript. The IRS mails it to you within one to two weeks. By mail, complete Form 4506-C and mail it to the IRS address listed on the form — this also takes one to two weeks. All three methods are free.

What to do if you have an ITIN instead of a Social Security number

If you are not a U.S. citizen and do not have a Social Security number, the IRS may have issued you an Individual Taxpayer Identification Number (ITIN). An ITIN is a nine-digit number formatted like a Social Security number but beginning with 9. It serves as your tax identification number for filing returns and other tax purposes.

You can locate your ITIN the same way you would locate a Social Security number: check prior tax returns, W-2s, or 1099s. If you need to confirm it, call the IRS at 1-800-829-1040 or request a transcript. ITINs are issued only by the IRS, not by Social Security, so the IRS is the only source that can verify one.

ITINs expire if you do not file a tax return for three consecutive years. If your ITIN has expired, you will need to reapply using Form W-7 and supporting documents that prove your identity and foreign status.

What happens if you cannot locate your number anywhere

If you have never filed a tax return, never received a W-2 or 1099, and do not have a Social Security card, you may not have been assigned a tax ID yet. In that case, you will receive one automatically when you file your first tax return or when you apply for a Social Security number.

If you believe you should have a tax ID but cannot find it after checking documents and calling the IRS, ask the IRS representative whether there is a record of you in their system. Sometimes a number was issued but never used, or records may show a different spelling of your name or an outdated address. The IRS can update your information and confirm whether a number exists.

Frequently Asked Questions

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

Yes, if you are a U.S. citizen or permanent resident with a Social Security number. The IRS uses your Social Security number as your tax identification number. They are the same nine-digit number. If you do not have a Social Security number, the IRS issues a separate ITIN instead.

Can I look up someone else's tax identification number?

No. The IRS will only confirm a tax ID to the person it belongs to, and only after verifying their identity. You cannot retrieve another person's number by calling the IRS or requesting a transcript. If you need someone's tax ID for a business or legal reason, you must ask them directly.

What if my tax ID was stolen or compromised?

Contact the IRS Identity Theft Hotline at 1-800-908-4490. The IRS can place a flag on your account and issue you a new ITIN if you have one, though Social Security numbers cannot be changed. File a report with the Federal Trade Commission at identitytheft.gov and consider placing a fraud alert with the credit bureaus.

Do I need my tax ID to open a bank account or get a job?

Most employers and banks will ask for your Social Security number or tax ID during the application process. Have it ready, but you do not need to memorize it — you can look it up beforehand using the methods in this guide. If you do not have one yet, you can apply for a Social Security number through your local Social Security office.