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

Your tax identification number appears on tax forms you have filed, W-2s from employers, 1099s from contractors or banks, and letters from the IRS. If you cannot locate it in those places, you can call the IRS directly or request a transcript that shows your number. The IRS will not mail your number to you unprompted, so you have to take the step of asking for it.

The number you need depends on your situation. If you are a U.S. citizen or permanent resident who works, your number is your Social Security Number (SSN). If you are self-employed, a business owner, or a non-resident alien, you may have an Employer Identification Number (EIN) instead or in addition. Some people have both.

Key Takeaways

  • Your Social Security Number appears on W-2s, 1099s, and any tax return you have filed with the IRS.
  • You can call the IRS at 1-800-829-1040 during business hours and provide your name, date of birth, and address to confirm your number over the phone.
  • An IRS transcript (available free online at irs.gov or by mail) shows your tax ID and past filing history in one document.
  • If you have an Employer Identification Number for a business, that number appears on your EIN assignment letter from the IRS or on business tax returns you have filed.

Check documents you already have at home

Start with tax paperwork in your files. Look for any federal tax return you have filed — the number appears in the top-right corner of Form 1040 and most other IRS forms. If you filed jointly with a spouse, your individual number is listed first.

W-2s from employers and 1099s from banks, investment firms, or clients all show your tax ID in box 1 or the upper section. If you worked in the past year, a W-2 is usually the fastest source. Older 1099s work just as well. You do not need the most recent year — any year will show your number, since it does not change.

Check your mail from the IRS. When you first filed a tax return or opened a business, the IRS sent a letter confirming your number. These letters are often kept in a file or drawer. If you have an EIN for a business, look for the EIN assignment letter (Form SS-4 confirmation or a letter titled "Employer Identification Number").

Call the IRS to confirm your number by phone

The IRS will tell you your tax ID over the phone if you can verify your identity. Call 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 current address ready.

The IRS representative will ask you to confirm personal information before reading your number back to you. This is the fastest way to get your number if you do not have documents in front of you. Wait times are often long during tax season (January through April), so call early in the morning or in the fall if you can.

If you need your number in writing for a form or application, the phone call alone may not be enough — the organization asking for it may require a document with your signature or official IRS letterhead. In that case, request a transcript instead (see below).

Request an IRS transcript online or by mail

An IRS transcript is an official document that shows your tax ID, filing history, and income reported to the IRS. You can view and download it free at irs.gov using the "Get Your Tax Record" tool. You will need to create or log into an IRS online account and verify your identity using your Social Security Number, date of birth, filing status, and expected refund or tax owed from your most recent return.

The online transcript appears immediately and can be printed or saved as a PDF. This is the fastest route if you need a document to show to a bank, landlord, or government agency.

If you do not have online access or prefer a mailed copy, call 1-800-829-1040 and request Form 4506-C (Transcript Request). Mail the completed form to the IRS address shown on the form. Processing takes 5 to 10 business days by mail. You can also request a transcript in person at your local IRS office, though appointments are often booked weeks in advance.

Find an EIN if you own a business or are self-employed

If you registered a business with your state or filed a business tax return, you have an EIN. Look for the IRS letter you received when you applied for the number — it is usually titled "Employer Identification Number Assignment" or similar. The letter shows your nine-digit EIN in the format XX-XXXXXXX.

If you cannot find the letter, check any business tax returns you have filed (Form 1120, 1120-S, or 1065). Your EIN appears at the top of the form. You can also call the IRS Business and Specialty Tax Line at 1-800-829-4933 and provide your business name and the date you applied for the number.

If you applied for an EIN online at irs.gov but never received confirmation, log into your IRS online account and check your records. The confirmation page from your application may still be in your email inbox or browser history.

What to do if you have lost or forgotten your number

Do not panic — your number has not changed and is not lost. It is stored in IRS records tied to your name and date of birth. The methods above (calling the IRS, requesting a transcript, or checking old documents) will recover it.

If you have never filed a tax return and do not have a Social Security Number, you will need to apply for one through the Social Security Administration before you can file taxes. That is a separate process from finding an existing number.

If you believe someone has stolen your tax ID or filed taxes in your name, contact the IRS Identity Theft Hotline at 1-800-908-4490. They will help you place a fraud alert on your account and file an Identity Theft Affidavit (Form 14039).

Frequently Asked Questions

Can I look up someone else's tax ID?

No. The IRS will only confirm a tax ID to the person it belongs to or to an authorized representative (such as a tax preparer or attorney with power of attorney). You cannot retrieve another person's number by calling the IRS or requesting a transcript.

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

For most people, yes. Your Social Security Number is your tax ID. However, if you are self-employed or own a business, you may have both a Social Security Number and a separate Employer Identification Number. The EIN is used for business filings, while your SSN is used for personal tax returns.

How long does it take to get a transcript in the mail?

The IRS processes mailed transcript requests in 5 to 10 business days. If you need your number sooner, use the online tool at irs.gov (instant) or call 1-800-829-1040 (same day). During tax season, mail processing may take longer.

What if the IRS says they have no record of my number?

This usually means you have never filed a tax return or applied for an EIN under your name. If you worked and had taxes withheld, contact your employer for a copy of your W-2 — it will show the number the IRS has on file for you. If you are self-employed and have never filed, you will need to apply for an EIN through irs.gov or by mail using Form SS-4.