Your Tax ID is on documents you already have

Your Tax ID number (also called an EIN, ITIN, or SSN depending on your situation) appears on multiple documents the IRS or your employer has already sent you. You do not need to request it or contact anyone — you are looking for a number that was issued to you in the past. The document you check depends on what type of Tax ID you hold.

If you are a U.S. citizen or permanent resident, your Tax ID is your Social Security number. If you are not authorized to work but file taxes, you have an Individual Taxpayer Identification Number (ITIN). If you own a business or are a sole proprietor, you may have an Employer Identification Number (EIN). Each one appears in different places.

Key Takeaways

  • Your Social Security number is your Tax ID if you are a U.S. citizen or permanent resident, and it appears on your Social Security card, tax returns, and W-2 forms.
  • An ITIN (Individual Taxpayer Identification Number) is issued by the IRS to non-citizens who file taxes, and you can find it on your IRS notice letter or past tax returns.
  • An EIN (Employer Identification Number) for a business appears on IRS correspondence, your business tax returns, and the original EIN assignment letter.
  • If you cannot locate your number in any document, you can contact the IRS directly or request a transcript of your tax return, which includes your Tax ID.

Finding your Social Security number

Your Social Security number is printed on your Social Security card. This is the most direct source. If you have the card, the nine-digit number is displayed in the center.

If you do not have your card, check any of these documents: your most recent W-2 form (sent by your employer each January), your 1040 tax return (the main federal tax form), a 1099 form (issued if you received income from self-employment or investments), or any IRS notice or letter you have received. Your Social Security number appears at the top of all tax forms and IRS correspondence.

You can also request a replacement Social Security card from your local Social Security Administration office. Bring a photo ID and proof of citizenship or legal residency. There is no cost for a replacement card.

Finding your ITIN (Individual Taxpayer Identification Number)

If you filed taxes but do not have a Social Security number, the IRS issued you an ITIN. This nine-digit number looks like a Social Security number but starts with 9 and appears in a different range (typically 9XX-XX-XXXX).

Your ITIN appears on the IRS Notice of ITIN Assignment (Form W-7), which was mailed to you when your ITIN was first issued. If you kept this letter, your ITIN is printed on it. Your ITIN also appears on any tax return you filed after receiving it — check your copy of your 1040 form or any amended return.

If you cannot find the original assignment letter or a past return, contact the IRS at 1-800-829-1040 and request a transcript of your account. The transcript will show your ITIN and your filing history. You will need to verify your identity by providing your date of birth and the address on file with the IRS.

Finding your EIN (Employer Identification Number)

If you own a business or operate as a sole proprietor, you may have an EIN. This is a nine-digit number issued by the IRS to identify your business for tax purposes.

Your EIN appears on the IRS Form SS-4 confirmation letter, which was mailed to you when you first applied for the number. This letter is the clearest source. Your EIN also appears on your business tax return (Form 1120 for corporations, Form 1065 for partnerships, or Schedule C if you are a sole proprietor filing on your personal 1040).

If you applied for your EIN online through the IRS website, you received a confirmation number immediately and the EIN was displayed on screen. Check any emails or documents you saved from that application. If you cannot locate the original letter or return, call the IRS Business and Specialty Tax Line at 1-800-829-4933 and provide your business name and address. They can confirm your EIN over the phone.

Requesting a tax transcript if you cannot find your number

A tax transcript is an official IRS document that shows your filing history and includes your Tax ID number. You can request one free of charge from the IRS.

The fastest method is to order online at IRS.gov/transcripts. You will need to verify your identity using your Social Security number, date of birth, and filing status. If you cannot verify online, you can request a transcript by mail using Form 4506-C or by phone at 1-800-829-1040. By mail, transcripts arrive in 5 to 10 business days. By phone, the IRS can sometimes read your information to you immediately or mail it within a week.

When you receive your transcript, your Tax ID number will be printed at the top. Keep a copy for your records.

What to do if you have never received a Tax ID

If you believe you should have a Tax ID but have never received one, the next step depends on your situation. U.S. citizens and permanent residents can apply for a Social Security number at their local Social Security Administration office. Non-citizens who file taxes can apply for an ITIN by completing Form W-7 and submitting it to the IRS with proof of identity and tax residency. Business owners can apply for an EIN online at IRS.gov/ein or by phone at 1-800-829-4933.

Do not assume you need a new number if you simply cannot locate an old one. Most people who have worked or filed taxes already have a Tax ID on file with the IRS. Requesting a transcript or contacting the IRS directly is faster than applying for a new one.

Frequently Asked Questions

What if I lost my Social Security card and do not remember my number?

Check any tax return, W-2, or bank statement you have — your Social Security number appears on all of these. If you cannot find it in any document, call the Social Security Administration at 1-800-772-1213 with your name, date of birth, and place of birth. They can confirm your number over the phone.

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

No. Your Tax ID (Social Security number, ITIN, or EIN) is your identifier. Your IRS account number is different and appears on IRS notices. You only need your Tax ID for most purposes — tax forms, employment, and financial accounts.

Can I change my Tax ID number?

Social Security numbers and ITINs cannot be changed. EINs can be changed only in limited circumstances, such as a change in business structure. Contact the IRS if you believe your number was issued in error or if you have concerns about identity theft.

Do I need my Tax ID to file taxes online?

Yes. Tax software and the IRS require your Tax ID to file any return. If you do not have one, you must obtain one before filing — either a Social Security number, ITIN, or EIN depending on your situation.