Your Tax ID is on documents you already have
Your tax identification number appears on multiple documents the IRS and your employer have already sent you. The fastest way to find it is to check your most recent tax return, W-2 form, or a letter from the IRS. If you do not have those in front of you, you can request a replacement from the IRS or your employer within a few days.
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. Some people have both.
Key Takeaways
- Your Social Security Number appears on your most recent W-2, tax return, or any IRS letter sent to your home address.
- An Employer Identification Number is a nine-digit number issued to businesses and self-employed people, found on business tax returns or IRS correspondence.
- The IRS can mail you a replacement Social Security Number verification letter within 5 to 10 business days if you cannot locate your number.
- Your employer's payroll or human resources department can confirm your Social Security Number or provide a copy of your W-2 if you have lost it.
Finding your Social Security Number
Your Social Security Number is printed on your Social Security card itself. If you have the card, the nine-digit number is on the front. If you have lost the card, check any of these documents:
- Your most recent tax return (Form 1040 or similar)
- Your W-2 form from your employer
- Any letter from the IRS, including notices, refund letters, or tax transcripts
- Your birth certificate (does not show the number, but you can use it to request a replacement card)
- Bank statements or investment account statements
If you cannot find any of these documents, contact the Social Security Administration directly. You can call 1-800-772-1213 (TTY 1-800-325-0778) or visit your local Social Security office. Bring a photo ID and proof of citizenship or permanent residency. The SSA will verify your identity and can issue you a replacement card or a verification letter with your number on it.
Finding your Employer Identification Number
An Employer Identification Number is a nine-digit number assigned to businesses, partnerships, corporations, and self-employed people. If you own a business or are self-employed, your EIN appears on your business tax return (Form 1120, 1120-S, 1065, or Schedule C filed with your personal return).
Check these sources first:
- Your most recent business tax return
- IRS correspondence addressed to your business
- Your business bank account statements
- Your business license or registration documents
- Payroll records or W-2 forms you issued to employees
If you cannot locate your EIN, you can request it from the IRS. Call the Business and Specialty Tax Line at 1-800-829-4933 (Monday through Friday, 7 a.m. to 7 p.m. your local time). Have your business name, address, and Social Security Number ready. The IRS can tell you your EIN over the phone immediately, or mail you a verification letter within 5 to 10 business days.
Getting a replacement from your employer
If you work for someone else, your employer's payroll or human resources department has your Social Security Number on file. Contact them and ask for a copy of your most recent W-2 or a verification letter showing your name and Social Security Number. Most employers can provide this within one business day.
You do not need to explain why you need it. Employers routinely issue copies of W-2 forms and verification letters. If your employer is no longer in business or you cannot reach them, the IRS can provide a transcript of your tax return showing your Social Security Number. Request a tax transcript by calling 1-800-829-1040 or visiting IRS.gov.
Requesting documents from the IRS
The IRS can send you a letter confirming your Social Security Number or EIN. You have three options:
| Method | Time to receive | How to request |
|---|---|---|
| Phone | Immediate (verbal confirmation) | Call 1-800-829-1040 (SSN) or 1-800-829-4933 (EIN). Have ID ready. |
| 5 to 10 business days | Complete Form 4506-C and mail to your IRS service center. See IRS.gov for the address. | |
| Online account | Immediate | Create an account at IRS.gov and view your tax transcript, which shows your number. |
If you call the IRS, have your name, date of birth, and current address ready. If you mail a request, include your signature and the date. The IRS will mail the letter to the address on file with your most recent tax return.
What to do if you think your number has been misused
If you find your tax identification number but suspect someone else has used it, contact the IRS Identity Theft Hotline at 1-800-908-4490. You can also file a report with the Federal Trade Commission at IdentityTheft.gov. The IRS and FTC will guide you through next steps, which may include filing a police report or placing a fraud alert with credit bureaus.
Do not delay if you suspect misuse. The sooner you report it, the easier it is to prevent fraudulent tax returns filed in your name. Keep a record of the date you reported the issue and the name of the person you spoke with.
Frequently Asked Questions
Can I look up my Social Security Number online?
No. The Social Security Administration does not provide a public lookup tool. You must call 1-800-772-1213, visit a local SSA office, or check documents you already have. The IRS can confirm your number by phone if you call 1-800-829-1040.
What if I was born outside the United States?
If you are a permanent resident or authorized to work, you have a Social Security Number. If you are a non-resident alien or do not have work authorization, you may have an Individual Taxpayer Identification Number (ITIN) instead. Check your tax return or IRS correspondence to see which number you were assigned.
Do I need my tax ID number to file taxes?
Yes. You must provide your Social Security Number or EIN on any tax return you file. If you cannot locate it before the filing deadline, call the IRS immediately. They can confirm your number over the phone so you can complete your return.
How long does it take to get a replacement Social Security card?
The Social Security Administration typically mails a replacement card within 7 to 10 business days of your application. You can apply in person at a local SSA office or by mail. Bring a photo ID and proof of citizenship or permanent residency.