Your Tax ID Number Appears on Multiple Documents You Already Have

Your tax ID number is printed on documents the IRS and your employer have already sent you. For most people, it is your Social Security number. If you are self-employed or run a business, you have an Employer Identification Number (EIN) instead, which the IRS issued when you registered your business. The fastest way to find it is to check the papers in front of you before calling anyone.

The specific document depends on your situation. A W-2 form from your employer, a 1099 form for freelance income, a bank statement, or a mortgage statement all display your tax ID. If you have filed taxes before, your prior year return shows it clearly. None of these require a phone call or a new request — you likely have them already.

Key Takeaways

  • Your tax ID number appears on your W-2, 1099, prior tax returns, bank statements, and mortgage statements without needing to request it.
  • For employees, your tax ID is your Social Security number; for business owners, it is your Employer Identification Number (EIN).
  • The IRS website lets you look up an EIN you registered if you have lost the original letter, but you need your business information to do so.
  • If you have never worked or filed taxes, you can request a Social Security number from the Social Security Administration or an EIN from the IRS directly.

Check Your W-2 or 1099 Form First

Your employer sends a W-2 form every January for the previous year's wages. Your tax ID number appears in the top right corner of the form, labeled as your Social Security number. If you are self-employed or received income from a client who paid you more than $600, you will receive a 1099-NEC or 1099-MISC form instead, which also displays your tax ID in the same location.

These forms arrive by mail or email, depending on your employer's preference. If you cannot find the current year's form, check your email spam folder or contact your employer's payroll department directly — they can print a copy or confirm the number over the phone. You do not need to request a new form just to see your tax ID; the old one will work.

Look at Your Prior Year Tax Return

If you filed taxes in previous years, your tax return shows your tax ID number on the first page. The number appears next to your name at the top of Form 1040 (the main federal income tax form). This is often the easiest place to find it because you likely have the return saved or printed at home.

You can also retrieve a copy of your return from the IRS if you have lost the original. The IRS Free File program and the IRS website both allow you to view prior returns you filed electronically. If you filed on paper, you can request a transcript of your return by calling the IRS at 1-800-829-1040 or by mailing Form 4506-C to your local IRS office.

Find an EIN on the IRS Business Services Online Portal

If you are a business owner and have lost the letter the IRS sent when you registered your EIN, you can look it up on the IRS website without calling. Visit the IRS Business Services Online portal and select "EIN Lookup." You will need your business name, business address, and the responsible party's name and Social Security number to search.

The lookup tool returns your EIN when ready if the information matches what the IRS has on file. This is faster than calling the IRS Business and Specialty Tax Line at 1-800-829-4933, though that line can also provide your EIN if you have the required information ready. The IRS typically responds to phone calls within 15 minutes during business hours.

Request a Social Security Number or EIN if You Do Not Have One

If you have never worked or filed taxes and do not have a Social Security number, you can request one from the Social Security Administration. Visit your local Social Security office in person with proof of age, citizenship or immigration status, and identity. You can also mail Form SS-5 to your regional Social Security office if you prefer not to visit in person. Processing takes about two weeks by mail.

If you are starting a business and do not yet have an EIN, you can request one from the IRS when ready at no cost. The fastest method is to explore online at the IRS website using Form SS-4. You will receive your EIN the same day. You can also mail the form or call the IRS Business and Specialty Tax Line, though both take longer — mailed applications take about four weeks, and phone lines can have wait times during tax season.

Check Bank and Mortgage Statements

Your bank and mortgage lender also have your tax ID number on file and display it on statements. Open a recent bank statement or mortgage statement and look for your Social Security number or EIN in the account information section. This is often printed on the first page or in the account summary area.

This method works if you have lost all other documents but still have active accounts. It is less common than checking a W-2 or tax return, but it is a reliable backup if those are not available. If you cannot find it on the statement itself, call your bank or lender's customer service line with your account number and they can confirm it verbally.

Contact the IRS Directly if You Cannot Locate It

If you have searched all the places above and still cannot find your tax ID number, you can call the IRS directly. The main IRS phone line is 1-800-829-1040. Have your name, date of birth, and address ready. The IRS can confirm your Social Security number or EIN over the phone, though wait times are often long during tax season (January through April).

If you are calling about a business EIN, use the IRS Business and Specialty Tax Line at 1-800-829-4933 instead. Both lines are open Monday through Friday, 7 a.m. to 7 p.m. your local time. If you prefer not to call, you can also mail a written request to your local IRS office, though this takes several weeks for a response.

Frequently Asked Questions

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

For most people, yes. Your Social Security number is your tax ID. If you are self-employed or own a business, you have a separate Employer Identification Number (EIN) that the IRS issued for your business. You may have both — your Social Security number for personal taxes and an EIN for business taxes.

Can I find my tax ID number online without calling the IRS?

If you have an EIN, you can look it up on the IRS Business Services Online portal if you have your business information. For a Social Security number, you cannot look it up online through the IRS, but you can find it on any W-2, 1099, prior tax return, or bank statement you have. If you have none of these, you will need to call or visit the Social Security Administration in person.

What if I lost my Social Security card and cannot find any documents with the number?

You can request a replacement Social Security card from the Social Security Administration by visiting your local office in person or mailing Form SS-5. You will need proof of age, citizenship or immigration status, and identity. Processing takes about two weeks by mail and is when ready if you explore in person.

How long does it take to get an EIN if I just started a business?

If you explore online through the IRS website, you receive your EIN the same day. If you mail Form SS-4, processing takes about four weeks. Phone applications through the IRS Business and Specialty Tax Line also take several days to a week, depending on call volume.

Do I need my tax ID number to file taxes?

Yes. You must provide your tax ID number on any tax return you file. If you do not have one yet, you must obtain a Social Security number or EIN before you can file. The IRS will not process a return without a valid tax ID number.