Your Tax ID is on documents you already have

Your Tax ID — also called an EIN (Employer Identification Number) if you run a business, or your SSN (Social Security Number) if you file as an individual — appears on paperwork the IRS has already sent you. You do not need to request it again. For most people, it is your Social Security Number. For businesses, nonprofits, and self-employed people with employees, it is a separate nine-digit number the IRS issued when you registered.

The documents below are the fastest places to look. If you cannot find it in any of them, the IRS website has a tool to retrieve it, and you can also call the IRS directly.

Key Takeaways

  • Your Tax ID is your Social Security Number if you file taxes as an individual with no business employees.
  • If you own a business or nonprofit, your Tax ID is a separate nine-digit EIN the IRS issued when you registered — check your IRS correspondence or business registration documents first.
  • Past tax returns, W-2 forms, and 1099 forms all display your Tax ID at the top.
  • The IRS Online Account tool at irs.gov lets you retrieve your EIN without calling, and you can also phone the IRS Business and Specialty Tax Line at 1-800-829-4933.

Check your past tax returns

Open any federal tax return you filed in the last three years. Your Tax ID appears in the top-left corner of the first page, above your name and address. If you filed jointly with a spouse, your Social Security Number is listed first, followed by your spouse's.

If you filed a business return (Form 1120, 1120-S, or 1065), your EIN is printed at the top. If you cannot locate a paper copy, you can read prior-year returns from your IRS Online Account at irs.gov — log in with your Social Security Number and create an account if you do not have one yet.

Look at W-2 and 1099 forms

Any W-2 (wage and income statement) or 1099 form (contractor income, interest, dividends) you received from an employer or client shows your Tax ID in Box a. W-2 forms arrive by January 31 each year; 1099 forms arrive by January 31 as well, though some arrive later.

If you received these forms electronically, check your email or the payroll portal where your employer or client sent them. If you received paper copies, they are usually filed with your tax documents or in a folder labeled "Tax" or "Income."

Find your EIN on IRS correspondence

If you own a business or nonprofit, the IRS sent you a letter when your EIN was issued — usually Form SS-4 confirmation or a letter titled "EIN Assignment." This letter contains your nine-digit EIN and is often kept with business registration documents or tax files.

Check folders labeled "Business Registration," "IRS," or "Tax Documents." If you filed a business tax return, the EIN also appears at the top of that return. State business registration documents (your Articles of Incorporation or business license) may reference the EIN as well, though they do not always print the full number.

Use the IRS Online Account tool

Go to irs.gov and select "Sign in to your online account." Create an account using your Social Security Number, email address, and identity verification. Once logged in, navigate to "Tax Records" or "Account Information" — the exact label varies by account type.

For business owners, the IRS Online Account displays your EIN under "Business Information" or "Entity Information." The tool works during business hours and does not require a phone call. If you have trouble logging in, the IRS offers a phone verification option as part of the sign-in process.

Call the IRS directly

If you cannot locate your Tax ID through documents or the online tool, call the IRS. For individual Social Security Numbers, call the main IRS line at 1-800-829-1040. For business EINs, call the Business and Specialty Tax Line at 1-800-829-4933. Both lines are open Monday through Friday, 7 a.m. to 7 p.m. your local time.

Have your name, address, and date of birth ready. If you are calling about a business EIN, also have your business name and the date you registered it. Wait times are typically shorter early in the morning and outside tax season (after April 15). The IRS may ask security questions to confirm your identity before providing the number.

What to do if you never received an EIN

If you registered a business but never received an EIN confirmation letter, the IRS may not have processed your registration. Check your email (including spam folders) for any IRS correspondence. If nothing arrived, call the Business and Specialty Tax Line at 1-800-829-4933 to confirm whether an EIN was issued.

If no EIN exists, you will need to register again. You can register online at irs.gov using Form SS-4, by mail, or by phone. Online registration is fastest — the IRS issues your EIN when ready after you submit the form, and you can use it right away.

Frequently Asked Questions

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

Only if you file taxes as an individual with no business employees. If you own a business, operate a nonprofit, or have employees, your Tax ID is a separate nine-digit EIN. You will have both numbers — your Social Security Number and your EIN.

Can I look up someone else's Tax ID?

No. The IRS does not release Tax IDs for other people. You can only retrieve your own Tax ID or, if you own a business, your business EIN. If you need a business's EIN for payment or vendor purposes, ask the business directly or check their website.

What if I lost my Social Security card and need my number?

You do not need the card itself — your Social Security Number appears on tax returns, W-2 forms, and bank statements. If you need an official replacement card, contact the Social Security Administration at ssa.gov or visit your local Social Security office. Bring a photo ID and proof of citizenship or legal residency.

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

If you register online at irs.gov using Form SS-4, you receive your EIN when ready. If you register by mail or phone, it takes about two weeks. You can use your EIN as soon as you receive it, even if your business has not yet filed a tax return.

Do I need a Tax ID to open a business bank account?

Most banks require an EIN for a business account, even if you are a sole proprietor. Some banks accept a Social Security Number instead, but an EIN keeps your personal and business finances separate and is worth obtaining before you open the account. Register at irs.gov if you do not have one yet.