Your Tax ID is on documents you already have

Your tax ID number — also called an Employer Identification Number (EIN) if you own a business, or your Social Security Number (SSN) if you are an individual — appears on tax forms, bank statements, and employer records you receive regularly. You do not need to request it or search a government database. The number was assigned to you when you filed your first tax return or when your employer registered your business.

If you are an individual filing taxes, your tax ID is your Social Security Number. If you own a business — whether a sole proprietorship, partnership, LLC, or corporation — you have an EIN that is separate from your personal SSN. Both numbers serve the same purpose: they identify you to the IRS and to financial institutions.

Key Takeaways

  • Your Social Security Number is your tax ID if you file as an individual; your EIN is your tax ID if you own a business.
  • Your SSN appears on your Social Security card, tax returns, W-2 forms from employers, and bank statements.
  • Your EIN appears on business tax returns, bank statements for business accounts, and the IRS confirmation letter you received when the EIN was issued.
  • If you cannot locate your EIN, the IRS can confirm it by phone or mail using your business name and Social Security Number.

Finding your Social Security Number

Your Social Security Number is printed on your Social Security card, which you received from the Social Security Administration. If you have the card, the nine-digit number is right there. If you have lost the card, your SSN also appears on any tax return you filed — Form 1040, 1040-SR, or 1040-NR — in the top-left corner under your name.

You can also find your SSN on a W-2 form from any employer, a 1099 form if you received self-employment income, or a bank statement from any account you opened. Mortgage statements and loan documents also list your SSN. If you have filed taxes in the past three years, the IRS website (irs.gov) allows you to view your tax transcript, which displays your SSN and filing history.

Finding your Employer Identification Number

If you own a business and have an EIN, look for the IRS confirmation letter you received when you first applied for the number. This letter — called a Form SS-4 confirmation — was mailed to you and contains your nine-digit EIN. Keep this letter in a safe place; you will need it for banking, payroll, and tax filing.

Your EIN also appears on your business tax return (Form 1120, 1120-S, 1065, or 1040-C, depending on your business structure) and on business bank statements. If you have a payroll service or accountant, they have a copy of your EIN on file and can provide it to you when ready.

What to do if you cannot find your EIN

The IRS can confirm your EIN over the phone. Call the IRS 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, Social Security Number, and business address ready. The IRS representative will verify your identity and provide your EIN on the spot.

You can also request your EIN by mail. Send a letter to the IRS office that serves your state, include your business name and Social Security Number, and ask them to confirm your EIN. The response typically arrives within two to three weeks. A list of IRS addresses by state is available on irs.gov under "Contact Us."

Tax ID numbers for different business structures

A sole proprietor — someone who runs a business alone without forming an LLC or corporation — may use their Social Security Number as their tax ID instead of obtaining an EIN. However, if you have employees or operate as a corporation or partnership, you must have an EIN.

An LLC (Limited Liability Company) must obtain an EIN unless it is a single-member LLC with no employees, in which case the owner's SSN can be used. A partnership always requires an EIN. A corporation always requires an EIN. If you are unsure whether your business structure requires an EIN, the IRS website has a tool that walks you through your situation.

Keeping your tax ID find

Your tax ID number is sensitive information. Treat it the same way you treat a password: do not share it in emails, texts, or over the phone unless you initiated the contact and you are certain you are speaking with a legitimate business or government agency. Scammers sometimes pose as IRS agents and demand tax ID numbers over the phone.

The IRS will never contact you by phone, email, or text to demand your tax ID or threaten you with arrest. If someone contacts you claiming to be from the IRS and asking for your tax ID, hang up and call the IRS directly at the number on their official website.

Frequently Asked Questions

Can I use my Social Security Number instead of getting an EIN for my business?

Only if you are a sole proprietor with no employees. If you hire anyone or operate as an LLC, partnership, or corporation, you must obtain an EIN. Many sole proprietors get an EIN anyway to keep their personal and business finances separate.

What if I lost my Social Security card and do not have any tax documents?

Contact the Social Security Administration at 1-800-772-1213 or visit your local Social Security office. They can issue you a replacement card or provide your SSN in writing. You will need to show a government-issued ID and proof of citizenship or legal residency.

How long does it take to get an EIN?

If you explore online through irs.gov, you receive your EIN when ready. If you explore by phone, mail, or fax, the IRS issues it within four business days. The confirmation letter arrives by mail within two weeks.

Do I need a different tax ID for each business I own?

Yes. Each separate business — whether you own two LLCs, a corporation and a sole proprietorship, or any other combination — needs its own EIN. You can explore for multiple EINs using the same Social Security Number.