What a Tax ID Number Is and Who Needs One

A Tax ID Number (also called an Employer Identification Number or EIN) is a nine-digit code the IRS uses to identify your business, nonprofit, or other entity for tax purposes. If you are self-employed, run a business with employees, operate a partnership, or manage a nonprofit, you will need one. The IRS also issues Tax ID Numbers to sole proprietors who hire workers, even if they operate under their own name.

You do not need a Tax ID Number if you are a sole proprietor with no employees and no business structure — in that case, the IRS uses your Social Security Number instead. But if you want to keep your personal and business finances separate, or if you plan to hire anyone, a Tax ID Number is the practical choice.

Key Takeaways

  • You can get a Tax ID Number free from the IRS online, by phone, by mail, or in person at an IRS office, with online being the fastest route.
  • The online application (Form SS-4) takes about 15 minutes and you receive your number immediately after submission.
  • By phone, you call the IRS Business and Specialty Tax Line and receive your number the same day, though wait times vary by season.
  • By mail or fax, the process takes two to four weeks, so use this route only if you cannot access online or phone options.
  • You will need your Social Security Number, the business start date, and the type of business structure (sole proprietor, LLC, corporation, partnership, or nonprofit).

Getting a Tax ID Number Online (Fastest Route)

The IRS online system is the quickest way to get a Tax ID Number. You go to the IRS website, fill out Form SS-4 in your browser, and receive your number immediately after you submit it. The form takes about 15 minutes and asks for your name, address, Social Security Number, business name, business address, type of business structure, and the date you started or plan to start the business.

After you submit the form online, the IRS displays your Tax ID Number on the screen. You can print it right away or save it. The IRS also mails you a formal notice (Form SS-4 confirmation) within two weeks, but you can use the number immediately for opening a bank account, hiring employees, or filing taxes. This route works if you have a computer and internet access and are applying for yourself or on behalf of a business you own or manage.

Getting a Tax ID Number by Phone

If you prefer to speak with someone, you can call the IRS Business and Specialty Tax Line at 1-800-829-4933. You will need the same information as the online form: your Social Security Number, business structure type, business start date, and business address. The representative will ask you questions, enter your information into their system, and give you your Tax ID Number over the phone during the same call.

Phone wait times are typically shorter on weekday mornings and longer during tax season (January through April). If you call and reach a long wait, you can call back at a different time or use the online method instead. Write down your Tax ID Number as soon as you receive it, and ask the representative to mail you a confirmation letter if you want a paper record.

Getting a Tax ID Number by Mail or Fax

You can mail or fax Form SS-4 to the IRS if you cannot use the online or phone options. Download the form from the IRS website, fill it out by hand or on your computer, and mail it to the address listed on the form (which varies by state) or fax it to the fax number provided. The IRS processes mail applications in two to four weeks and fax applications in one to two weeks.

Use this route only if you have a reason to avoid online and phone — for example, if you do not have internet access or a working phone number. The wait time is much longer than other methods, so plan ahead if you need the number by a specific date. The IRS will mail you your Tax ID Number and a formal notice once they process your form.

What Information You Need Before You Apply

Gather these items before you start the application, no matter which method you choose. You will need your Social Security Number, the legal name of your business (or your own name if you are a sole proprietor), your business address, the date you started or plan to start the business, and your business structure type (sole proprietor, partnership, LLC, S corporation, C corporation, nonprofit, trust, or other).

If you are applying on behalf of a business you do not own — for example, if you are a manager or officer — you will also need the owner's Social Security Number or Tax ID Number. If the business has a principal officer or responsible party who is not you, have their information ready as well. The IRS asks these questions to confirm the person applying has authority to request the number.

Using Your Tax ID Number After You Receive It

Once you have your Tax ID Number, use it on all business tax forms, bank account applications, and payroll documents. If you hire employees, you must provide your Tax ID Number to them and to the IRS when you file payroll taxes. If you open a business bank account, the bank will ask for your Tax ID Number during the account setup process.

Keep your Tax ID Number in a safe place — write it down or save it in a secure file. You will use it every year when you file business taxes, and you may need it if you apply for business loans, licenses, or permits. The IRS does not issue duplicate numbers, so if you lose track of yours, you can call the IRS to confirm the number they have on file for your business.

Frequently Asked Questions

Do I need a Tax ID Number if I am self-employed and work alone?

No, not required. The IRS uses your Social Security Number for your taxes if you are a sole proprietor with no employees. However, many self-employed people get a Tax ID Number anyway to keep business and personal finances separate and to protect their Social Security Number from being shared with clients or vendors.

How long does it take to get a Tax ID Number?

Online: immediate (you receive it on screen). By phone: same day. By fax: one to two weeks. By mail: two to four weeks. If you need the number quickly, use the online or phone method.

Can I get a Tax ID Number if I do not have a Social Security Number?

No. The IRS requires a Social Security Number or Individual Taxpayer Identification Number (ITIN) to issue a Tax ID Number. If you do not have either, you will need to apply for one first through the Social Security Administration or the IRS.

What if I already have a Tax ID Number and need to confirm it?

Call the IRS Business and Specialty Tax Line at 1-800-829-4933 with your business name and address, and they will confirm your number. You can also check your IRS correspondence — your Tax ID Number appears on all official letters and notices the IRS sends you.

Can I change my Tax ID Number after I receive it?

No. The IRS does not reissue or change Tax ID Numbers. If you made an error on your application, contact the IRS to correct the information on file, but your number stays the same. If you close your business and start a new one, you will need a new Tax ID Number for the new business.