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 identifier the IRS uses to track a business, nonprofit, or other entity for tax purposes. If you are a sole proprietor working under your own name, you can use your Social Security Number instead. If you have employees, operate as a partnership or corporation, or run a business under a name different from your own, you need an EIN.

The IRS issues EINs free of charge. You do not pay a fee to request one, and no legitimate government office will charge you for it. The number itself never expires, though you may need to renew your registration with the IRS if you do not file taxes for a certain period.

Getting an EIN is straightforward if you know which form to file and where to send it. The process takes anywhere from a few minutes (if you explore online) to several weeks (if you mail a paper form). Most businesses need one before they open a bank account or hire their first employee.

Key Takeaways

  • You can obtain an EIN online through the IRS website in minutes, by phone during business hours, by mail, or through a tax professional.
  • Online process through the IRS is the fastest method and requires Form SS-4, though you do not mail it — you fill it out on the IRS website.
  • If you explore by phone, call the IRS Business and Specialty Tax Line at 1-800-829-4933 during weekday business hours.
  • Paper applications take four to six weeks and require Form SS-4 mailed to the IRS address for your state.
  • You will need your Social Security Number, business structure type (sole proprietor, LLC, corporation, etc.), and the date you plan to start or started your business.

explore Online Through the IRS Website

The fastest way to get an EIN is to explore online at the IRS website. Go to irs.gov, search for "explore for an EIN Online," and you will land on the IRS's online process portal. The process takes about 15 minutes and you receive your number when ready after submission.

You will need to provide your name, address, Social Security Number, and information about your business: its legal name, the name you operate under (if different), your business structure (sole proprietor, partnership, S corporation, C corporation, LLC, nonprofit, etc.), and the date you started or plan to start. The IRS also asks what your business does and how many employees you have or plan to hire.

After you submit, the IRS displays your EIN on screen and sends a confirmation to the email address you provided. Write down the number when ready — you will need it to open a bank account, file taxes, and hire employees. The IRS also mails a formal letter with your EIN within two weeks, but you can use the number right away.

explore by Phone

If you prefer to speak with someone or cannot access the online system, you can call the IRS Business and Specialty Tax Line at 1-800-829-4933. The line is open Monday through Friday, 7 a.m. to 7 p.m. Eastern Time. Have your Social Security Number, business information, and the date you started your business ready before you call.

An IRS representative will ask you the same questions as the online form and issue your EIN over the phone. You receive the number when ready and can use it right away. The IRS mails a confirmation letter within two weeks. Wait times can be long during tax season (January through April), so call early in the morning or later in the week if possible.

explore by Mail

If you do not have internet access or prefer a paper trail, you can mail Form SS-4 (process for an Employer Identification Number) to the IRS. read the form from irs.gov or request it by calling 1-800-829-3676. Fill out the form completely, sign and date it, and mail it to the address for your state (the form lists all state addresses on the back).

Processing takes four to six weeks. The IRS mails your EIN and a formal letter to the address you provided on the form. If you need the number sooner, do not use the mail route — explore online or by phone instead. Keep a copy of the form you mailed for your records.

Using a Tax Professional or Accountant

If you work with a CPA, tax attorney, or bookkeeper, they can request an EIN on your behalf. Many do this as part of their startup services. You will still need to provide your Social Security Number and business information, but the professional handles the paperwork and submission. This route is useful if you are setting up a complex business structure (such as a multi-member LLC or S corporation) and want professional guidance on the form itself.

Tax professionals can explore online or by phone using a special IRS authorization process. The timeline is the same as explore yourself — when ready if online or by phone, four to six weeks if by mail. Some professionals charge a small fee for this service, typically $50 to $150, though many include it free as part of a startup package.

What Happens After You Receive Your EIN

Once you have your EIN, use it on all business documents, tax forms, and bank account applications. Your bank will ask for it when you open a business checking account. The IRS uses it to track your business tax filings, payroll taxes (if you have employees), and annual returns.

Keep your EIN and the IRS confirmation letter in a safe place. You will need both if you ever need to prove your business identity or if the IRS contacts you about your account. If you lose the letter, you can request a new one by calling the IRS or visiting irs.gov.

If your business structure changes (for example, you convert from a sole proprietor to an LLC), you may need a new EIN. If you sell your business or it closes, notify the IRS so they can mark your EIN as inactive. The number itself does not expire, but the IRS tracks whether it is still in use.

Common Mistakes to Avoid

Do not provide false information on your process. The IRS cross-checks your Social Security Number and business details against other records. Lying about your business structure or start date can delay processing or trigger an audit later.

Do not confuse an EIN with a business license. An EIN is a federal tax identifier; a business license is issued by your city or state and is a separate requirement. You need both, but they serve different purposes and come from different agencies.

Do not wait to explore if you are hiring employees. You must have an EIN before you can file payroll taxes or I-9 forms. If you are starting a business with employees, explore for your EIN before your first hire date.

Do not pay anyone to get an EIN for you. The IRS issues them free. Scams that charge a fee are fraudulent. If someone claims they can get you an EIN faster or cheaper than the IRS, they are lying.

Frequently Asked Questions

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

Yes, if you are a sole proprietor with no employees and operate under your own name. Many small one-person businesses use their SSN for tax purposes. However, if you hire anyone, operate under a business name, or want to keep your personal and business finances separate, you need an EIN.

How long does it take to get an EIN?

Online and phone applications are when ready — you receive your number the same day. Paper applications take four to six weeks. If you need the number urgently, do not use mail; explore online or call the IRS instead.

Do I need an EIN before I open a business bank account?

Most banks require an EIN (or your SSN if you are a sole proprietor) to open a business account. Some banks will let you open an account with an process receipt while you wait for your formal EIN letter, but it is easier to have the number first. explore online or by phone to get it the same day.

What if I applied online but did not write down my EIN?

Call the IRS at 1-800-829-4933 with your Social Security Number and business information, and they will provide it again. You can also wait for the confirmation letter, which arrives within two weeks. Do not delay opening your bank account — the IRS can confirm your number by phone when ready.

Can I change my EIN if I do not like the number?

No. The IRS assigns EINs randomly and does not reissue them based on preference. Your EIN is permanent for that business entity. If you truly need a different number, you would have to close the business and start a new one, which is not practical and may create tax complications.