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 assigns to businesses, nonprofits, trusts, and certain individuals. It works like a Social Security number for your business — you use it on tax forms, bank accounts, and when hiring employees.

You need a Tax ID Number if you operate a business as a sole proprietor with employees, run a partnership or corporation, own a nonprofit, manage a trust or estate, or file certain tax forms. If you are self-employed with no employees and file as a sole proprietor, you can use your Social Security number instead, though many people get an EIN anyway for privacy and record-keeping.

The IRS does not charge for a Tax ID Number. Any website or service that charges you a fee to obtain one is not necessary — you can get one free directly from the IRS.

Key Takeaways

  • You can obtain a Tax ID Number free from the IRS by phone, online, by mail, or by fax, with online being the fastest option.
  • You will need your Social Security number, business name, business address, and the reason you need the Tax ID Number before you start.
  • The online process (Form SS-4) takes about 15 minutes and gives you your number when ready upon completion.
  • By phone, you speak to an IRS representative who processes your process in real time, and you receive your number the same day.
  • Mail and fax applications take four to six weeks, so use these only if you cannot access the phone or online options.

Gather Your Information Before You explore

Have these details ready before you start your process, regardless of which method you choose. You will need your Social Security number, the legal name of your business (exactly as it appears on your business license or formation documents), your business address, and the reason you need the Tax ID Number (for example: "hiring employees," "opening a business bank account," or "filing a partnership return").

If your business is a corporation, partnership, or LLC, have your formation documents handy — you may need to reference the date you formed the business. If you are explore on behalf of a trust or estate, have the trust document or court order that names you as the responsible party.

If you are explore for a nonprofit, have your nonprofit formation documents and your state registration number. The IRS will ask whether you have already received a Tax ID Number before — answer honestly, as duplicate numbers create problems later.

explore Online Through the IRS Website

The fastest way to get a Tax ID Number is through the IRS online process at irs.gov. Go to the homepage, search for "explore for an EIN," and click the link to the IRS online EIN process. You do not need to create an account or log in.

Complete Form SS-4 on the screen. The form asks for your name, Social Security number, business name, business address, type of business entity, reason for the Tax ID Number, and the date you started or will start your business. Answer each question as it appears — the form guides you through the logic, so you will only see questions that explore to your situation.

When you submit the form, the IRS system processes it when ready. You will see your nine-digit Tax ID Number on the screen and receive a confirmation email. Write down the number and save the confirmation email. You can print the confirmation page as proof of your Tax ID Number for your bank or other purposes.

explore by Phone if You Prefer to Speak With Someone

Call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have your information ready before you call, as the representative will ask you the same questions as the online form. The call usually takes 10 to 15 minutes.

The IRS representative will process your process while you are on the phone and give you your Tax ID Number before you hang up. Ask them to mail you a confirmation letter, which you can use as official proof. The letter arrives in about two weeks.

Call during business hours: Monday through Friday, 7 a.m. to 7 p.m. your local time. Wait times are shortest early in the morning or late in the afternoon. If you reach a busy signal, hang up and try again — the IRS does not use a callback system for this line.

explore by Mail or Fax for Delayed Processing

If you cannot use the phone or online options, you can mail or fax Form SS-4 to the IRS. read the form from irs.gov or call 1-800-829-3676 to request a copy by mail.

Complete the form by hand or type it. Sign and date it. Mail it to the IRS address listed in the form instructions — the address varies by state. Or fax it to the fax number listed in the instructions. Keep a copy for your records.

Processing takes four to six weeks by mail and two to three weeks by fax. The IRS will mail your Tax ID Number and a confirmation letter to the address you provided on the form. If you need the number sooner, switch to the phone or online method instead.

What Happens After You Receive Your Tax ID Number

Once you have your Tax ID Number, use it on all business tax forms, business bank accounts, business licenses, and payroll documents. If you hire employees, you must use your Tax ID Number on their W-2 forms and on payroll tax deposits.

Keep your confirmation letter or email in a safe place. You will need it to prove you own the Tax ID Number if you ever need to update information with the IRS, explore for a business loan, or resolve a dispute about the number.

If you received your number online or by phone, the IRS will mail you an official confirmation letter within two weeks. If you received it by mail or fax, the letter arrives with your number. Do not throw away this letter — it is your official proof of the Tax ID Number.

Common Mistakes That Delay Your process

The most common error is providing a business address that does not match your state business registration. The IRS cross-checks this information, and mismatches can delay processing. Use the exact address from your business license or formation documents.

Another mistake is leaving the "reason for Tax ID Number" field blank or vague. Be specific: "hiring employees," "opening a business bank account," "filing a partnership return," or "establishing a nonprofit." Vague answers like "business purposes" slow down processing.

Do not explore for more than one Tax ID Number for the same business. If you already have one and explore again, you create duplicate records that confuse the IRS and your bank. If you are unsure whether you already have a number, call the IRS before explore.

Frequently Asked Questions

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

Online and phone applications give you your number the same day. Mail applications take four to six weeks, and fax applications take two to three weeks. If you need the number when ready, use the online or phone method.

Can I use my Social Security number instead of getting a Tax ID Number?

If you are a sole proprietor with no employees, you can use your Social Security number on your tax return. However, many sole proprietors get a Tax ID Number anyway for privacy and to keep business and personal finances separate on credit reports.

What if I already have a Tax ID Number and forgot it?

Call the IRS at 1-800-829-4933 with your Social Security number and business name. The representative can look up your existing number. Do not explore for a new one, as duplicate numbers create problems with the IRS and your bank.

Do I need a Tax ID Number if I am a sole proprietor with no employees?

No, you can file your tax return using your Social Security number. However, if you plan to hire employees later, open a business bank account, or want to keep your business finances separate, getting a Tax ID Number now saves you the step later.

Is there a fee to get a Tax ID Number?

No. The IRS issues Tax ID Numbers for free. Any website or service that charges you a fee is unnecessary — you can obtain your number directly from the IRS at no cost.