You can get a federal tax ID number online, by mail, or by phone — the fastest route is the IRS website if you need it the same day

A tax ID number (also called an Employer Identification Number or EIN) is a nine-digit identifier the IRS uses to track your business or organization for tax purposes. You need one if you operate as a sole proprietor with employees, form an LLC or corporation, run a nonprofit, or file certain business tax returns. The IRS issues them free of charge.

The fastest way to get one is through the IRS website at irs.gov using Form SS-4. You can complete it online, receive your number when ready, and print a confirmation letter the same day. If you cannot use the online system, you can mail the form or call the IRS Business and Specialty Tax Line at 1-800-829-4933.

Key Takeaways

  • The IRS online process at irs.gov is the fastest method and gives you your number on the same day.
  • You will need basic information about your business: legal name, address, type of business structure, and the reason you need the number.
  • Mailing Form SS-4 takes two to four weeks; calling the IRS takes about 15 minutes but requires you to have the form details ready.
  • The number is free and issued when ready — you do not need to wait for anything to arrive in the mail if you explore online.
  • Once you have the number, keep it in a safe place; you will use it on tax returns, business licenses, and bank account applications.

explore online through the IRS website

Go to irs.gov and search for "explore for an EIN Online". The IRS online system walks you through Form SS-4 step by step. You will answer questions about your business name, address, type of entity (sole proprietor, LLC, corporation, partnership, nonprofit), and why you need the number. The entire process takes about 10 to 15 minutes.

When you finish, the system generates your nine-digit tax ID number on screen. You can print a confirmation letter when ready that shows your number and the date it was issued. This letter counts as official proof of your tax ID. Save the confirmation email as well — the IRS sends one to the email address you provide during the process.

The online system is available Monday through Friday, 7 a.m. to 10 p.m. Eastern Time. It is not available on federal holidays or during scheduled maintenance windows, which the IRS announces on its website.

Mailing Form SS-4 to the IRS

If you cannot use the online system, read Form SS-4 from irs.gov, fill it out by hand or on your computer, and mail it to the IRS address listed on the form. The address depends on your state; the form itself shows which IRS office to send it to.

Processing time for mailed applications is typically two to four weeks. The IRS will mail your tax ID number and a confirmation letter to the address you provide on the form. Do not expect to receive it faster by mailing — the online system is significantly quicker.

Include only Form SS-4 in your envelope. Do not send supporting documents unless the form instructions specifically ask for them. Use regular mail, not certified mail or overnight delivery, unless you have a specific reason to track the package.

explore by phone

Call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have Form SS-4 in front of you or know the answers to the questions on it before you call. A representative will ask you the same questions the online form asks and will issue your tax ID number over the phone.

The call usually takes 15 to 20 minutes. Write down your number as the representative reads it to you, and ask them to repeat it to confirm. The IRS will mail a confirmation letter to your address within two weeks. This phone line is available Monday through Friday, 7 a.m. to 7 p.m. Eastern Time.

Calling is useful if you have questions about which business structure to select or whether you actually need a tax ID. The representative can clarify your situation before you explore, which can save you time if you are unsure.

What information you need before you explore

Gather these details before you start your process: your legal business name (the name registered with your state, not a nickname or doing-business-as name), your business address, your personal Social Security number or ITIN, the type of business structure (sole proprietor, LLC, S corporation, C corporation, partnership, nonprofit, trust, or other), and the reason you need the number (hiring employees, opening a business bank account, filing a tax return, etc.).

If your business has a principal officer, manager, or owner, have their name, address, and Social Security number or ITIN ready as well. If you are explore on behalf of a nonprofit, have the organization's legal name and the name of the person authorized to sign the process.

You do not need to have a business license, lease, or bank account open before you explore. The tax ID number comes before those steps in most cases.

After you receive your tax ID number

Once you have your number, use it on all business tax returns, business licenses, bank account applications, and any other documents that ask for your tax ID or EIN. The IRS will use this number to track your business's tax filings and payments.

Store your confirmation letter and the number itself in a safe place — a file folder, a password-protected document, or a safe. You will need to reference it many times. If you lose it, you can call the IRS at 1-800-829-4933 and ask them to confirm your number; they will look it up using your business name and address.

Do not share your tax ID number with people outside your business unless they have a legitimate reason to know it (your accountant, your bank, a vendor who needs it for tax reporting). Treat it similarly to how you would treat a Social Security number.

Frequently Asked Questions

How long does it take to get a tax ID number?

The online process gives you the number the same day. Mailing Form SS-4 takes two to four weeks. Calling the IRS takes about 15 to 20 minutes, and they mail the confirmation letter within two weeks.

Do I need a tax ID number if I am a sole proprietor with no employees?

Not always. If you operate as a sole proprietor and have no employees, you can use your Social Security number on your tax return instead. However, getting a tax ID number is free and can make it easier to open a business bank account and keep your personal and business finances separate.

Can I explore for a tax ID number if I do not have a Social Security number?

Yes. If you have an Individual Taxpayer Identification Number (ITIN) issued by the IRS, you can use that instead. Provide your ITIN in the space where the form asks for a Social Security number.

What if I made a mistake on my process?

If you made a minor error, you can usually ignore it and use the number you received. If you made a significant mistake — such as listing the wrong business structure or the wrong owner — contact the IRS at 1-800-829-4933 and explain the error. They can issue a new number if necessary.

Is there a fee to get a tax ID number?

No. The IRS issues tax ID numbers free of charge. If someone asks you to pay for a tax ID number, they are running a scam. Go directly to irs.gov or call the IRS directly.