How to Get a Tax ID Number

What a Tax ID Is and Who Needs One

A Tax ID — also called an Employer Identification Number (EIN) or Federal Employer Identification Number — is a nine-digit number the IRS uses to identify your business, nonprofit, or self-employment activity for tax purposes. It works like a Social Security number, but for your business entity rather than a person.

You need a Tax ID if you operate a business as a sole proprietor, partnership, corporation, LLC, nonprofit, or any other structure that files taxes separately from your personal return. If you are self-employed and have no employees, you may be able to use your Social Security number instead, but many self-employed people get a Tax ID to keep their business and personal finances separate.

The IRS does not charge a fee to get a Tax ID. The process is free and takes between a few minutes and a few weeks depending on which method you use.

Key Takeaways

You can get a Tax ID online through the IRS website in about 15 minutes, and you receive your number immediately.
By mail or phone, the process takes one to two weeks, and you need to fill out Form SS-4 or call the IRS Business and Specialty Tax Line.
You will need your Social Security number or Individual Taxpayer Identification Number, your business address, and the date you started or plan to start your business.
Once you have your Tax ID, you use it on all business tax forms, bank accounts, and when hiring employees.

Getting a Tax ID Online (Fastest Route)

The fastest way to get a Tax ID is through the IRS website using the online EIN application tool. You go to irs.gov, search for "Apply for an EIN Online," and complete the form on the IRS Interactive Tax Assistant. The entire process takes about 15 minutes, and you receive your Tax ID number on screen immediately after you submit.

To use the online tool, you need a valid Social Security number or Individual Taxpayer Identification Number (ITIN), your business address, and the date you started or plan to start your business. You also need to know your business structure — whether you are a sole proprietor, partnership, S corporation, C corporation, LLC, nonprofit, or another type. The online tool walks you through each question and tells you what information to enter.

After you receive your number online, the IRS mails you a formal confirmation letter within two weeks. Keep that letter for your records. You can start using your Tax ID immediately, even before the letter arrives.

Getting a Tax ID by Mail

If you cannot use the online tool — for example, if you do not have internet access or your business structure is not listed in the online system — you can apply by mail using Form SS-4 (Application for Employer Identification Number). You fill out the form, mail it to the IRS address listed in the form instructions, and wait one to two weeks for your Tax ID to arrive by mail.

Form SS-4 asks for your name, business name, business address, Social Security number or ITIN, the date you started your business, and your business structure. The form is free and available on irs.gov. You do not need to sign it, but you do need to include your signature and date on the form before mailing.

Mail your completed Form SS-4 to the IRS service center that serves your state. The form itself lists the correct address in the instructions. Processing by mail is slower than online, so use this method only if the online tool is not an option for you.

Getting a Tax ID by Phone

You can also call the IRS Business and Specialty Tax Line at 1-800-829-4933 to request a Tax ID over the phone. The line is open Monday through Friday, 7 a.m. to 10 p.m. Eastern time. When you call, have your Social Security number or ITIN, business address, and business start date ready.

The IRS representative will ask you the same questions as the online form and will give you your Tax ID number over the phone. They will also mail you a confirmation letter. Phone lines can have long wait times, especially during tax season (January through April), so plan for a call that may take 30 minutes or more.

What You Need Before You Apply

Gather these documents and information before you start your application, regardless of which method you use:

Your Social Security number or Individual Taxpayer Identification Number (ITIN)
Your legal business name (the name you will use on tax forms)
Your business address (a physical street address; a PO box does not work)
The date you started your business or the date you plan to start
Your business structure (sole proprietor, LLC, corporation, partnership, nonprofit, etc.)
The type of business you operate (retail, consulting, manufacturing, etc.)

If you are applying on behalf of a business you do not own — for example, if you are a representative or manager — you will also need to provide the owner's name and Social Security number or ITIN.

After You Receive Your Tax ID

Once you have your Tax ID, use it on all business tax forms, including your annual income tax return, payroll tax forms, and sales tax returns. You also use it when opening a business bank account, applying for business credit, and hiring employees. The IRS will use your Tax ID to track all tax filings and payments related to your business.

Keep your Tax ID number and confirmation letter in a safe place. You will need to reference this number throughout the life of your business. If you lose your confirmation letter, you can request a new one from the IRS by calling 1-800-829-4933 or by visiting your local IRS office.

If your business closes or you no longer need the Tax ID, you do not have to formally cancel it. However, if you stop operating and file your final tax return, you should note that on the return so the IRS knows the business is no longer active.

Frequently Asked Questions

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

If you are a sole proprietor with no employees, you can use your Social Security number on your tax return instead of a Tax ID. However, many sole proprietors get a Tax ID anyway to keep their business and personal finances separate and to protect their Social Security number from being shared with vendors and clients.

How long does it take to get a Tax ID?

Online applications are processed immediately, and you receive your number on screen. By mail, it takes one to two weeks. By phone, you get your number during the call, but the confirmation letter arrives by mail within two weeks.

What if I applied online but did not receive my confirmation letter?

The IRS mails confirmation letters within two weeks of your online application. If you do not receive it after three weeks, call the IRS Business and Specialty Tax Line at 1-800-829-4933 to request a replacement letter or to confirm your number was issued.

Do I need a Tax ID if I am a freelancer or independent contractor?

You can report freelance income on your personal tax return using your Social Security number. A Tax ID is optional for freelancers without employees, but many use one to separate business and personal finances and to avoid sharing their Social Security number with clients.

Can I change my Tax ID if I change my business structure?

If you change your business structure — for example, from a sole proprietorship to an LLC — you typically need a new Tax ID. Contact the IRS or a tax professional to confirm whether your specific change requires a new number.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.