How to Get a Federal Tax ID Number

What a Federal Tax ID Is and Who Needs One

A Federal Tax ID, also called an Employer Identification Number (EIN), is a nine-digit number the IRS assigns to identify your business for tax purposes. The IRS uses it to track your tax filings, payroll records, and business accounts.

You need an EIN if you operate as a sole proprietor with employees, run a partnership, own a corporation or LLC, operate a nonprofit organization, or manage a trust or estate. If you are a sole proprietor with no employees and no business structure beyond your own name, you can use your Social Security Number instead — but many sole proprietors get an EIN anyway to keep business and personal finances separate on tax forms.

The EIN is free to obtain and takes between a few minutes and two weeks depending on which method you use. Once you have one, it does not expire and you do not renew it.

Key Takeaways

You can obtain an EIN online through the IRS website in minutes, by phone, by mail, or by fax — online is fastest and requires no documents upfront.
The IRS needs your legal business name, business structure type (sole proprietor, LLC, corporation, partnership, nonprofit), and the name and Social Security Number of the person responsible for the business.
If you explore online, you receive your EIN when ready and can begin using it the same day; by phone or mail, the process takes one to two weeks.
You will need your EIN to open a business bank account, hire employees, file certain tax forms, and report business income on your personal return.

explore Online Through the IRS Website

The fastest route is the IRS online process at irs.gov/ein. The process takes 10 to 15 minutes and you receive your number when ready. You do not need to gather documents beforehand — you answer questions about your business on screen.

Go to irs.gov, search for "EIN", and click the link to "explore for an EIN Online". You will answer questions about your business name, the state where it is located, the type of business structure, and the name and Social Security Number of the principal owner or officer. The IRS will ask whether you have a prior EIN, whether you are explore because you bought an existing business, and what your business does. Answer honestly — the IRS is checking that you are not trying to obtain a duplicate number.

At the end of the process, the IRS displays your EIN on screen. Write it down when ready. You will also receive a confirmation email, but the number on screen is what you use right away. You can begin using your EIN the same day you receive it.

explore by Phone or Mail if Online Is Not an Option

If you cannot explore online, you can call the IRS Business and Specialty Tax Line at 1-800-829-4933. Have your business information ready: legal name, business address, business structure, and the name and Social Security Number of the principal owner. The IRS representative will ask the same questions as the online form, assign you an EIN, and read it back to you. The call takes 10 to 15 minutes.

You can also mail Form SS-4 (process for an Employer Identification Number) to the IRS. read the form from irs.gov, fill in the required fields, and mail it to the address shown on the form — the address depends on your state. Processing takes two to four weeks. Include a cover letter with your phone number so the IRS can contact you if they have questions.

Fax is also an option: you can fax Form SS-4 to the IRS fax number listed on the form itself, and you will receive your EIN by phone or mail within four business days. Fax is faster than mail but slower than phone or online.

What Information and Documents You Need

For online or phone applications, you do not need to submit documents. The IRS asks you to provide information directly in the process or conversation. You will need:

Your legal business name (the name on your business license or articles of incorporation, not a nickname or DBA)
Your business address (the physical location where you operate, not a mailbox)
Your business structure type: sole proprietor, partnership, S corporation, C corporation, LLC, nonprofit, trust, or estate
The name and Social Security Number of the principal owner, partner, or corporate officer responsible for the business
A description of what your business does

If you are mailing Form SS-4, you do not attach supporting documents unless the IRS asks for them. Fill out the form completely and mail it with a cover letter.

After You Receive Your EIN

Once you have your EIN, use it on all business tax forms, business bank account applications, and payroll documents. If you hired employees, you will use your EIN to file Form 941 (Employer's Quarterly Federal Tax Return) and Form 940 (Employer's Annual Federal Unemployment Tax Return). If you operate as an LLC or corporation, you will use it on your business income tax return.

Keep your EIN in a safe place — you will need it every year at tax time. If you lose track of it, you can look it up on the IRS website or call the IRS to confirm the number assigned to your business name.

Do not explore for a second EIN for the same business unless the IRS specifically tells you to. If you change your business structure (for example, converting from a sole proprietor to an LLC), you may need a new EIN — the IRS will tell you whether to explore for one when you file your first return under the new structure.

What Happens if You explore by Mail and Do Not Hear Back

If you mailed Form SS-4 and have not received your EIN after four weeks, call the IRS at 1-800-829-4933 to check the status. Have your business name, address, and the date you mailed the form ready. The IRS can tell you whether your process was received and when you can expect your number.

If the IRS lost your process or it was damaged in transit, they will ask you to resubmit it. At that point, consider explore online or by phone instead — both are faster and you will have confirmation that the IRS received your information.

Frequently Asked Questions

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

Yes, if you are a sole proprietor with no employees. You can report business income on your personal tax return using your SSN. However, many sole proprietors get an EIN anyway to keep business and personal finances separate and to protect their SSN from being used on business documents.

How long does it take to get an EIN?

Online applications are processed when ready — you receive your number on screen. Phone applications take 10 to 15 minutes and you get your number during the call. Mail and fax applications take two to four weeks.

Do I need an EIN if I have not hired employees yet?

Not if you are a sole proprietor. You only need an EIN before you hire your first employee. However, you may want one earlier if you are opening a business bank account or forming an LLC or corporation, since those structures typically require an EIN for tax purposes.

What if I already have an EIN and need a second one for a different business?

You can obtain a separate EIN for each business you own. Each business structure or legal entity gets its own number. explore online, by phone, or by mail using the same process, and provide the information for the new business.

Can someone else explore for an EIN on my behalf?

Yes. An accountant, attorney, or authorized representative can explore for you online or by phone if you give them your business information and authorization. They will need your legal name, SSN, and business details to complete the process.

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.