How to Get a Tax ID Number

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 code the IRS uses to identify your business, nonprofit, or other entity for tax purposes. The IRS issues it free, and you do not pay to get one.

You need a Tax ID Number if you operate a business as a sole proprietor with employees, run a partnership, own a corporation or LLC, operate a nonprofit, 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 — but many self-employed people get a Tax ID Number anyway to keep their personal and business finances separate.

The IRS does not mail Tax ID Numbers unsolicited. You request one, and the process takes minutes to a few business days depending on how you apply.

Key Takeaways

You can get a Tax ID Number free from the IRS online, by phone, fax, or mail, and the online method gives you a number the same day.
The IRS Form SS-4 is the official application, and you fill it out the same way regardless of which method you use.
If you apply online at irs.gov/ein, you receive your number immediately and can use it right away.
Sole proprietors without employees can use their Social Security Number for taxes, but a Tax ID Number keeps business and personal finances separate.
You need your business structure type (sole proprietor, LLC, corporation, nonprofit), your business address, and the type of work you do to complete the application.

Applying Online for Immediate Issuance

The fastest way to get a Tax ID Number is to apply online at irs.gov/ein. The IRS issues your number the same day, and you can begin using it immediately. You do not need to create an account or log in — you fill out the form once and receive your number at the end.

To apply online, you need a valid Social Security Number or Individual Taxpayer Identification Number (ITIN), your business address, and information about your business structure and the type of work you do. The form takes about 10 minutes. After you submit, the IRS displays your Tax ID Number on screen and sends a confirmation by email. Write down the number and save the email — you will need it to open a business bank account and file taxes.

Online applications are open Monday through Friday, 7 a.m. to 10 p.m. Eastern Time. The system is closed on federal holidays.

Applying by Phone, Fax, or Mail

If you cannot apply online, you can request a Tax ID Number by phone, fax, or mail. Each method takes longer than the online route.

By phone: Call the IRS Business and Specialty Tax Line at 1-800-829-4933. You will speak to an IRS representative who walks you through Form SS-4 over the phone. They issue your number on the call and mail you a confirmation letter. This usually takes one to two weeks.

By fax: Complete Form SS-4 and fax it to the IRS fax number for your state (listed on the form itself). The IRS typically responds within four business days with your Tax ID Number.

By mail: Print Form SS-4, fill it out by hand or type it, and mail it to the IRS address for your state (also on the form). Processing takes two to four weeks. This is the slowest method and is best used only if you have no other option.

What Information You Need Before You Apply

Gather these details before you start your application, regardless of which method you use:

Your legal name and Social Security Number (or ITIN if you do not have an SSN)
Your business name, if different from your legal name
Your business address (a physical street address, not a P.O. box)
Your business structure: sole proprietor, partnership, S corporation, C corporation, LLC, nonprofit, trust, estate, or other
The type of business or activity you do (for example: consulting, retail sales, nonprofit education, property management)
The reason you are requesting a Tax ID Number (new business, change of ownership, bankruptcy, etc.)
Your first month of business operation (if you are just starting)

If you are applying on behalf of a business you do not own — for example, as a manager or accountant — you will also need to provide the owner's name and Social Security Number, and state your relationship to the owner.

After You Receive Your Tax ID Number

Once you have your Tax ID Number, use it on all business tax forms, bank account applications, and official documents. The IRS will mail you a confirmation letter (Form SS-4 or EIN Assignment Notice) within two to four weeks, depending on how you applied. Keep this letter in your records.

If you applied online or by phone, you received your number immediately. If you applied by fax or mail and have not heard from the IRS after the expected timeframe, call 1-800-829-4933 to confirm receipt and check the status.

A Tax ID Number does not expire and does not need to be renewed. You use the same number for the life of your business unless the business structure changes (for example, if a sole proprietorship becomes an LLC).

When You Need a New Tax ID Number

In most cases, you keep the same Tax ID Number indefinitely. However, you need to request a new one if your business structure changes — for example, if you convert a sole proprietorship to an LLC, or if a partnership dissolves and reforms with different partners. You also need a new number if you purchase an existing business and want to treat it as a new entity rather than a continuation.

If your business closes, you do not need to do anything with your Tax ID Number. Simply stop using it and report the closure on your final tax return. The IRS will deactivate it automatically.

Frequently Asked Questions

Do I need a Tax ID Number if I am self-employed with no employees?

No, you can use your Social Security Number on your tax return and business documents. However, many self-employed people request a Tax ID Number anyway to keep their personal and business finances separate, especially if they plan to hire employees later or want a business bank account.

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

Online applications at irs.gov/ein issue a number the same day. Phone applications issue a number during the call. Fax applications typically take four business days. Mail applications take two to four weeks. If you need the number immediately, apply online.

Can I use my Tax ID Number before I receive the confirmation letter?

Yes. If you applied online or by phone, you can use your Tax ID Number right away. If you applied by fax or mail, you can use it as soon as the IRS issues it (which you will learn by phone or mail). Do not wait for the confirmation letter to arrive.

What if I lose my Tax ID Number?

Your Tax ID Number does not change, so you can look it up on any previous tax return, bank statement, or business document where you used it. If you cannot find it anywhere, call the IRS at 1-800-829-4933 and they will provide it over the phone.

Is there a fee to get a Tax ID Number?

No. The IRS issues Tax ID Numbers free. If a website or service charges you to get one, you are being overcharged — you can always apply directly to the IRS at no cost.

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.