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 businesses, nonprofits, trusts, and certain individuals. It works like a Social Security number does for people, but for tax purposes tied to a business entity or organization.

You need an EIN if you operate a business as a sole proprietor with employees, run a partnership, own an LLC or corporation, operate a nonprofit, manage a trust or estate, or hire household workers. If you are a sole proprietor with no employees and no business structure, you can use your Social Security number instead — but many people get an EIN anyway to keep business and personal finances separate.

The IRS does not charge a fee for an EIN. The application itself is free, though you may pay a tax professional or accountant to help you file it.

Key Takeaways

  • You can obtain an EIN online through the IRS website in minutes, by phone during business hours, by mail, or through a tax professional — online is fastest.
  • The IRS issues your EIN immediately when you apply online; by phone you receive it the same day; by mail it takes two to four weeks.
  • You will need your Social Security number or Individual Taxpayer Identification Number, your business structure type, and the business start date to apply.
  • Once issued, an EIN does not expire and you do not need to renew it, though you must update the IRS if your business structure or ownership changes.

Applying Online Through the IRS Website

The fastest way to get an EIN is through the IRS online application at irs.gov/ein. The form takes about 10 minutes to complete. You will need your Social Security number or ITIN, the legal name of your business, the business address, the type of business structure (sole proprietor, partnership, S-corp, C-corp, LLC, nonprofit, trust, or other), and the date you started or plan to start the business.

When you submit the form online, the IRS issues your EIN immediately. You can print a confirmation page with your number on it right away, and you can also retrieve it later by logging back into the IRS system with your information. The IRS will mail you an official letter with your EIN within two weeks, but you can begin using the number from the confirmation page as soon as you receive it.

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

Applying by Phone or Mail

If you cannot or prefer not to apply online, you can call the IRS Business and Specialty Tax Line at 1-800-829-4933. A representative will walk you through the questions and issue your EIN over the phone the same day. Have the same information ready as you would for the online form. The phone line is open Monday through Friday, 7 a.m. to 10 p.m. Eastern Time.

You can also mail Form SS-4 (Application for Employer Identification Number) to the IRS. Download the form from irs.gov, fill it out by hand or type it, and mail it to the address listed on the form — the address depends on which state your business is located in. Processing by mail takes two to four weeks. You will receive your EIN by mail.

If you use a tax professional, accountant, or attorney to file your EIN, they can submit it online or by phone on your behalf. They will need a power of attorney form signed by you, which they can provide.

What Information You Will Need to Provide

Regardless of which method you choose, have these details ready before you start:

  • Your Social Security number or Individual Taxpayer Identification Number (ITIN)
  • The legal name of your business exactly as it appears on your business registration or formation documents
  • The business mailing address and physical location address (they can be the same)
  • The type of business structure: sole proprietor, partnership, S-corporation, C-corporation, LLC, nonprofit, trust, estate, or other
  • The date you started the business or the date you plan to start it
  • The primary business activity or industry (for example, "retail clothing sales" or "consulting services")
  • The name and Social Security number of the principal owner or officer

If you are applying on behalf of someone else or a business you do not own, you will also need to provide your relationship to the business and your own Social Security number.

After You Receive Your EIN

Once the IRS issues your EIN, it does not expire. You do not need to renew it or reapply unless your business structure changes — for example, if you convert from a sole proprietorship to an LLC, or if your business is acquired or merges with another. If any of those changes happen, you may need a new EIN; contact the IRS or a tax professional to confirm.

You will use your EIN on tax returns, business licenses, bank account applications, payroll documents, and any correspondence with the IRS. Keep your EIN and the IRS letter in a safe place. If you lose the letter, you can retrieve your EIN by calling the IRS or logging into your online account.

If you hired a tax professional to obtain your EIN, ask them for a copy of the confirmation or the official letter. You will need it to open a business bank account and to file your first tax return.

Special Situations: Nonprofits, Trusts, and Household Employers

Nonprofits follow the same process as other businesses but must select "nonprofit organization" as the business structure. You will also need the date your nonprofit was formed or incorporated. Some states require a nonprofit to be registered before applying for an EIN; check your state's nonprofit registration rules first.

If you are managing a trust or estate, you will need the trust or estate name, the date it was created, and the name and Social Security number of the trustee or executor. Trusts and estates have their own EIN separate from the individuals involved.

If you hire household workers — a nanny, housekeeper, gardener, or other household employee — you need an EIN to report their wages and taxes. You can apply for an EIN even if you are a sole proprietor with no other business. The process is the same; select "household employer" as your business structure.

Frequently Asked Questions

How long does it take to get an EIN?

Online is fastest: you receive your EIN immediately and can print it on the spot. By phone, you get it the same day. By mail, allow two to four weeks. If you use a tax professional, timing depends on when they submit and how quickly the IRS processes it, but usually one to two weeks.

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

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

What if I applied for an EIN but never received the letter?

Call the IRS at 1-800-829-4933 with your business information and they will look up your EIN. You can also log into the IRS online system if you applied there and retrieve your number from your account. You do not need the physical letter to use your EIN, though having it is helpful for your records.

Do I need a separate EIN for each business I own?

Yes. Each separate business entity — whether it is a different LLC, corporation, or partnership — needs its own EIN. If you own multiple businesses under the same legal entity, they share one EIN. A tax professional can help you determine whether your situation requires one or multiple EINs.

What happens if I apply for an EIN and then decide not to start the business?

Nothing. An EIN that is issued but never used does not cause problems. You do not need to cancel it or notify the IRS. If you later decide to start a business, you can use the EIN you already have.