How to Get an EIN (and Why You Need One)

An EIN (Employer Identification Number) is a free, nine-digit number the IRS assigns to a business so it can be identified for tax purposes. Think of it as a Social Security Number for your business. The IRS also calls it a Federal Tax Identification Number. Almost every U.S. business with employees, an LLC, a corporation, or a business bank account needs one.

This is plain-English starter content. For more, see our Learn hub and business basics.

Who needs an EIN?

The IRS requires an EIN if you answer yes to any of these:

• You have employees (even one)
• Your business is a corporation or partnership
• You file employment, excise, or alcohol/tobacco/firearms tax returns
• You withhold taxes on income (other than wages) paid to a non-resident
• You have a Keogh plan or certain trusts

In practice, most banks also require an EIN to open a business checking account, even for a single-member LLC that could legally use the owner's SSN for federal taxes. So almost every serious business gets one.

Who does not strictly need one?

A sole proprietor with no employees, no excise tax, and no separate business entity can technically use their personal Social Security Number. But getting an EIN is free and takes 10 minutes, so most owners get one anyway to keep their SSN off invoices, contractor forms, and W-9s sent to clients.

Cost: zero

The IRS issues EINs for free. If a website charges you to "get" an EIN, they are charging for filling out the form on your behalf — the IRS itself never charges. Always start at irs.gov, not a third-party site that mimics it.

How to apply: the four ways

You can apply four ways. The online application is by far the fastest.

1. Online (recommended for most)

The IRS online EIN assistant issues your number immediately upon completion. Hours: typically Monday through Friday, 7 a.m. to 10 p.m. Eastern. The session is single-use and times out after 15 minutes of inactivity, so prepare your information first.

Requirements:

• The applicant ("responsible party") must have a valid SSN, ITIN, or existing EIN
• The principal business must be in the U.S. or a U.S. territory
• One EIN per responsible party per day

Apply at the IRS EIN online application.

2. Fax (Form SS-4)

Fill out Form SS-4 and fax to the IRS. The IRS faxes your EIN back, usually within four business days.

3. Mail (Form SS-4)

Same form, mailed to the IRS. Allow about four weeks. Useful as a backup; not the fastest path.

4. Phone (international applicants only)

International applicants without a U.S. SSN or ITIN can call the IRS international EIN line during business hours.

What you need before you start

Have the following ready before opening the online application:

• Legal business name — exactly as it appears on your formation documents. A typo here causes IRS letters and bank-account headaches later.
• Trade name (DBA) if different
• Business address (P.O. boxes are not accepted as the principal address)
• Responsible party's name and SSN/ITIN
• Entity type — sole proprietor, LLC, partnership, corporation, etc. See our LLC vs. sole proprietor guide.
• Reason for applying — usually "started new business"
• Date business started or acquired
• Closing month of accounting year — most small businesses choose December
• Highest number of employees expected in the next 12 months
• Principal activity — what your business actually does

After you get the EIN

The IRS issues a confirmation letter called CP 575. Save this PDF in at least two places. Banks and lenders often ask for it for years.

Use the EIN to:

• Open a business bank account
• Apply for state tax IDs and a sales tax permit (see our sales tax guide)
• Register with your state's unemployment insurance and workers' compensation systems
• Set up payroll and sign up for E-Verify and SSA Business Services Online
• File federal business tax returns

Common EIN mistakes

• Typing the legal name slightly wrong. "ABC Plumbing LLC" is not the same as "ABC Plumbing, LLC" to the IRS.
• Listing the wrong responsible party. This person must be a true principal owner with control of the business — not a bookkeeper or attorney filing on your behalf.
• Applying before forming the entity. If you plan to be an LLC, file with the state first, then apply for the EIN under the LLC name.
• Getting more than one EIN. A business should have exactly one EIN. If you have a real change (sole prop converting to LLC, ownership change), the IRS has rules for whether a new EIN is required.

A note on changes

If your business name, address, or structure changes, the IRS has specific notification procedures — sometimes a letter, sometimes a new EIN is required. The IRS Do You Need a New EIN page is the official guide.

Avoiding the lookalike "EIN service" sites

Search results for "get EIN" are full of paid services that charge $100 to $400 to file the free SS-4 on your behalf. Some are legitimate filing services. Others are misleading sites designed to look like the IRS. A few warning signs:

• The URL is not irs.gov
• They charge a fee at all (the IRS doesn't)
• They request your SSN before they confirm who they are
• They claim guaranteed approval or "priority processing" the IRS doesn't actually offer

There is nothing wrong with paying a CPA or attorney to file SS-4 as part of a broader entity setup, but you should know what you're paying for. The application itself is straightforward and free.

EIN security after you have it

Treat your EIN like a Social Security Number for your business. While not as sensitive as an SSN, criminals do use stolen EINs to file fraudulent tax returns and open lines of credit in business names. Don't post your EIN publicly, and store the CP 575 confirmation letter somewhere encrypted or password-protected. If you suspect EIN-based identity theft, the IRS Business Identity Theft page explains the response steps.

This is general info, not tax advice. For your specific situation, talk to a CPA or enrolled agent.

Tax laws and SBA programs change every year — always check the latest at IRS.gov, SBA.gov, and your state's Secretary of State website.