What Is an EIN? Who Needs One and How to Apply

To apply for an EIN, go to IRS.gov and use the online EIN assistant: it’s free, takes a few minutes, and issues your nine-digit Employer Identification Number as soon as you finish the questionnaire.¹ If you can’t apply online, you can submit Form SS-4 by fax or mail instead, and international applicants without a U.S. business location can apply by phone.

What To Have Ready Before You Apply

Gather this information before you open the application. Having it in front of you means you can finish the online session in a single sitting, which matters because the IRS tool doesn’t save progress.

The legal name of your entity
Its mailing address and physical address
The type of entity (corporation, LLC, partnership, sole proprietorship, estate, trust, nonprofit, and so on)
Your reason for needing the EIN, such as starting a new business or hiring employees
The name and taxpayer identification number of the “responsible party,” typically the owner or a principal officer, who must provide a Social Security number or Individual Taxpayer Identification Number²

Applying Online

The IRS online EIN assistant is the fastest way to get a number. You answer a short set of questions about your entity and receive the EIN on screen at the end of the session. Save or print the confirmation notice (CP 575) right away, because you’ll want it for your bank, your records, and any future request to verify the number.

The tool operates on a schedule. It’s available Monday through Friday from 6:00 a.m. to 1:00 a.m. the next day, Saturdays from 6:00 a.m. to 9:00 p.m., and Sundays from 6:00 p.m. to midnight, all Eastern time. One important limit: you can apply for only one EIN per responsible party per day.¹ If you’re setting up multiple entities, plan on spreading the applications across days.

Applying by Fax or Mail

If you’d rather work from paper, download Form SS-4 from IRS.gov, complete it, and send it in. Fax is much faster than mail. A faxed SS-4 that includes a return fax number typically produces an EIN within four business days. A mailed application takes about four weeks.³

Applying From Outside the United States

If your entity has no legal residence, principal place of business, or principal office in the United States or its territories, the online tool won’t accept your application. You have three options instead.

You can call the IRS at 267-941-1099 (not toll-free), Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern time, and receive an EIN over the phone. You can fax Form SS-4 to 304-707-9471. Or you can mail it to the IRS EIN International Operation office in Cincinnati. If the responsible party has no SSN or ITIN, enter “foreign” or “N/A” on line 7b of Form SS-4.⁴

Don’t Pay for an EIN

The IRS issues EINs at no charge. Any website asking for your credit card to “file” an EIN application is charging you for a service the IRS provides free, and the FTC has warned operators of sites that charge up to $300 for exactly that.¹ Go directly to IRS.gov.

Who Actually Needs an EIN

Some entities are required to have an EIN. Others benefit from having one but can operate without. The IRS requires an EIN if any of the following applies:⁵

You have employees (even one), because you’ll need the number to report and deposit employment taxes⁶
Your business is a corporation or partnership, regardless of whether it has employees
You run a multi-member LLC, which the IRS treats as a partnership by default
You operate a tax-exempt organization, which needs an EIN both to operate and to apply for exemption
You’re administering an estate or most trusts (certain grantor-owned revocable trusts are an exception)
You withhold tax on non-resident alien income
You file excise tax returns for alcohol, tobacco, firearms, or similar

A sole proprietor with no employees, no excise tax obligations, and no retirement plan can technically operate using only a Social Security number. Many still apply for an EIN because banks, vendors, and clients ask for one, and using it on W-9s and invoices keeps a personal SSN off business paperwork.

What To Do After You Have Your EIN

Keep the CP 575 confirmation notice with your permanent business records. You’ll put the EIN on every federal return, deposit, and piece of correspondence you send the IRS, and you’ll need it to open a business bank account and apply for most business licenses.⁷

When your business address, location, or responsible party changes, file Form 8822-B with the IRS. Changes in the responsible party must be reported within 60 days. Missing the deadline doesn’t trigger a penalty on its own, but if the IRS doesn’t have your current address, you may not receive notices of deficiency or demand for payment, and any penalties and interest keep accruing.⁸

If you later misplace the number, check the CP 575, a previously filed tax return, or your business bank. If none of those work, call the IRS Business and Specialty Tax Line at (800) 829-4933. After verifying your identity, an agent can look up the EIN and send a confirmation letter (Letter 147C).⁵

1
Internal Revenue Service. Get an Employer Identification Number
2
Internal Revenue Service. Instructions for Form SS-4 – Application for Employer Identification Number
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Taxpayer Advocate Service. Getting an EIN
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Internal Revenue Service. Instructions for Form SS-4 (12/2025)
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Internal Revenue Service. Employer Identification Number
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Internal Revenue Service. Businesses With Employees
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Internal Revenue Service. Publication 1635 – Understanding Your EIN
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Internal Revenue Service. Form 8822-B – Change of Address or Responsible Party – Business