EIN for Sole Proprietorship: When You Need One and How to Apply

An EIN for a sole proprietorship is free from the IRS, takes about ten minutes to get online, and is only legally required in a few situations: if you hire employees, run a Keogh retirement plan, owe federal excise tax, or pay a household worker $3,000 or more in cash wages in 2026.¹ Outside those triggers you can use your Social Security Number, but most sole proprietors apply anyway so their SSN doesn’t end up on every W-9 they hand to a client.

When the IRS Requires You to Have One

Four situations make an EIN mandatory for a sole proprietor. Hiring employees is the most common, because Forms 940 and 941 and every W-2 you issue require one. Operating a Keogh plan requires one. Filing federal excise tax returns requires one. And paying a nanny, housekeeper, or other household worker $3,000 or more in cash wages during 2026 triggers Social Security and Medicare tax obligations that you can’t report without an EIN.¹

Why Most Sole Proprietors Get One Anyway

Banks routinely ask for an EIN before they’ll open a business checking account. Any client who pays you more than $600 in a year needs your taxpayer ID to file a 1099-NEC, and putting an EIN on your W-9 instead of your SSN reduces your identity theft exposure. Some state and local licensing offices also want an EIN on permit applications regardless of what federal law requires.

What to Have Ready Before You Apply

The online application can’t be saved partway through and times out after 15 minutes of inactivity, so gather everything first.²³

Have these ready:

Your legal name and SSN or ITIN, exactly as they appear on the card or letter.
Your business name, including any DBA or trade name.
Your business address (physical location, plus mailing address if different).
A short description of what the business does — something like “freelance graphic design” or “residential plumbing.”
The date you started or acquired the business, and your reason for applying (for example, “Started New Business” or “Hired Employees”).

Select “Sole Proprietor” as the entity type even if you operate under a DBA. A DBA doesn’t change your legal structure. If you’ve formed an LLC through your state, that’s a different entity type, and the IRS wants the state formation done before you apply for the entity’s EIN.²

How to Apply Online

The IRS online EIN application is the fastest route for anyone with a U.S. address. You answer a series of questions from the information you gathered, and if the application validates, your EIN appears on the final confirmation screen. Print that page immediately; it’s your initial proof of the assigned number.

The online tool runs Monday through Friday from 6:00 a.m. to 1:00 a.m. Eastern, Saturdays from 6:00 a.m. to 9:00 p.m., and Sundays from 6:00 p.m. to midnight.² The IRS limits you to one EIN per responsible party per day.⁴

The entire process is free. The IRS specifically warns about third-party sites that charge for EIN applications; there’s no reason to pay anyone for this.²

If You Can’t Apply Online

Without a principal place of business in the United States, or if the online system doesn’t work for you, submit Form SS-4 by fax or by mail. Faxed applications are processed in about four business days; mailed applications take four to five weeks.⁴ International applicants outside the United States can also call the IRS at 267-941-1000 during business hours; that dedicated line handles EIN applications over the phone.

However you apply, the IRS mails an official confirmation called the CP 575 Notice within four to six weeks. That letter is your permanent proof the EIN was assigned to your business. Banks, licensing agencies, and payroll providers ask to see it, so store it with your other tax records.

Where Your EIN Goes Once You Have It

The number goes everywhere your SSN used to go in a business context: on Schedule C when you file Form 1040, on W-9s you provide to clients, and on any employment or excise tax returns. It’s also what your bank uses to open a dedicated business account.

Your EIN doesn’t expire. It stays with you even if you change your business name, move, or open additional locations.⁵

When You Do Need a New EIN

You need a brand-new EIN when the business structure itself changes. Incorporating, forming a partnership, or declaring bankruptcy each requires a fresh number.⁵

Single-member LLCs catch people off guard. If you form an LLC that the IRS treats as a disregarded entity (you report income on your personal Schedule C), you generally don’t need a separate EIN for the LLC; your existing sole proprietor EIN or SSN works. The moment that LLC has employees or owes excise tax, though, it needs its own EIN.⁶ Changing your business name, changing your address, or owning multiple businesses don’t trigger a new number — those are administrative updates.⁵

Finding an EIN You’ve Lost

Check the CP 575 confirmation notice first, then prior business tax returns, then the bank where your business account is held, and any state or local agency you’ve applied to for a license. If none of those turn it up, call the IRS Business and Specialty Tax Line at 800-829-4933, Monday through Friday from 7:00 a.m. to 7:00 p.m. local time. They’ll verify your identity and read the number to you.⁷

1
Internal Revenue Service. 2026 Publication 926 – Household Employer’s Tax Guide
2
Internal Revenue Service. Get an Employer Identification Number
3
Internal Revenue Service. Instructions for Form SS-4 – Application for Employer Identification NumberResponsible Parties and Nominees
4
Internal Revenue Service. Instructions for Form SS-4 – Application for Employer Identification Number
5
Internal Revenue Service. When to Get a New EIN
6
Internal Revenue Service. Single Member Limited Liability Companies
7
Internal Revenue Service. Employer Identification Number