Do Sole Proprietors and Single-Member LLCs Need an EIN?

Sole proprietors and single-member LLC owners don’t automatically need an Employer Identification Number. The IRS only requires one if you hire employees, owe federal excise taxes, or set up a retirement plan such as a solo 401(k). Outside those triggers, you can generally use your Social Security number for federal tax purposes. Most owners still get an EIN voluntarily because banks want one for a business account and it keeps your SSN off client paperwork. The application is free and takes about ten minutes online.

When the IRS Requires an EIN

Federal rules identify a short list of situations where a sole proprietor or single-member LLC must have its own EIN rather than relying on the owner’s SSN.1Internal Revenue Service. Get an Employer Identification Number

If none of those apply, the IRS does not require a sole proprietor to obtain an EIN. A single-member LLC without employees or excise tax duties can also use the owner’s SSN for income tax filings.4GovInfo. 26 CFR 301.6109-1 – Identifying Numbers

The Single-Member LLC Wrinkle

Single-member LLCs face a rule that trips up a lot of owners. For income tax, the IRS treats the LLC as a “disregarded entity,” so business income flows to your personal return on Schedule C. But for employment taxes and certain excise taxes, the LLC is treated as a separate entity. If your single-member LLC has employees, the LLC itself needs an EIN and must use that number on employment tax filings — not your personal SSN.5Internal Revenue Service. Single-Member Limited Liability Companies

When an EIN Is Optional but Worth Getting

Even when the IRS doesn’t require one, many owners get an EIN for practical reasons.

Banking is the biggest driver. Federal rules require institutions to collect a taxpayer identification number before opening any account, and while your SSN technically qualifies, most banks want an EIN before they’ll open a business checking account or issue a business credit card.6Federal Deposit Insurance Corporation. Collecting Identifying Information Required Under the Customer Identification Program Rule

Privacy is another. Your SSN is the key to your personal credit, tax filings, and financial identity. Every W-9 you hand a client and every vendor form you fill out is another place it can appear. An EIN lets you handle business paperwork without spreading your SSN around.

Then there’s business credit. Credit bureaus track accounts tied to an EIN, and a business credit file built over time can help you qualify for larger credit lines and financing that doesn’t lean on your personal score.

What to Gather Before Applying

The IRS uses Form SS-4 as the basis for every EIN application. Have this ready before you start:

  • Your legal name (for a sole proprietorship) or the LLC’s registered name as filed with the state.
  • Any trade name or DBA the business uses.
  • A physical mailing address that becomes the address of record.
  • The responsible party — one real person who owns or controls the entity and its funds. For sole proprietors and single-member LLCs, that’s almost always the owner. It can’t be another business entity.7Internal Revenue Service. Instructions for Form SS-4
  • The responsible party’s SSN or ITIN.8Internal Revenue Service. Responsible Parties and Nominees
  • Your reason for applying — new business, hiring employees, banking, or compliance.

The online system doesn’t let you save your progress, so drafting Form SS-4 first is worth the five minutes.

How to Apply

Online

The IRS online application is free and issues your EIN immediately when you finish. Availability, all Eastern time:

  • Monday through Friday, 6:00 a.m. to 1:00 a.m. the next day
  • Saturday, 6:00 a.m. to 9:00 p.m.
  • Sunday, 6:00 p.m. to midnight

You have to finish in one sitting. The session expires after 15 minutes of inactivity, and there’s no save-and-return option. The IRS also limits you to one EIN per responsible party per day across all application methods, so if you’re forming multiple entities, plan for separate days.7Internal Revenue Service. Instructions for Form SS-4

When you finish, the system displays a confirmation notice with your new EIN. Print or download it right then. The IRS also mails a formal confirmation letter (CP 575), but it’s issued only once and the IRS will not generate a duplicate.

Fax and Mail

If you can’t use the online system, fax a completed Form SS-4 to the IRS EIN Operation in Cincinnati. Faxed applications generally produce an EIN within four business days. Mailed applications go to the same office and typically take four to five weeks.9Internal Revenue Service. Where to File Your Taxes for Form SS-4

International Applicants

The online system requires the responsible party to have a U.S. SSN or ITIN, which locks out many foreign owners. If you have no legal residence or principal place of business in the United States, you can apply by phone at 267-941-1099 (not toll-free), Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern time. The caller must be authorized to receive the EIN and answer questions about the SS-4. If the responsible party has no SSN or ITIN, enter “foreign” on line 7b of the form.7Internal Revenue Service. Instructions for Form SS-4 Phone applications are only for international applicants; domestic applicants must use online, fax, or mail.

When You Need a New EIN

An EIN doesn’t always carry over through business changes.

A sole proprietor needs a new EIN if they incorporate, form a partnership, or file for bankruptcy. A single-member LLC owner needs a new one if they dissolve the LLC and form a new corporation or partnership, or if the LLC begins owing employment or excise taxes for the first time.10Internal Revenue Service. When to Get a New EIN

You do not need a new EIN just because you change your business name or move. And if you’re a sole proprietor who forms a single-member LLC without electing corporate tax treatment, and you have no employees or excise tax obligations, you can keep the EIN you already had.10Internal Revenue Service. When to Get a New EIN

EINs can’t be transferred. If you sell the business, the buyer has to apply for their own.

Reporting Changes to the IRS

If your responsible party changes, or the business address changes, the IRS requires you to file Form 8822-B within 60 days. This is mandatory for any entity with an EIN.11Internal Revenue Service. Form 8822-B, Change of Address or Responsible Party – Business Missing the window doesn’t trigger an automatic fine, but if the IRS sends notices to the wrong address, you may not learn about a compliance issue until penalties have already piled up.

Don’t Pay for Something That’s Free

The IRS doesn’t charge any fee for an EIN, whether you apply online, by fax, by phone, or by mail. Third-party sites mimic the look of IRS pages and charge up to $300 for filling out the same free form. The FTC has warned operators of these sites, noting that some use IRS logos, similar color schemes, and even “IRS” in their domain names to suggest government affiliation.12Federal Trade Commission. FTC Warns Operators of Websites that Charge for an Employer Identification Number If the URL doesn’t end in .gov, it’s not the IRS.

Penalties for Filing With the Wrong Number

If you’re required to have an EIN and you file information returns with no number or the wrong one, the IRS assesses penalties per return. For 2026:

  • Up to 30 days late: $60 per return
  • 31 days late through August 1: $130 per return
  • After August 1 or not filed at all: $340 per return
  • Intentional disregard: $680 per return

These apply to each information return and each payee statement separately, so an employer with multiple W-2s filed incorrectly can rack up costs quickly.13Internal Revenue Service. Information Return Penalties Getting an EIN before you need one costs nothing. Not having one when you do can get expensive.