How to Fill Out the SS4 Form for an LLC?
The SS-4 Form is how you apply for an Employer Identification Number (EIN) with the IRS — and getting it right the first time saves you a real headache.
I've helped a lot of first-time founders through LLC formation, and the EIN application is one of those steps that looks simple but trips people up more than it should.
Below, our team walks you through exactly how to fill out Form SS-4 for an LLC — line by line, no guesswork.
Quick Summary:
- To fill out Form SS-4 for an LLC, you'll need your business's legal name, mailing address, and entity type — get these wrong and the IRS will kick it back.
- Once completed, you can submit the form by mail, fax, or online. Online is fastest — you'll typically get your EIN the same day.
- According to U.S. Census Bureau data, business applications hit 5.4 million in 2021 — which means a lot of new entities need an EIN, and a lot of SS-4 forms are being filed with errors.
- Single-member LLCs aren't required to get an EIN, but I'd recommend getting one anyway. You'll need it to open a business bank account, hire employees, or apply for financing.
Fill out the SS4 Form for LLC
The IRS recorded 450,078 EIN applications in January 2024 alone, according to the U.S. Census Bureau [1]. That's a lot of businesses filing Form SS-4 — and plenty of room for mistakes.
The form itself isn't long, but each field matters. Here's what you'll need to fill in.
Line 1. The legal name of the entity (or individual) for whom the Employer Identification Number is being requested
Make sure the name matches exactly what's on your LLC Articles of Organization. Even a small mismatch can cause delays.
Line 2. Trade name of the business
Fill in the LLC business name or "doing business as" (DBA) name here if your LLC does business under a different name than its legal name.
Line 3. Executor, administrator, trustee, “care of” name
If you're using a third party to file the EIN on the company's behalf, enter their full legal name here. We've done this for clients who hired a registered agent or attorney to handle the filing.
Lines 4a–b. Mailing address
Enter the address where the IRS should send mail. In most cases, this should match the address you use on the company's tax returns.
Lines 5a–b. Street address
If the company's physical location differs from the mailing address in lines 4a–b, enter it here. If they're the same, leave this section blank.
Line 6. County and state where the principal business is located
Fill in the county and state where the business actually operates.
Lines 7a–b. Name of the responsible party
Enter the responsible party's full name — first name, middle initial, last name — along with their SSN, ITIN, or EIN.
The IRS defines the responsible party as the individual who must sign Form SS-4 [2]. Don't leave this one vague.
Lines 8a–c. Limited Liability Company (LLC) information
For LLC filers, you'll need to list the members and provide additional details about the company's structure. I've seen people skip this section — don't.
Line 9a. Type of business entity
Check the one box that matches your entity type: LLC, Sole Proprietorship, Partnership, S Corporation, or Personal Service Corporation.
One thing worth knowing: filling out Form SS-4 doesn't count as a tax classification election for your LLC. That's a separate step.
Line 10. Reason for applying
Select the primary reason you're applying for an EIN — opening a business bank account, hiring employees, applying for a loan, and so on.
Read our article for more information on how to get a Tax ID number for an LLC.
Started Single Member LLC, Confused on Form SS-4 Line 9a
If you have a single-member LLC, select "Sole Proprietor" on line 9a. By default, the IRS treats single-member LLCs as "disregarded entities" — which means all income and expenses flow through to your personal tax return on Schedule C, the same as a sole proprietorship.
The S-Corp question confuses a lot of people here. LLCs can elect different tax treatment by filing additional forms, but unless you've made that election, the default is sole proprietorship. Stick with that unless your tax situation specifically calls for something else.
What is an EIN?
An EIN is a nine-digit tax ID number the IRS assigns to businesses for LLC tax filing and reporting purposes.
Business applications hit 5.4 million in 2021 — a record at the time — which tells you how many new entities are out there needing one. You'll use your EIN to open a business bank account, pay employees, file taxes, and apply for financing. Without it, you're stuck.
If you don't have one yet, you get it by filing IRS Form SS-4 [3].
"For patriots like me, paying taxes gives a feeling of responsibility, of being part of the fabric of our country, of contributing to the common good."
- Joyce Marcel, Award-Winning Vermont Journalist
FAQs
Do Both Members of an LLC Need an EIN?
Both members of an LLC does not need an EIN since the number is assigned to a business and not the individual.
What Is the Difference Between a Federal Tax Identification Number and a Social Security Number?
The main difference between a Federal Tax Identification Number and a Social Security Number is their purpose. An EIN, obtained through Form SS-4, identifies a business for tax purposes, while a Social Security Number is used for personal tax identification.
When to File Form SS4?
File Form SS4 4 to 5 weeks before you need the EIN.
Fill out Form SS-4 carefully and your EIN comes back fast — online applications typically process the same day. Rush it or get the details wrong, and you're looking at delays that can hold up your bank account, your hiring, and your financing.
If you're not sure which submission method to use, go online. It's the fastest option and you'll have your EIN before the end of the day.
References:
- https://www.census.gov/econ/bfs/pdf/bfs_current.pdf
- https://www.irs.gov/forms-pubs/about-form-ss-4
- https://www.irs.gov/businesses/small-businesses-self-employed/employer-id-numbers
