LLC Tax Guide

How to Apply for an EIN with SS-4: A Simple Guide for Single-Member LLCs

Need an Employer Identification Number for your LLC? Learn when you actually need one, how to apply using Form SS-4, and get your EIN in as little as a few minutes.

~15 min

Online application time

Instant

EIN issued online

Free

Via IRS directly

SS-4

Form required

What Is an EIN and Why Do You Need One?

An Employer Identification Number (EIN) is a nine-digit number assigned by the IRS to identify your business for tax purposes. Think of it as a Social Security Number for your business. It's formatted as XX-XXXXXXX.

Even though it's called an "Employer" Identification Number, you don't need employees to get one. Many single-member LLC owners get an EIN for reasons beyond hiring.

You NEED an EIN If You...
Have employees or plan to hire employees
Operate your LLC as a corporation or partnership for tax purposes
File employment, excise, or alcohol/tobacco/firearms tax returns
Have a Keogh plan (a retirement plan for self-employed)
Are involved with trusts, estates, non-profits, or certain other entities
You SHOULD Get an EIN If You...
Want to open a business bank account (most banks require an EIN)
Want to protect your SSN on W-9 forms
Work with clients or vendors who prefer to see an EIN
Want to build business credit separately from personal credit

What Is Form SS-4?

IRS Form SS-4, "Application for Employer Identification Number," is the form you use to apply for an EIN. Whether you apply online, by fax, by mail, or by phone, you're providing the same information that's on Form SS-4.

For online applications, you don't actually submit a paper SS-4—the online system collects the same information. However, having a completed SS-4 ready makes the online process faster since you'll have all the answers prepared.

Pro Tip: Prepare First

Before starting your online EIN application, use our SS-4 generator to fill out the form. This ensures you have all the information ready, and gives you a PDF record of what you submitted.

4 Ways to Apply for an EIN

1Online (Recommended)
Instant EIN

The fastest and easiest method. Apply directly on the IRS website or use a service likeEIN National Filing for guided assistance.

✓ Pros:

  • • EIN issued immediately
  • • Available M-F, 7am-10pm ET
  • • Free through IRS

✗ Cons:

  • • Requires SSN or ITIN
  • • Limited hours
  • • Session times out after 15 min
2Fax
4 Business Days

Complete Form SS-4 and fax it to the appropriate IRS fax number based on your state. The IRS will fax your EIN back to you.

Fax Numbers:

• (855) 641-6935 — If your principal business is in one of the 50 states or DC

3Mail
4-5 Weeks

Mail your completed Form SS-4 to the IRS. This is the slowest option but works if you can't use online or fax.

Mailing Address:

Internal Revenue Service
Attn: EIN Operation
Cincinnati, OH 45999

4Phone (International Only)
Immediate

Only available for applicants with no legal residence, principal place of business, or principal office in the U.S.

Phone Number: 267-941-1099 (Not toll-free)

Hours: 6am-11pm ET, Monday-Friday

Step-by-Step: Applying Online

Here's exactly what to expect when applying for your EIN online:

1Identify Your Entity Type

Select "Limited Liability Company (LLC)" from the list of entity types. The system will ask follow-up questions about the number of members and how the LLC is taxed.

2Answer LLC-Specific Questions

For a single-member LLC, you'll indicate:

  • • Number of members: 1
  • • State where LLC was organized
  • • Whether you elected to be taxed as a corporation (most select "No")

3Select Reason for Applying

Common reasons for single-member LLCs:

  • • "Started a new business" — Most common choice
  • • "Banking purposes" — If that's your main reason
  • • "Hired employees" — If you're getting an EIN to hire

4Enter Responsible Party Information

As the sole owner of your LLC, you are the "responsible party." Enter your full legal name, SSN (or ITIN), and title (typically "Owner" or "Member").

5Provide Business Details

Enter your LLC's information:

  • • Legal name of LLC (as registered with the state)
  • • Trade name/DBA if different
  • • Business address
  • • Mailing address (if different)
  • • County

6Describe Your Business Activity

Select the category that best describes your business (e.g., "Professional Services," "Retail," "Construction") and provide a brief description of your specific activity.

7Review and Submit

Double-check all information for accuracy. Once you submit, you'll receive your EIN immediately on screen. You can also download or print your confirmation letter (CP 575).

Get your EIN today

Apply online through the IRS (free) or use a filing service for guided help.

Form SS-4 Line-by-Line for Single-Member LLCs

If you're applying by fax or mail (or just want to prepare), here's how to complete each section of Form SS-4:

LineWhat to Enter
Line 1Legal name of your LLC (e.g., "Smith Consulting LLC")
Line 2Trade name/DBA if different from Line 1 (or leave blank)
Line 3Name of responsible party (your name as sole owner)
Line 4a-bMailing address (street, city, state, ZIP)
Line 5a-bStreet address if different from mailing address
Line 6County and state where LLC's principal business is located
Line 7aResponsible party's SSN (or ITIN)
Line 8aCheck "LLC" (Limited Liability Company)
Line 8bEnter "1" for number of LLC members
Line 8cIf organized in a foreign country, enter country name
Line 9aCheck "Started new business" or applicable reason
Line 10Date business started or acquired
Line 11Closing month of accounting year (usually December = "12")
Line 12Expected number of employees in first 12 months (can be 0)
Line 13First date wages paid (or N/A if no employees)
Line 14Check box indicating highest number of employees expected
Line 15Check if first wages include agricultural employees
Line 16Check boxes for type of taxes you'll pay (if applicable)
Line 17Principal activity description (e.g., "consulting services")
Line 18Products or services (e.g., "web development services")

Common EIN Application Mistakes

Using LLC Name for Responsible Party

The responsible party must be an individual with an SSN or ITIN—not the LLC itself. As the sole member, enter your personal name and SSN.

Selecting Wrong Entity Type

Make sure to select "LLC" not "Sole Proprietor" even if you're a single-member LLC. They're legally different entities even though they may be taxed similarly.

Not Saving Confirmation

After receiving your EIN online, immediately save or print your confirmation notice (CP 575). You can't retrieve it later from the IRS website, and you'll need proof of your EIN for banking and other purposes.

Applying Before LLC Is Formed

Your LLC must be legally formed (filed with your state) before you can apply for an EIN. The IRS may ask for your LLC's formation date.

After You Get Your EIN

Once you have your EIN, here's what to do next:

Open a Business Bank Account

Take your EIN confirmation letter to your bank to open a business checking account.

Update Your W-9

Use your EIN instead of SSN on W-9 forms for clients.

Keep Records

Store your CP 575 confirmation letter safely. You may need it for loans, contracts, or IRS correspondence.

Set Up Payroll (If Hiring)

If you're hiring employees, use your EIN to register for payroll taxes andcreate paystubs.

Frequently Asked Questions

What to do after getting your EIN