How to Fill Out an EIN Application for Your LLC

Filling out an EIN application for your LLC means completing IRS Form SS-4, which most owners do through the IRS’s free online interview in about ten minutes. The tool asks the same questions as the paper form but presents them one at a time and issues your nine-digit Employer Identification Number at the end of the session.¹ The work is mostly preparation: knowing your LLC’s tax classification, naming a responsible party, and having the right details on hand before you open the application.

What to Have Ready Before You Start

Gather these details first so you’re not hunting for them mid-application:

Your LLC’s legal name exactly as filed with the state, plus any trade name or DBA if you use one.
Both a mailing address and a physical address. The physical address can’t be a P.O. box.
The responsible party’s full legal name and SSN or ITIN. The responsible party is the individual who owns or controls the LLC’s funds and assets.²
The number of LLC members.
Your reason for applying. Common choices are starting a new business, hiring employees, or opening a business bank account.
The date your LLC began or will begin operations.
The closing month of your accounting year. For most new LLCs this is December.
The highest number of employees you expect in the next 12 months, split into agricultural, household, and other categories. Enter zero if you don’t plan to hire.³

One thing to sort out before you apply: whether your LLC actually needs its own EIN. A multi-member LLC does, because the IRS treats it as a partnership by default. An LLC that elects to be taxed as a corporation does too. A single-member LLC with no employees and no excise tax liability can technically use the owner’s SSN, but most owners still get an EIN because banks require one to open a business account and using your SSN with every client or vendor creates identity-theft risk.⁴ The IRS lets you request an EIN for banking or state tax reasons even when federal law doesn’t force it.¹

Working Through Form SS-4

Whether you file online or on paper, the questions track the same lines. A few are worth walking through carefully because they’re where LLC applicants stumble.

Lines 1 Through 6: Names and Addresses

Line 1 wants your LLC’s legal name exactly as it appears on your state filing. Don’t abbreviate “LLC” to “L.L.C.” unless your formation documents read that way. Line 2 is only for a trade name that differs from the legal name; otherwise leave it blank. Lines 4a and 4b capture your mailing address, lines 5a and 5b your physical location if it’s different, and line 6 the county and state of your principal business.³

Lines 7a and 7b: The Responsible Party

Enter the full legal name of the individual who controls the LLC’s funds and assets on line 7a and their SSN or ITIN on line 7b. For a single-member LLC this is normally the sole owner. For a multi-member LLC it’s the member or manager with direct control over the entity’s finances. The IRS requires one individual here. You can’t list the LLC itself, and you can’t leave the line blank.²

Lines 8a Through 9a: LLC Status and Tax Classification

Line 8a asks whether the entity is an LLC. Check “Yes.” Line 8b asks how many members it has. If a married couple in a community property state owns the LLC and chooses to treat it as a disregarded entity, enter “1.”⁵

Line 9a is the one that catches most new LLC owners. It asks for the “type of entity,” and LLC isn’t a checkbox. The IRS wants to know how your LLC will be taxed, not its state-law structure. Pick based on your situation:

Multi-member LLC accepting default classification: check “Partnership.”
Single-member LLC (disregarded entity): check “Other” and write “disregarded entity.”
LLC electing corporate taxation: check “Corporation” and enter the form number you’ll file, which is Form 1120 for a C-corp or Form 1120-S for an S-corp.³

Lines 10 Through 17: Reason, Dates, and Activity

Line 10 asks why you’re applying. Check only one box. “Started new business” fits a brand-new LLC; “Banking purpose” fits when you only need the number to open an account. Line 11 is your business start date or the date you acquired the business. Line 12 is the closing month of your accounting year.

Lines 13 through 15 deal with employees. Enter the highest number of employees you expect in the next 12 months on line 13, split into agricultural, household, and other. If you do expect employees but your annual employment tax liability will be $1,000 or less, line 14 lets you request to file Form 944 annually instead of quarterly Form 941 returns. Lines 16 and 17 ask about the LLC’s principal activity and the products or services it provides.³

Third-Party Designee and Signature

If you want an attorney, CPA, or enrolled agent to submit the application for you, fill in the third-party designee section. The designee can receive the EIN and answer IRS questions about the form, but that authority ends once the EIN is assigned. If the designee’s address or phone number matches the LLC’s, you can’t use the online tool and will need to fax or mail the form instead. The form must be signed by a member or authorized officer of the LLC who has knowledge of its affairs.⁵

How to Submit the Application

Use only one method. Filing through more than one channel can produce duplicate EINs, which is a headache to unwind later.

Online

The fastest route for domestic applicants. The responsible party needs a valid SSN, EIN, or ITIN, and the LLC must have its principal place of business in the United States or a U.S. territory.⁵ You get the EIN at the end of the session and can view, print, and save the assignment notice on the spot. The tool runs Monday through Friday from 6:00 a.m. to 1:00 a.m. Eastern, Saturday from 6:00 a.m. to 9:00 p.m., and Sunday from 6:00 p.m. to midnight.⁶

Fax

Complete the paper Form SS-4 and fax it to 855-641-6935 for LLCs in any of the 50 states or Washington, D.C.⁷ Put a return fax number on the form, and the IRS will fax the EIN back in about four business days.³

Mail

Send the completed form to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999.⁷ Processing runs about four to five weeks, and the IRS mails the EIN to your LLC’s address. If you’re trying to open a bank account or onboard employees soon, this is a poor fit.³

Whichever method you pick, the IRS issues one EIN per responsible party per day. If you’re forming several LLCs, space the applications across different days.³

The Application Is Free

The IRS charges nothing for an EIN. Third-party sites styled to look like IRS pages charge anywhere from $50 to several hundred dollars to fill out the same free form for you. The IRS is direct about it: you never have to pay for an EIN.⁶ Confirm the URL begins with irs.gov before entering any information.

After You Get Your EIN

Online applicants leave with the number in hand. Print or save the assignment notice before closing the browser. The IRS also mails a formal CP 575 notice roughly eight to ten weeks later, which serves as your official proof of the EIN assignment. Keep it filed away, since banks and state agencies sometimes ask to see it.

Fax applicants get the EIN by return fax within about four business days. Mail applicants receive theirs in about four weeks. If yours hasn’t arrived within the expected window, call the IRS Business and Specialty Tax Line at 800-829-4933, Monday through Friday, 7:00 a.m. to 7:00 p.m. local time.¹

When You Don’t Need a New EIN Later

Once assigned, an EIN is permanent. The IRS never reuses or reassigns it, and most routine changes don’t require applying again. You keep your existing number if you rename the LLC, move to a new address, convert a partnership to an LLC still taxed as a partnership, or change your tax election from partnership to corporation or S-corp.⁴

You do need a new EIN if you dissolve the LLC and form a new corporation or partnership in its place, or if your single-member LLC now has to file employment or excise tax returns for the first time.⁴ Check the IRS’s reference page on this before applying again so you don’t end up managing duplicate numbers.

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Internal Revenue Service. Employer Identification Number
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Internal Revenue Service. Responsible Parties and Nominees
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Internal Revenue Service. Instructions for Form SS-4 – Application for Employer Identification Number
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Internal Revenue Service. When to Get a New EIN
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Internal Revenue Service. Instructions for Form SS-4 (12/2025)
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Internal Revenue Service. Get an Employer Identification Number
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Internal Revenue Service. Where to File Your Taxes for Form SS-4