LLC Step Explainer · 2026-05-12

EIN Application for Your LLC: How to Get an Employer Identification Number (2026)

An Employer Identification Number (EIN) is a nine-digit federal tax identification number issued by the IRS to identify your LLC for tax purposes. Think of it as a Social Security number for your business. Most LLCs need an EIN to open a business bank account, hire employees, file tax returns, and establish credit. While single-member LLCs without employees can sometimes use the owner's SSN, getting an EIN is fast, free, and protects your personal information. The IRS issues EINs immediately online, making this one of the simplest federal requirements for new business owners.

What it is

An EIN (Employer Identification Number), also called a Federal Tax Identification Number, is assigned by the Internal Revenue Service under Section 6109 of the Internal Revenue Code. The IRS uses your EIN to track business tax obligations including income tax, employment tax, and excise tax filings. The nine-digit number follows the format XX-XXXXXXX and remains with your LLC permanently, even if you change your business name or move to a different state.

You'll need an EIN if your LLC has more than one member (multi-member LLCs are taxed as partnerships by default), has employees, files employment or excise tax returns, or elects to be taxed as a corporation. Single-member LLCs without employees may operate using the owner's Social Security number, but most banks require an EIN to open a business account. Additionally, an EIN shields your SSN from public exposure on tax forms and vendor applications. The IRS Form SS-4 is used to apply, and the process is free whether you apply online, by mail, by fax, or by phone.

Once issued, your EIN cannot be canceled or transferred to another entity. If your LLC undergoes a significant structural change—such as converting from a single-member to multi-member LLC, changing from a partnership to a corporation, or being acquired by new owners—you may need to apply for a new EIN. The IRS provides detailed guidance in Publication 1635 on when a new number is required. Keep your EIN confirmation letter (IRS Notice CP-575) in your permanent records, as you'll reference this number on all federal tax filings, state employer registrations, and business applications.

Where this matters most in practice: Pennsylvania-specific rules. If you want to skip ahead, see compare top providers.

Common mistakes to avoid

Applying before LLC formation is complete. You must have your LLC legally formed and your Articles of Organization filed before applying for an EIN. The IRS requires your official business legal name and formation date, and the application will be rejected if your entity doesn't yet exist in state records.
Listing the wrong responsible party. The responsible party must be an individual with control over the LLC, not the business itself. For single-member LLCs, this is typically the owner; for multi-member LLCs, it's usually the managing member. Using an incorrect SSN or ITIN here can delay processing and complicate future IRS correspondence.
Paying a third party for a free service. The IRS never charges a fee to issue an EIN. Many third-party websites charge $50 to $300 for EIN application services that simply submit the free Form SS-4 on your behalf. Apply directly at irs.gov to avoid unnecessary costs.
Losing the confirmation letter. The IRS issues your EIN immediately but sends the official CP-575 confirmation letter by mail. Many businesses lose this document and later struggle to verify their EIN. Save digital and physical copies, as you'll need it to open bank accounts and apply for licenses.
Not updating the IRS after structural changes. If your LLC adds members, elects S-corp taxation, or merges with another entity, you may need a new EIN. Continuing to use the old EIN after a qualifying change can result in misclassified tax filings and penalties. Consult IRS Publication 1635 or a tax professional before making major structural changes.

Frequently asked questions

Do I need an EIN for a single-member LLC with no employees?

Technically no—the IRS allows single-member LLCs taxed as disregarded entities to use the owner's Social Security number. However, most banks require an EIN to open a business account, and having one protects your SSN from exposure on public forms. Getting an EIN is free and instant, so it's recommended even if not legally required.

How long does it take to get an EIN?

If you apply online at irs.gov, you receive your EIN immediately upon completing the application. The IRS also accepts applications by fax (processed within four business days) and by mail (processed within four weeks). International applicants without a U.S. SSN or ITIN must apply by phone or fax, as the online system requires a U.S. tax identification number.

Can I use my EIN to hire employees in any state?

Yes, your federal EIN is valid nationwide and is required for all federal employment tax filings (Form 941, Form 940, W-2s). However, you must also register separately with your state's labor and revenue departments for state withholding, unemployment insurance, and workers' compensation. Your EIN will be used in those state registrations.

What happens if I need to change my LLC's tax classification?

You can change your LLC's federal tax classification by filing IRS Form 8832 (Entity Classification Election) without getting a new EIN, as long as the LLC's legal identity remains the same. For example, electing S-corp status (Form 2553) or switching from partnership to corporation taxation does not require a new EIN. But if ownership structure changes fundamentally (e.g., a new LLC is formed to acquire the old one), a new EIN is required per IRS Publication 1635.

Is my EIN public information?

Your EIN itself is not confidential like your SSN, and it appears on many public documents including tax filings, business licenses, and invoices. However, the IRS does not publish a searchable database of EINs. Treat your EIN carefully—while not as sensitive as an SSN, it can be used in identity theft or fraudulent filings if someone impersonates your LLC. The IRS recommends safeguarding your CP-575 letter and only sharing your EIN when legally required.

Authoritative sources

Affiliate disclosure: some links on AthenAI earn us a commission at no extra cost to you. We only recommend tools we use ourselves; see our methodology.

Next step

Once you have your EIN, you're ready to open a business bank account and finalize your LLC's operational setup. AthenAI's formation guide walks you through every federal and state requirement in order, ensuring you don't miss critical steps like state tax registrations or BOI reporting. If you need a business banking partner, Mercury Bank offers streamlined account opening for LLCs with no monthly fees and integrated financial tools. Start your formation with AthenAI today to get your EIN and complete your LLC setup with confidence.

Skip the research — let AthenAI handle your LLC paperwork