What Is an EIN and Why Does Your Business Need One?

If you're forming a U.S. LLC, one of the first tasks after your LLC is approved is obtaining an EIN — Employer Identification Number. Think of it as the Social Security Number for your business. It's issued by the IRS and is required for almost everything business-related in the United States.

In this article, we'll explain exactly what an EIN is, who needs one, and how to get yours.

What Is an EIN?

An EIN (Employer Identification Number) is a nine-digit number assigned by the IRS in the format XX-XXXXXXX. It's also called a Federal Employer Identification Number (FEIN) or Federal Tax ID Number.

The IRS uses EINs to identify business entities for tax purposes. Just as individuals use Social Security Numbers to file taxes, businesses use EINs.

Who Needs an EIN?

Your LLC needs an EIN if any of the following apply:

• You want to open a U.S. business bank account
• You have or plan to hire employees
• You file certain business tax returns (excise, employment)
• You want to apply for business credit
• You work with clients or partners who require a tax ID for payments
• You plan to operate a Keogh plan (retirement)

In practice: almost every LLC needs an EIN. Without one, you can't open a business bank account, apply for business credit cards, or properly separate your business and personal finances.

EIN vs. SSN: What's the Difference?

Your Social Security Number (SSN) is your personal tax identifier — tied to you as an individual. An EIN is tied to your business entity (the LLC). Using your business EIN instead of your personal SSN protects your privacy and clearly separates your personal and business finances — which is critical for maintaining your LLC's liability protection.

How to Get an EIN

Option 1: Apply Online (U.S. Residents with SSN/ITIN — Free, Instant)

If you have a Social Security Number or Individual Taxpayer Identification Number (ITIN), you can apply for an EIN directly on the IRS website (irs.gov) using the EIN Online Assistant. The process takes about 15 minutes and your EIN is issued immediately. It's completely free — the IRS does not charge for EINs.

Option 2: Apply by Fax or Mail (Non-Residents Without SSN)

If you're a non-resident without an SSN or ITIN, you cannot use the online EIN application. Instead, you must complete IRS Form SS-4 and submit it by fax or mail to the IRS.

• By fax: The IRS typically responds within 4 business days
• By mail: Can take 4-6 weeks
• Cost: Free (only cost is postal/fax)

Option 3: Use a Third-Party EIN Service

Many formation services offer EIN assistance as part of their LLC formation package. This is useful if you're unfamiliar with the IRS process or want someone else to handle the paperwork. Costs typically range from $50 to $150 as an add-on service.

What Information Do You Need to Apply?

When applying for an EIN (Form SS-4), you'll need:

• Legal name of the LLC
• Trade name (if different)
• Business address (can be international)
• Responsible party's name and SSN/ITIN (for non-residents: name and ITIN or "foreign" status)
• Reason for applying (new business)
• Date the business was started
• Type of entity (LLC)
• Number of employees (usually 0 to start)
• Principal activity/business type

Can Non-Residents Apply Without an ITIN?

Yes. Non-resident LLC owners who are not the "responsible party" for a U.S. business can apply for an EIN on Form SS-4. In line 7b (responsible party's SSN/ITIN), you can write "foreign" or "N/A" — the IRS will still issue the EIN. You must apply by fax or mail, not online.

Note: Some formation services claim you "must" have an SSN to get an EIN — this is false. Non-residents can and do obtain EINs regularly without SSNs.

What to Do After Getting Your EIN

1. Keep it safe: Store your EIN letter (CP-575) in a secure location — you'll need it repeatedly
2. Open a business bank account: Most banks require your EIN and LLC formation documents
3. Set up business credit: Register with Dun & Bradstreet to start building a business credit profile
4. File taxes: Consult a CPA about your U.S. federal tax obligations for the LLC

Common EIN Questions

Can I change my EIN?

Generally no — an EIN is permanent. However, if you change your business structure (e.g., from sole proprietorship to LLC), you'll need a new EIN. Changes within an LLC structure (new members, name change) don't require a new EIN.

Can I use one EIN for multiple businesses?

No. Each legal business entity requires its own EIN. If you own two LLCs, each LLC needs its own separate EIN.

Is an EIN the same as a state tax ID?

No. An EIN is a federal identifier from the IRS. Some states also require a separate state tax ID for sales tax, payroll, or other state-level tax purposes. Requirements vary by state.