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

What exactly is an Employer Identification Number?

An Employer Identification Number (EIN) is a unique 9-digit number the IRS assigns to business entities operating in the United States. The EIN format is XX-XXXXXXX (two digits, a hyphen, and seven digits). The IRS uses the EIN to identify the business entity for tax purposes, similar to how a Social Security Number identifies an individual.

The IRS introduced the EIN system in 1974 as part of the Tax Reform Act. Every type of US business entity can receive an EIN: LLCs, corporations, partnerships, sole proprietorships, trusts, estates, and non-profit organizations. The name "Employer Identification Number" is somewhat misleading because you need an EIN whether or not you have employees. A more accurate name would be "Business Tax Identification Number," which is how most entrepreneurs and accountants refer to it informally.

For Wyoming LLC owners, the EIN is the single most important number you receive after formation. It unlocks US business banking, payment processing, and tax compliance. Without an EIN, your LLC cannot open a bank account, cannot register for Stripe or PayPal, and cannot file required tax returns. The EIN is free to obtain from the IRS and never expires once assigned to your LLC.

The EIN is assigned to the LLC entity itself, not to any individual owner. If the LLC changes ownership, the EIN stays with the LLC. If you own multiple LLCs, each one gets its own separate EIN. The EIN is permanently tied to the entity and cannot be transferred, reused, or reassigned.

Who needs an EIN for their LLC?

Every multi-member LLC is required by the IRS to have an EIN. Single-member LLCs with employees must have an EIN. Single-member LLCs without employees are not strictly required to have one, but an EIN is essential in practice because banks, Stripe, and other financial services require it.

Multi-Member LLCs (Required)

The IRS classifies multi-member LLCs as partnerships for federal tax purposes. Partnerships must have an EIN to file Form 1065 (US Return of Partnership Income) and issue Schedule K-1s to each member. A multi-member Wyoming LLC cannot operate without an EIN. Learn more about EIN for multi-member LLCs.

Single-Member LLCs With Employees (Required)

If your single-member LLC hires employees, the IRS requires an EIN for payroll tax reporting. The EIN appears on Form 941 (quarterly payroll tax return), W-2 forms issued to employees, and 1099 forms issued to contractors. Without an EIN, you cannot process payroll or report employment taxes.

Single-Member LLCs Without Employees (Strongly Recommended)

A single-member LLC owned by a US citizen with an SSN is technically allowed to use the owner's SSN instead of a separate EIN. However, this is impractical because every US bank requires an EIN to open a business account. Stripe, PayPal, and other payment processors require an EIN. Using your SSN on business documents exposes your personal tax ID to vendors, clients, and public records. The EIN is free, so there is no reason to avoid getting one.

Foreign-Owned Single-Member LLCs (Required in Practice)

Non-resident LLC owners must file Form 5472 with a pro-forma Form 1120 annually. This form requires the LLC's EIN. Without an EIN, you cannot comply with this filing requirement, which carries a $25,000 penalty for non-filing. Additionally, no US bank will open a business account without an EIN. For non-residents, the EIN is not optional. Read more at EIN for non-residents without SSN.

Why do banks require an EIN for business accounts?

US banks require an EIN for business account opening because federal regulations (Bank Secrecy Act and USA PATRIOT Act) mandate that banks verify the identity and tax status of business entities. The EIN proves the business is registered with the IRS and enables the bank to report account activity for tax compliance.

When you apply for a business bank account, the bank verifies your EIN against IRS records. This verification confirms the LLC exists, is active, and has a valid federal tax identification number. Banks also use the EIN to file Form 1099-INT (interest income) and comply with IRS information reporting requirements.

Mercury Bank, Relay Bank, and Wise Business all require an EIN during the application process. Mercury asks for the EIN confirmation letter (CP 575) or the IRS determination letter as proof. Relay similarly requires the CP 575 letter. Without this document, the bank cannot verify your EIN and will not open the account. Read the complete banking guide at Mercury Bank for Wyoming LLC.

Traditional banks like Chase, Bank of America, and Wells Fargo also require an EIN. These banks additionally require the business owner's SSN or ITIN for personal identity verification under Customer Identification Program (CIP) requirements. Fintech banks like Mercury and Relay accept foreign passports instead of SSN/ITIN, making them the primary option for non-resident LLC owners. Learn more about US bank account for Wyoming LLC non-residents.

Why does Stripe require an EIN?

Stripe requires an EIN because US financial regulations mandate that payment processors verify the tax identification of businesses they serve. Stripe uses the EIN to file Form 1099-K with the IRS reporting your gross payment volume when thresholds are met.

During Stripe account setup, you enter your Wyoming LLC name and EIN. Stripe verifies the EIN against IRS records in real time. If the LLC name and EIN do not match IRS records, Stripe rejects the application. Ensure the LLC name you enter matches exactly what appears on your Articles of Organization and EIN confirmation letter, including the "LLC" designator.

Stripe also uses the EIN for compliance with Know Your Business (KYB) requirements under the Bank Secrecy Act. The EIN confirms the business is a legitimate US entity registered with the IRS. This is separate from the personal identity verification (passport upload) that Stripe requires for the individual account representative.

Non-resident Wyoming LLC owners set up US Stripe accounts using their EIN and a US bank account (Mercury or Relay). Stripe processes USD transactions at 2.9% + $0.30 per charge and deposits payouts into the linked US bank account every 2 business days. The EIN is essential for this setup because Stripe cannot onboard a business without a verified US tax ID.

Other Payment Processors Requiring EIN

Beyond Stripe, the following payment processors require an EIN for business accounts: PayPal Business, Square, Braintree, Authorize.net, and Amazon Pay. Marketplace platforms like Amazon Seller Central, Shopify Payments, and Walmart Marketplace also require EINs for US business accounts. The EIN is the universal key to US payment processing.

How is the EIN used for tax filing?

The EIN appears on every federal tax return and information form filed by your LLC. The specific forms depend on your LLC structure, ownership, and whether you have employees.

Single-Member LLC (Disregarded Entity)

A single-member LLC owned by a US person is a "disregarded entity" for federal tax purposes. Business income flows through to the owner's personal return (Schedule C of Form 1040). The EIN still appears on bank-related forms (1099-INT), information returns, and any employment tax forms if the LLC has employees.

Foreign-Owned Single-Member LLC

A foreign-owned single-member LLC files Form 5472 (Information Return of a 25% Foreign-Owned US Corporation) with a pro-forma Form 1120 annually. The LLC's EIN appears on both forms. The deadline is April 15, with a 6-month extension available via Form 7004. The penalty for non-filing is $25,000 per form. Learn more at Form 5472 for Wyoming LLC non-residents.

Multi-Member LLC (Partnership)

Multi-member LLCs file Form 1065 (US Return of Partnership Income) using the LLC's EIN. The form reports total income, deductions, and credits. Each member receives a Schedule K-1 showing their individual share. The EIN ties all partnership reporting to the LLC entity. Learn more at EIN for multi-member LLCs.

LLC Electing Corporate Taxation

LLCs that elect S-Corp taxation file Form 1120-S. LLCs that elect C-Corp taxation file Form 1120. Both forms require the LLC's EIN. The election is made on Form 8832 (Entity Classification Election) or Form 2553 (S-Corp election), which also require the EIN.

Employment Taxes

If your LLC has employees, the EIN appears on Form 941 (quarterly payroll tax return), Form 940 (annual federal unemployment tax return), W-2 forms (employee wage statements), and 1099-NEC forms (non-employee compensation for contractors). Payroll processing systems require the EIN to file these forms electronically.

Why do you need an EIN to hire employees?

Federal law requires employers to have an EIN to report and remit payroll taxes. The EIN identifies the employer on all employment tax forms, W-2 wage statements, and 1099 contractor forms. Without an EIN, you cannot legally hire employees or file employment tax returns.

When you hire an employee, you withhold federal income tax, Social Security tax (6.2%), and Medicare tax (1.45%) from their wages. You also pay the employer portion of Social Security (6.2%) and Medicare (1.45%), plus federal unemployment tax (FUTA) of 6% on the first $7,000 of wages. All of these taxes are reported under your LLC's EIN on Form 941 (quarterly) and Form 940 (annual).

At year-end, you issue Form W-2 to each employee showing total wages and taxes withheld. The W-2 includes your LLC's name and EIN. You submit copies of all W-2s to the Social Security Administration. If you pay independent contractors $600 or more in a year, you issue Form 1099-NEC, which also includes your LLC's EIN.

Payroll services like Gusto, ADP, Paychex, and QuickBooks Payroll require your EIN during setup. These services use the EIN to file payroll tax forms electronically with the IRS, Social Security Administration, and state tax agencies on your behalf.

How do you apply for an EIN?

The IRS provides four methods to apply for an EIN: online, fax, mail, and phone. The best method depends on whether you have an SSN or ITIN and how quickly you need the EIN.

Method 1: Online Application (Instant, requires SSN/ITIN)

Visit the IRS EIN Assistant at irs.gov. Answer questions about your LLC structure, select "Limited Liability Company," enter the number of members, and provide the responsible party's SSN or ITIN. The system issues an EIN immediately upon completion. This method is available Monday through Friday, 7:00 AM to 10:00 PM Eastern Time. If you have an ITIN, this is the fastest method.

Method 2: Fax (4-8 weeks, no SSN/ITIN needed)

Complete IRS Form SS-4 and fax to (855) 641-6935. Write "Foreign" in the SSN/ITIN field (Line 7b) if you do not have one. Include a cover sheet with your name, phone number with country code, and email address. The IRS processes faxed applications in 4-8 weeks and mails the EIN confirmation letter (CP 575). This is the primary method for non-residents. Full walkthrough at how to get EIN as a foreign national.

Method 3: Mail (8-12 weeks, no SSN/ITIN needed)

Mail the completed Form SS-4 to: Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999. Processing takes 8-12 weeks. The IRS mails the EIN confirmation letter to the address on the form. This method is the slowest and is not recommended when fax is available.

Method 4: Phone (follow-up only, no SSN/ITIN needed)

Call the IRS at (267) 941-1099 (international, not toll-free) Monday through Friday, 6:00 AM to 11:00 PM Eastern Time. This line is intended for follow-up after fax or mail submission. If the IRS has received and processed your faxed Form SS-4, the agent can provide your EIN over the phone. This method works best 4 weeks after faxing. Read the full application guide at applying for EIN online as a non-resident.

How do you complete IRS Form SS-4?

Form SS-4 (Application for Employer Identification Number) is a one-page IRS form that collects basic information about your LLC. Non-residents complete the same form as US citizens, with "Foreign" entered in the SSN/ITIN field. Download Form SS-4 from irs.gov.

Line-by-Line Instructions

1. Line 1 (Legal name): Enter the exact LLC name as filed with Wyoming Secretary of State, including "LLC" designator. Example: "Global Ventures LLC."
2. Line 2 (Trade name): Enter your DBA (doing business as) name if different from the legal name. Leave blank if you operate under the LLC name.
3. Lines 4a-4b (Mailing address): Enter the registered agent's Wyoming address. This is where the IRS mails the EIN confirmation letter.
4. Lines 5a-5b (Street address): Enter the same address as Lines 4a-4b unless different.
5. Line 6 (County and state): Enter the county of the registered agent's address and "WY" for Wyoming.
6. Line 7a (Responsible party name): Enter your full legal name as it appears on your passport.
7. Line 7b (SSN/ITIN): Enter your SSN or ITIN. If you have neither, write "Foreign" in this field.
8. Line 8a (LLC type): Check "Limited Liability Company (LLC)" and enter the state: "Wyoming."
9. Line 8b (Number of members): Enter the number of LLC members (1 for single-member, 2+ for multi-member).
10. Line 9a (Type of entity): Check "Started new business" and describe your primary business activity.
11. Line 10 (Date business started): Enter the date Wyoming approved your Articles of Organization.
12. Lines 12-16: Enter expected employees (if any), principal activity, and NAICS code describing your industry.
13. Line 18 (Signature): Sign and date the form.

For the complete list of documents to gather before completing Form SS-4, see documents needed for EIN application.

What should you do after receiving your EIN?

After receiving your EIN confirmation letter (CP 575), complete four immediate steps: secure the letter, open a bank account, register for payment processing, and set up your accounting system.

Step 1: Secure the EIN Confirmation Letter

The CP 575 letter is the official document proving your EIN. Make digital copies (scan or photograph) and store them in at least two secure locations (cloud storage and local backup). Banks, Stripe, and tax preparers will request this letter. Obtaining a replacement from the IRS takes weeks and requires a phone call to (267) 941-1099 for international filers.

Step 2: Open a US Business Bank Account

Apply to Mercury Bank for Wyoming LLC or Relay Bank with your Articles of Organization, CP 575 letter, operating agreement, and passport. Mercury and Relay approve most applications within 1-5 business days. The EIN is the primary identifier the bank uses for your business account.

Step 3: Register for Stripe

Create a Stripe account at stripe.com, select "United States" as the business country, enter your LLC name and EIN, and connect your Mercury or Relay bank account for payouts. Stripe verifies the EIN against IRS records during the application. Approval takes 1-3 business days.

Step 4: Set Up Accounting

Connect your bank account to accounting software (QuickBooks, Xero, or Wave). The EIN appears on your tax profile in these systems. Proper accounting from day one simplifies Form 5472 filing (for foreign-owned LLCs) and Form 1065 filing (for multi-member LLCs). Categorize all transactions and keep records of distributions between the LLC and its owners.

Step 5: File Required Annual Forms

Mark your calendar for annual filing deadlines. Foreign-owned single-member LLCs file Form 5472 + pro-forma 1120 by April 15. Multi-member LLCs file Form 1065 by March 15. Wyoming annual reports are due on the first day of the LLC's anniversary month. All forms reference the LLC's EIN.

What are common EIN mistakes to avoid?

The most common EIN mistakes are applying online without an SSN/ITIN, mismatching the LLC name, losing the CP 575 letter, and applying before LLC formation is complete. Avoiding these mistakes saves weeks of delays and potential compliance issues.

Mistake 1: Using the Online Application Without SSN/ITIN

The IRS online EIN application requires a valid SSN or ITIN. Non-residents without either who attempt the online application waste time and receive a rejection after completing all fields. Always use fax submission (Form SS-4) if you do not have an SSN or ITIN.

Mistake 2: LLC Name Mismatch

The LLC name on Form SS-4 must match the name on your Articles of Organization exactly. Common errors include omitting "LLC" from the name, using a trade name instead of the legal name, or misspelling the name. A mismatch creates problems when banks try to verify the EIN against IRS records.

Mistake 3: Applying Before LLC Formation

You must form the LLC before applying for an EIN. The IRS requires an active business entity. If you fax Form SS-4 before Wyoming approves your Articles of Organization, the IRS may reject the application. Always wait for confirmation that your LLC is officially formed.

Mistake 4: Losing the CP 575 Letter

The CP 575 letter is issued once and is not automatically replaced. Banks require this letter for account opening. If lost, you must call the IRS at (267) 941-1099 to request verification. The process is slow and unreliable for international callers. Scan and back up the letter immediately upon receipt.

Mistake 5: Paying Third-Party Fees

The IRS does not charge for EIN applications. Third-party websites that charge $50-$300 for "EIN filing services" are submitting the same free Form SS-4 on your behalf. While formation services that include EIN as part of a comprehensive package provide genuine value, standalone EIN-only services are overpriced for what amounts to filling out a one-page form.

Frequently Asked Questions

Does an EIN expire?

No. Once assigned, an EIN permanently belongs to the LLC. It never expires and requires no renewal. If the LLC dissolves, the EIN is retired and never reissued to another entity. An inactive LLC retains its EIN indefinitely.

Can I have multiple EINs for one LLC?

No. Each LLC receives one EIN. If you need a new EIN for the same entity (for example, after a structural change from single-member to multi-member), you must apply for a new one. The old EIN becomes inactive. Contact the IRS if you are unsure whether your structural change requires a new EIN.

Is an EIN the same as a tax ID number?

Yes. EIN, Federal Tax ID Number (FTIN), Federal Employer Identification Number (FEIN), and Tax ID Number (TIN) all refer to the same 9-digit number assigned by the IRS. Different banks, forms, and services may use different names, but they all mean the EIN.

What if I entered the wrong information on Form SS-4?

If the IRS has already assigned an EIN with incorrect information, call (267) 941-1099 (international) to correct the records. Common corrections include name changes, address changes, and responsible party updates. For a responsible party change, file Form 8822-B within 60 days of the change.