What Is the Difference Between an EIN and ITIN for Non-Resident Founders?

The EIN and ITIN are two different IRS identification numbers that serve two different purposes. Non-resident founders confuse them constantly — and the confusion creates real filing problems when the wrong number is used on the wrong form, or when a founder applies for one but not the other.

An EIN (Employer Identification Number) identifies a US business entity. It is the entity's tax ID, used to open bank accounts, file tax returns for the LLC, and receive payments. Every US LLC needs one. An ITIN (Individual Taxpayer Identification Number) identifies a foreign individual who has US tax filing obligations but does not qualify for a Social Security Number (SSN). Not every non-resident LLC owner needs an ITIN, but those who have US-source income taxable at the individual level, need to file a personal US tax return, or want to claim treaty benefits on Form W-8BEN do. The EIN is obtained by filing Form SS-4 with the IRS. The ITIN is obtained by filing Form W-7 with a federal tax return. They are applied for separately, processed separately, and used in different contexts.

I have held an EIN for my US entities since 2007 and have worked with non-resident founders who needed ITINs to claim treaty benefits. The overlap between the two numbers is small, but the moments where you need the right one are high-stakes.

EIN: the business identifier

The EIN is a 9-digit number (formatted XX-XXXXXXX) assigned by the IRS to a US business entity. It functions as the entity's Social Security Number — used wherever the entity needs to identify itself for tax, banking, and business purposes.

What an EIN is used for:

Every US LLC needs an EIN. There is no exception. A single-member LLC owned by a foreign person still needs an EIN because the LLC has IRS filing obligations (Form 5472 + pro forma Form 1120) that require the entity to be identified.

How to get an EIN as a non-resident

The online EIN application (IRS EIN Assistant) requires the responsible party to have a Social Security Number (SSN) or ITIN. Non-residents who do not have either cannot use the online application.

For non-residents without an SSN or ITIN, the process is:

Option 1: Fax Form SS-4. Download Form SS-4 from the IRS website, complete it with the foreign responsible party's information (passport number, foreign address), and fax it to the IRS at (855) 641-6935. Processing time is 4-8 weeks. The IRS will fax back a confirmation letter with the EIN.

Option 2: Call the IRS. Non-residents can call the IRS Business & Specialty Tax Line at (267) 941-1099 (not a toll-free number) Monday through Friday, 6:00 AM to 11:00 PM Eastern Time. An EIN can be issued over the phone during the call. This is the fastest method, but wait times vary from 15 minutes to over an hour.

Option 3: Use a formation service. Stripe Atlas, Firstbase, and Doola all include EIN obtainment in their formation packages. They file Form SS-4 on behalf of the founder. Processing time varies from 1-6 weeks depending on IRS backlogs.

Option 4: Mail Form SS-4. Mail the completed form to: Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999. Processing time is 4-6 weeks. This is the slowest method and is used as a fallback when fax and phone are unavailable.

The EIN is free. The IRS does not charge for it. Formation services that charge separately for "EIN obtainment" are charging for the labor of filing the form, not for the number itself.

ITIN: the individual identifier

The ITIN is a 9-digit number (formatted 9XX-XX-XXXX, always starting with 9) assigned by the IRS to foreign individuals who have US tax obligations but do not qualify for a Social Security Number.

What an ITIN is used for:

Not every non-resident LLC owner needs an ITIN. The ITIN is needed when the individual (not the entity) has a US tax filing obligation or needs to claim treaty benefits. A non-resident who owns a single-member LLC, has no US-source income at the individual level, and does not need to claim treaty benefits may not need an ITIN.

When a non-resident LLC owner needs an ITIN

The ITIN becomes necessary in these specific situations:

Situation 1: US-source income at the individual level. If the non-resident earns income from US sources that is not flowing through the LLC — such as rental income from US property, royalties from US publishers, or consulting payments received directly (not through the LLC) — that income is reported on Form 1040-NR, which requires an ITIN.

Situation 2: Tax treaty benefit claims. If the founder wants to claim a reduced withholding rate under a US tax treaty, Form W-8BEN requires a US taxpayer identification number. Without an SSN, the ITIN fills this role. The treaty benefit may reduce the 30% default withholding on certain income types (interest, dividends, royalties) to a lower rate or zero.

Situation 3: Certain state tax filings. Some states require the individual member of an LLC to have a taxpayer identification number for state-level filings, even if the individual has no federal filing obligation at the individual level.

Situation 4: Banking. Some US banks request the individual owner's SSN or ITIN as part of the LLC account opening process, in addition to the LLC's EIN. Mercury and Relay may request the owner's ITIN or passport number during their KYC (Know Your Customer) process.

How to get an ITIN

The ITIN application process is more involved than the EIN process.

Step 1: Complete Form W-7. This is the Application for IRS Individual Taxpayer Identification Number.

Step 2: Attach a federal tax return. The IRS issues ITINs only when the applicant has a US tax filing obligation. Form W-7 is submitted with the tax return that requires the ITIN (usually Form 1040-NR). There are limited exceptions where a tax return is not required (e.g., claiming treaty benefits via Form W-8BEN for third-party withholding).

Step 3: Provide identity documentation. The applicant must submit original documents or certified copies: passport (a passport alone satisfies the identity and foreign status requirement), or a combination of national ID, birth certificate, and foreign status documentation.

Step 4: Submit. Mail the Form W-7 + tax return + documents to: Internal Revenue Service, ITIN Operation, P.O. Box 149342, Austin, TX 78714-9342. Alternatively, apply in person at an IRS Taxpayer Assistance Center or through a Certifying Acceptance Agent (CAA).

Processing time: 7-11 weeks by mail. In-person at a TAC or through a CAA can be faster.

The risk of mailing original identity documents (passport) to the IRS is real. The IRS has historically been slow to return original documents. Using a CAA avoids this risk — the CAA certifies copies of the documents, and the originals stay with the applicant.

EIN vs ITIN: side-by-side

The common confusion: using an ITIN where an EIN is required, or vice versa. Form 5472 and the pro forma Form 1120 use the LLC's EIN. Form 1040-NR and Form W-8BEN use the individual's ITIN. Swapping them causes IRS processing errors and delays.

The sequence for most non-resident LLC owners

Step 1: Form the LLC. File articles of organization with the state.

Step 2: Obtain the EIN. File Form SS-4 by fax, phone, or through a formation service. This is needed immediately — bank accounts and payment processors require it.

Step 3: Determine if you need an ITIN. If you have US-source income at the individual level, need to claim treaty benefits, or a bank requires it for account opening, apply for the ITIN. If your only US connection is the LLC and all income flows through the entity, you may not need one immediately.

Step 4: Apply for the ITIN if needed. File Form W-7 with the relevant tax return. Plan for 7-11 weeks of processing time.

This sequence matters because the EIN is needed within days of formation (to open a bank account), while the ITIN is needed only when individual-level US tax obligations arise. Applying for both simultaneously is possible but unnecessary for most founders. The formation guide walks through this sequence in context.

Common mistakes

Mistake 1: Assuming an EIN replaces an ITIN. The EIN identifies the LLC. If you personally have a US tax filing obligation (Form 1040-NR), you need your own taxpayer identification number. The LLC's EIN does not substitute.

Mistake 2: Waiting for the ITIN to form the LLC. The LLC formation and EIN application do not require an ITIN. Founders who wait for their ITIN before starting the LLC process lose weeks unnecessarily.

Mistake 3: Applying for an ITIN without a tax return. The IRS rejects Form W-7 applications that are not accompanied by a federal tax return (with limited exceptions). Applying "just to have one" without an attached Form 1040-NR will be rejected.

Mistake 4: Mailing a passport to the IRS. Using a Certifying Acceptance Agent avoids sending original identity documents through the mail. The IRS processing center in Austin has a history of slow document returns.

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Frequently Asked Questions

Do I need both an EIN and an ITIN for my US LLC?

You always need an EIN for the LLC. An ITIN is needed only if you have US tax filing obligations at the individual level — such as US-source income reported on Form 1040-NR, or if you want to claim treaty benefits on Form W-8BEN. Many non-resident LLC owners operate with only an EIN for years, adding an ITIN later when individual-level obligations arise.

Can I get an EIN without an ITIN or SSN?

Yes. Non-residents without an SSN or ITIN can obtain an EIN by faxing Form SS-4 to the IRS at (855) 641-6935 or by calling (267) 941-1099. The online EIN application requires an SSN or ITIN, but the fax and phone options accept a foreign passport number. Processing takes 4-8 weeks by fax or same-day by phone. Formation services (Stripe Atlas, Firstbase, Doola) handle this as part of their formation package.

How long does it take to get an EIN and an ITIN?

An EIN can be obtained same-day by calling the IRS, or 4-8 weeks by faxing Form SS-4. Formation services add their own processing time on top of IRS timelines. An ITIN takes 7-11 weeks by mail. Applying in person at an IRS Taxpayer Assistance Center or through a Certifying Acceptance Agent can reduce the ITIN timeline. The EIN process is independent of the ITIN process — they can run in parallel.

Can I use my ITIN to open a US business bank account?

The business bank account is opened in the LLC's name using the LLC's EIN, not the owner's ITIN. However, some banks request the individual owner's SSN or ITIN as part of their KYC verification process when opening the LLC's account. If a bank requests it and you do not yet have an ITIN, provide your passport information instead. Mercury and Wise Business both accept passport information for non-resident LLC owners who do not have an SSN or ITIN.

Related Reading

• How to Form a US LLC as a Non-Resident (2026)
• How Much Does It Cost to Form and Maintain a US LLC?
• What Happens If You Miss Form 5472?
• Stripe Atlas vs Firstbase vs Doola: Pricing Comparison 2026
• Can You Use Wise Business as Your Primary US Bank Account?

References

• IRS: EIN Application — Employer Identification Number
• IRS: Form SS-4 — Application for Employer Identification Number
• IRS: ITIN — Individual Taxpayer Identification Number overview
• IRS: Form W-7 — Application for IRS Individual Taxpayer Identification Number
• IRS: Form W-8BEN — Certificate of Foreign Status of Beneficial Owner
• IRS: Form 1040-NR — US Nonresident Alien Income Tax Return
• IRS: Form 5472 — Information Return of a 25% Foreign-Owned US Corporation
• IRS: Certifying Acceptance Agents — CAA program for ITIN applications
• Mercury — US business banking platform
• Wise Business — Multi-currency business account

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