EIN vs ITIN: What Non-Resident Founders Need

Non-resident founders confuse the EIN and ITIN constantly. I get it. Both are 9-digit IRS numbers, both relate to taxes, and the acronyms blur together after the third form you download. But they identify completely different things, and putting the wrong one on the wrong form will stall your filings.

I have held an EIN for my US entities since 2007. Over the years I have worked with non-resident founders who needed ITINs to claim treaty benefits, and the pattern is always the same: they assume one number covers everything. It does not.

EIN: the business identifier

Think of the EIN (XX-XXXXXXX format) as your LLC's Social Security Number. The IRS assigns it to the entity, and it shows up everywhere the LLC needs to prove who it is.

What an EIN is used for:

Every US LLC needs an EIN, no exception. Even a single-member LLC owned by a foreign person has IRS filing obligations (Form 5472 + pro forma Form 1120), and those forms require the entity's EIN.

How to get an EIN as a non-resident

Here is the annoying part. The online IRS EIN Assistant requires an SSN or ITIN. If you have neither, you are locked out of the web form and stuck with slower options:

Option 1: Fax Form SS-4. Download Form SS-4, fill in your passport number and foreign address, and fax it to (855) 641-6935. Expect 4-8 weeks. The IRS faxes back a confirmation letter with the EIN.

Option 2: Call the IRS. Dial (267) 941-1099 (not toll-free), Monday-Friday, 6 AM-11 PM Eastern. You can get the EIN issued on the spot. Wait times range from 15 minutes to over an hour, but this is the fastest path.

Option 3: Use a formation service. Stripe Atlas, Firstbase, and Doola all file Form SS-4 as part of their formation packages. Processing varies from 1-6 weeks depending on IRS backlogs.

Option 4: Mail Form SS-4. Mail to: Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999. Takes 4-6 weeks. Last resort.

The EIN itself is free. If a formation service charges separately for "EIN obtainment," they are charging for the labor of filing the form, not the number.

ITIN: the individual identifier

The ITIN (9XX-XX-XXXX, always starting with 9) identifies you, the foreign individual, not your LLC. The IRS assigns it to people who have US tax obligations but do not qualify for a Social Security Number. Full eligibility details are on the IRS ITIN page.

What an ITIN is used for:

Here is the part most founders get wrong: not every non-resident LLC owner needs an ITIN. You need one when you personally have a US tax filing obligation or want to claim treaty benefits. If your only US connection is the LLC and all income flows through the entity, you may not need an ITIN at all.

When a non-resident LLC owner needs an ITIN

US-source income at the individual level. Rental income from US property, royalties from US publishers, consulting payments you received directly (not through the LLC). All of that goes on Form 1040-NR, which requires an ITIN. The digital nomad tax residency guide covers how these individual obligations interact with residency across jurisdictions.

Tax treaty benefit claims. To claim a reduced withholding rate under a US tax treaty, Form W-8BEN requires a US taxpayer identification number. Without an SSN, that means an ITIN. Treaty benefits can reduce the default 30% withholding on interest, dividends, and royalties to a lower rate or zero.

Certain state tax filings. Some states require the individual LLC member to have a taxpayer identification number for state filings, even without a federal obligation at the personal level.

Banking. Some US banks ask for the owner's SSN or ITIN during the LLC account opening process, on top of the LLC's EIN. Mercury and Relay may request your ITIN or passport number as part of KYC.

How to get an ITIN

This process is more painful than the EIN.

Step 1: Complete Form W-7.

Step 2: Attach a federal tax return. The IRS only issues ITINs when you have a US tax filing obligation. You submit Form W-7 with the return that requires the ITIN (usually Form 1040-NR). Limited exceptions exist, like claiming treaty benefits via Form W-8BEN for third-party withholding.

Step 3: Provide identity documentation. Original documents or certified copies. A passport alone satisfies both the identity and foreign status requirement. Otherwise you need a combination of national ID, birth certificate, and foreign status docs.

Step 4: Submit. Mail everything to: Internal Revenue Service, ITIN Operation, P.O. Box 149342, Austin, TX 78714-9342. Or apply in person at an IRS Taxpayer Assistance Center or through a Certifying Acceptance Agent (CAA).

Processing time: 7-11 weeks by mail. A TAC or CAA can be faster.

I strongly prefer the CAA route. Mailing your original passport to the IRS is a real risk. They have been slow to return documents historically, and you do not want to be without a passport for three months. A CAA certifies copies so your originals stay with you.

EIN vs ITIN: side-by-side

The mistake I see most often: swapping these two on forms. Form 5472 and pro forma Form 1120 take the LLC's EIN. Form 1040-NR and Form W-8BEN take the individual's ITIN. Mix them up and your filing stalls at IRS processing. The cross-border compliance checklist shows where each number appears across your full filing obligations.

The sequence for most non-resident LLC owners

Step 1: Form the LLC. File articles of organization with the state. The best state for LLC analysis covers cost, privacy, and compliance for non-residents.

Step 2: Get the EIN. File Form SS-4 by fax, phone, or through a formation service. You need this immediately. No EIN means no bank account and no payment processing.

Step 3: Figure out if you need an ITIN. Do you have US-source income at the individual level? Need treaty benefits? Did a bank ask for it during account opening? If yes to any of those, apply. If your only US connection is the LLC and everything flows through the entity, you probably do not need one yet.

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

The order matters. Your EIN is needed within days of formation to open a bank account. The ITIN can wait until individual-level tax obligations actually arise. I have seen founders delay LLC formation for weeks because they thought they needed an ITIN first. They did not. The formation guide walks through the full sequence.

Common mistakes

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 number. The LLC's EIN does not count.

Waiting for the ITIN to form the LLC. You do not need an ITIN to form an LLC or get an EIN. Founders who wait lose weeks for no reason. Get a registered agent, file, and move forward.

Applying for an ITIN without a tax return. The IRS rejects Form W-7 applications that are not attached to a federal tax return (with limited exceptions). You cannot apply "just to have one."

Mailing a passport to the IRS. As I mentioned above, use a Certifying Acceptance Agent. The Austin processing center has a history of slow document returns, and being without your passport for months is a bad position to be in as a cross-border founder.

Key Takeaways

• EIN = your LLC's tax ID (XX-XXXXXXX). ITIN = your personal tax ID as a foreign individual (9XX-XX-XXXX). Every LLC needs an EIN. Not every owner needs an ITIN.
• No SSN? Get your EIN by faxing Form SS-4 (4-8 weeks) or calling (267) 941-1099 (same-day). Free either way. The online form is locked without an SSN or ITIN.
• You need an ITIN when you personally have US-source income (Form 1040-NR), want treaty benefits (Form W-8BEN), or a bank requires it for KYC. Processing: 7-11 weeks by mail.
• Get the EIN first. You need it within days of formation to open a bank account. The ITIN can wait. Do not hold up your LLC for it.

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Frequently Asked Questions

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

You always need the EIN. The ITIN depends on your personal situation. If you have US-source income reported on Form 1040-NR, or you want to claim treaty benefits on Form W-8BEN, yes. Otherwise, many non-resident LLC owners operate with only an EIN for years and add an ITIN later when personal obligations come up.

Can I get an EIN without an ITIN or SSN?

Yes. Fax Form SS-4 to (855) 641-6935 or call (267) 941-1099. The online application is blocked without an SSN or ITIN, but fax and phone accept a foreign passport number. Processing: 4-8 weeks by fax, same-day by phone. Formation services like Stripe Atlas, Firstbase, and Doola handle this as part of their package.

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

EIN: same-day by phone, 4-8 weeks by fax. Formation services add their own processing time on top. ITIN: 7-11 weeks by mail. In-person at a Taxpayer Assistance Center or through a CAA can cut that down. The two processes are independent and can run in parallel.

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

The LLC bank account uses the LLC's EIN, not your ITIN. But some banks ask for the owner's SSN or ITIN as part of KYC when opening the LLC's account. If you do not have an ITIN yet, provide your passport instead. Mercury and Wise Business both accept passport information for non-resident LLC owners.

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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