Understanding the ITIN and Whether You Need It
Many founders who form a U.S. LLC from abroad hit the same wall a few weeks in: a payment processor, lender, or accountant asks for an "ITIN." If you are a U.S. citizen, this number is rarely on your radar, but for a non-resident owner of a U.S. business, an ITIN can be the difference between filing your taxes properly and watching a refund sit in IRS limbo.
The Individual Taxpayer Identification Number (ITIN) is a nine-digit tax ID issued by the IRS to people who have a U.S. tax filing requirement but cannot get a Social Security Number (SSN). It is purely a tax processing number, not work authorization or an immigration document. For non-resident LLC owners, an ITIN typically becomes relevant once income flows through the LLC to your personal U.S. tax return, once your home country's tax treaty benefits need to be claimed, or once a U.S. payor needs to issue a Form 1099 in your name.
This article walks through when an ITIN is actually required for a non-resident business owner, how it differs from an EIN, the W-7 application process step by step, and the typical timelines you can expect. We also cover how Slash can support your business’s finances after the ITIN arrives. That includes setting up U.S. banking, managing USD balances as a global business, sending SWIFT payments to 180+ countries, and using stablecoins alongside traditional payment rails.¹, ⁴
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ITIN vs EIN for Non-Resident LLC Owners: What's the Difference?
The most common source of confusion for non-resident founders is mixing up the ITIN with the EIN. Both are nine digits, both come from the IRS, and both are used on tax forms, but they identify different things:
ITIN identifies the individual taxpayer
An ITIN is issued to a person. Specifically, it is issued to a person who must file a U.S. tax return or be reported on a U.S. tax document but is not eligible for an SSN. As a non-resident, that often means you, the foreign owner, when your LLC's activity creates a personal U.S. filing obligation.
ITINs always start with the digit 9 and follow the format 9XX-XX-XXXX. They are issued by the IRS Individual Taxpayer Identification Number Operation in Austin, Texas.
EIN identifies the business entity
An EIN, or Employer Identification Number, is issued to the LLC itself. It is the business's federal tax ID and is what U.S. banks, payment processors, and the IRS use to identify the entity. A non-resident-owned single-member LLC typically gets an EIN by submitting Form SS-4 to the IRS by fax or mail, since the online portal is only available to applicants with an SSN or existing ITIN.
EINs follow the format XX-XXXXXXX and are issued through the IRS Business and Specialty Tax Line.
Which one do you need first?
Most non-resident founders will apply for an EIN before an ITIN. The EIN is what opens U.S. business bank accounts, lets you sign up for payment processors, and identifies the LLC on most state filings. You can get an EIN without an ITIN by entering "Foreign" in the SSN field on Form SS-4. The ITIN often becomes necessary only after the LLC generates income that requires personal-level reporting, or when a treaty benefit claim is filed.
When You Need an ITIN as a Non-Resident LLC Owner
Not every non-resident LLC owner needs an ITIN. The IRS issues ITINs based on a documented tax purpose, so applying without one will typically result in rejection. Here are the most common scenarios where an ITIN becomes necessary for a non-resident running a U.S. LLC:
1. Filing a U.S. personal tax return tied to LLC income
If your single-member LLC earns income that is effectively connected with a U.S. trade or business, you may be required to file Form 1040-NR (U.S. Nonresident Alien Income Tax Return). That return requires a taxpayer identification number, and if you don't have an SSN, the IRS expects an ITIN. A common trigger is a U.S.-source service business or U.S.-based inventory operation where income flows through the disregarded entity to you personally.
2. Claiming a tax treaty benefit
The U.S. has tax treaties with roughly 60 countries that may reduce or eliminate withholding on certain payments. Claiming treaty benefits often requires submitting Form W-8BEN to a U.S. payor, and the form asks for a U.S. taxpayer identification number. Without an ITIN, the payor may have to withhold the full statutory rate (often 30%) regardless of treaty entitlement.
3. Being listed on a Form 1099 or partnership K-1
If a U.S. customer pays your LLC and treats you (rather than the LLC) as the recipient of services, they may issue a Form 1099. This is a common relationship between U.S. businesses and overseas contractors. Multi-member LLCs taxed as partnerships also issue Schedule K-1 to each partner. Both forms require a taxpayer identification number for each individual. Foreign partners and recipients typically use an ITIN.
4. Form 5472 filings (in some cases)
Foreign-owned single-member LLCs treated as disregarded entities must file Form 5472 to report transactions between the LLC and its foreign owner. Form 5472 itself does not require an ITIN for the foreign owner (the entity uses its EIN), but related forms or treaty claims tied to the same activity sometimes do.
When you probably do not need an ITIN
If your only activity is holding a U.S. bank account, receiving payments into a disregarded entity, and filing Form 5472 plus a pro forma 1120, you may not need an ITIN at all. Many non-resident founders can operate this way for years. The trigger for needing an ITIN is almost always a personal U.S. filing or a treaty claim, not the existence of the LLC.
How to Apply for an ITIN: The W-7 Process for Non-Resident LLC Owners
The ITIN application uses Form W-7. The form itself is short, but the supporting documents and routing options can complicate the process. Here is how it typically plays out:
Step 1: Confirm a qualifying tax purpose
The IRS will reject a W-7 that is not tied to one of the qualifying tax reasons in the form's checkbox list. The most common reasons used by non-resident LLC owners are:
- Reason (a): Non-resident alien required to obtain an ITIN to claim a tax treaty benefit.
- Reason (b): Non-resident alien filing a U.S. federal tax return.
- Reason (h): Other (followed by an exception or treaty article).
If none of those situations applies yet, you may need to wait until you have a qualifying filing requirement, treaty claim, or other IRS-recognized tax purpose before submitting Form W-7.
Step 2: Fill out Form W-7 line by line
The W-7 asks for your full legal name as it appears on your passport, your foreign address, U.S. mailing address (if applicable), date of birth, country of citizenship, foreign tax ID (if your country issues one), and visa or entry information (if applicable). Non-residents who have never been to the U.S. simply leave the entry-information section blank.
Two common mistakes worth avoiding: writing your name in a different order than your passport and using a current address that differs from the one on your passport without supporting documentation. The IRS matches W-7 entries against the identity documents you submit, and mismatches are a frequent rejection cause.
Step 3: Attach a U.S. tax return or treaty document
Most W-7 applications must be physically attached to the tax return that creates the filing requirement. For example, if you are filing a Form 1040-NR for the first time, you mail the W-7, the 1040-NR, and the supporting identity documents together in one envelope. If your tax purpose is a treaty claim under Reason (h), you may attach Form W-8BEN or a similar treaty-claim document instead, depending on the situation.
Step 4: Provide identity and foreign status documents
The IRS requires documentary evidence of both identity and foreign status, and a passport is the only single document that satisfies both. If you cannot submit a passport, you must submit at least two other approved documents, such as a national ID card plus a birth certificate.
You have three options for handling the documents:
- Mail the original passport or certified copies issued by the issuing agency to the IRS in Austin, Texas. The IRS returns originals within roughly 60 days, meaning you will be without your passport during that window.
- Use a Certifying Acceptance Agent (CAA) authorized by the IRS to verify your documents in person so you keep your passport. The CAA submits the W-7 on your behalf along with a certificate of accuracy.
- Visit an IRS Taxpayer Assistance Center in person if you can travel to the U.S. for the appointment.
For most non-resident founders located outside the U.S., a Certifying Acceptance Agent is the most practical route. CAAs operate in many countries, often charge a fee in the $100–$400 range, and remove the need to mail your passport overseas.
Step 5: Submit and wait
After submission, processing typically takes 7–11 weeks during normal IRS operations. Submissions during peak filing season (February through April) and submissions from outside the U.S. can extend toward the upper end of that range. Once processed, the IRS mails the ITIN assignment notice (CP565) to the address listed on the W-7.
Keep a copy of every page submitted. If the IRS sends a rejection notice (CP566 or similar), the most common fixes are correcting an address mismatch, attaching a missing tax return, or upgrading from photocopies to certified copies of the identity document. Fixing issues becomes much easier when you don’t need to recreate your filing from scratch.
Certifying Acceptance Agents vs IRS Mail-In: Choosing the Right ITIN Path
For non-resident LLC owners, the choice between a Certifying Acceptance Agent and direct IRS submission usually comes down to three factors: passport access, cost, and turnaround.
If you cannot be without your passport for two months, a CAA is typically the right choice. CAAs are individuals or firms (often CPAs, EAs, or tax attorneys) authorized by the IRS to verify the identity of ITIN applicants. They review your passport in person or via secure video, prepare the W-7 with a certificate of accuracy, and submit it directly. You keep your original passport.
CAAs can also assist by catching any errors before submission. Many also handle related work such as preparing the underlying 1040-NR or filing the EIN application alongside the ITIN.
If you already need to send your passport to a consulate for an unrelated purpose, or if you have a certified copy issued by your passport-issuing agency, mailing directly to the IRS can save the CAA fee. The trade-off is the lack of pre-submission review and the longer round-trip time if anything is missing.
Once your ITIN arrives, you will want to keep it organized alongside your EIN, articles of organization, operating agreement, and any treaty documents. Slash gives businesses a centralized place to keep those entity records connected to their banking and payment operations, which makes it easier to access the right documents when a customer, lender, accountant, or compliance team asks for them.
ITIN Processing Timelines and What Comes After Approval
Knowing what to expect after submission helps you plan the rest of your U.S. tax and banking setup. Here is a realistic timeline and a list of common next steps:
Typical timeline from application to approval
Processing times shift with IRS workload, but the following ranges are common in normal years:
- Application prepared and submitted by a Certifying Acceptance Agent: 1–2 weeks before submission, then 7–11 weeks IRS processing.
- Application mailed directly to the IRS from outside the U.S.: 9–14 weeks total, including international mail time.
- Submission during peak season (February through April): add 2–3 weeks.
If you have not received a response after 14 weeks, the IRS recommends calling the toll-free number listed on the W-7 instructions to check status. Have your full name and the application reference details ready.
After approval: what to do with your ITIN
The CP565 assignment notice is the only confirmation the IRS sends, so store the original. Then use the ITIN for:
- Filing the 1040-NR or other personal return that triggered the application.
- Submitting Form W-8BEN to U.S. payors to claim treaty benefits and reduce withholding.
- Updating your records with any U.S. payors who issued Forms 1099 to you personally.
- Providing the number to your accountant for future filings.
Renewal and expiration
ITINs expire if they are not used on a federal tax return for three consecutive years. Some older ITINs (those issued before 2013) followed an expiration schedule by middle-digit groups. If your ITIN expires, you can renew it by submitting a new W-7 marked as a renewal, with identity documents but without a new tax return attached.
ITIN, EIN, and Banking: Where Slash Fits In for Non-Resident LLC Owners
Getting an ITIN can sometimes be the slowest step in setting up a non-resident-owned U.S. business. The rest of the stack — business banking, corporate cards, and integrated financial tools — does not need to wait. Modern financial platforms have made the surrounding pieces easier to assemble than ever.
For non-resident founders, the practical pain points are usually: opening a U.S. business bank account without flying to the U.S., accepting U.S. dollar payments efficiently, keeping entity paperwork in one place, and managing FX exposure if revenue and expenses sit in different currencies. Slash addresses these pieces through a unified platform built around the realities of cross-border business, including a Global USD Account that lets you hold and move U.S. dollars without forming a U.S. LLC at all if that turns out to be the simpler path for your situation.³
On the LLC side, once you have your EIN you can apply for the full Slash business platform: FDIC-insured business checking, charge cards with category controls, an integrated treasury account for idle cash, and accounting integrations so your transactions sync into QuickBooks, Xero, or Sage Intacct without manual reentry.² When the ITIN arrives, you can store it inside Entity Documents alongside the rest of your formation paperwork.
Besides global support, here’s what else you
- Slash corporate cards: Earn up to 2% cash back (U.S. only) on your business spending and utilize granular card controls for your team.
- Built-in financial tools: Slash helps you manage invoicing, cash flow tracking, and automate expense management.
- High-yield treasury: Accounts earning up to 3.80% yield from Morgan Stanley and BlackRock with next-day liquidity.⁶
- Flexible payment methods: Same-day ACH, SWIFT wires to 180+ countries, and real-time rails like RTP and FedNow (with no additional per-transaction fees for domestic transfers on Slash Pro).
- Native cryptocurrency support: Send and receive stablecoins like USDC and USDT, with built-in on/off ramps for seamless conversion between fiat and crypto.
- AI financial assistant: Use Twin to analyze spend, set controls, and execute payments directly from your dashboard.
- Accounting integrations: Sync Slash with QuickBooks, Xero, and Sage Intacct, with automatic transaction categorization to simplify reconciliation.
This guide is informational and does not constitute legal or tax advice. Consult a qualified U.S. tax professional for guidance specific to your situation.
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Frequently asked questions
Can I get an ITIN before I form my U.S. LLC?
In most cases, no. The IRS issues ITINs based on a documented tax purpose such as a U.S. tax return filing requirement or a treaty claim. Forming the LLC and generating activity that triggers a personal U.S. filing is what creates the tax purpose for many non-resident founders. If you have an independent reason (for example, you receive U.S.-source royalty income personally) you may apply earlier.
Choosing an LLC Type: Complete Guide for Businesses
Do I need an ITIN to open a U.S. business bank account for my LLC?
Usually not. U.S. business bank accounts are opened in the LLC's name using the EIN, plus your passport for the owner's identity verification. With Slash, non-resident owners can apply online for FDIC-insured business banking using the LLC's EIN and a passport. The ITIN typically becomes relevant later, at tax filing time.
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