If you’re running a US business and you don’t have a Social Security Number, sooner or later you may need to think about an ITIN — but not always as soon as you’d expect. It’s the nine-digit number that lets you file a personal US tax return and claim treaty benefits, without ever needing SSN eligibility. This guide covers what an ITIN actually is, who actually needs one (and who doesn’t), how the Form W-7 application works, and what to expect once you have it.
An ITIN is a federal tax ID for people who need to file US taxes but don’t qualify for a Social Security Number. It doesn’t grant work authorization or immigration status — it’s strictly a tax processing number. You don’t need one to form a US LLC or to get an EIN — it only comes into play once you have a personal US tax filing to make.
What is an ITIN?
An Individual Taxpayer Identification Number (ITIN) is a nine-digit number the IRS issues to people who have a US tax obligation but aren’t eligible for a Social Security Number. It’s always formatted like an SSN and always starts with a 9: 9XX-XX-XXXX. The IRS created the ITIN in 1996 for exactly this reason — a US tax filing shouldn’t depend on immigration status.
The most recently published IRS figures, from 2022, show roughly 3.8 million ITIN returns filed, reporting $14.4 billion in taxable income and contributing about $6.5 billion toward Social Security and Medicare — programs ITIN holders fund but can’t draw benefits from. Processing a new application typically takes 7–11 weeks. Source: IRS, Individual Taxpayer Identification Number — checked September 2026.
An ITIN is for federal tax purposes only. It doesn’t provide work authorization, immigration status, or eligibility for Social Security benefits or the Earned Income Tax Credit.
ITIN vs. SSN vs. EIN
These three numbers get mixed up constantly. Here’s the distinction that matters:
| Feature | ITIN | SSN | EIN |
|---|---|---|---|
| Issued to | Individuals without SSN eligibility | Citizens, residents, eligible visa holders | Business entities |
| Purpose | File federal taxes | Employment & benefits | Business identification |
| Starts with | 9 | Any digit | Varies |
| Work authorization | No | Yes, if eligible | N/A |
| Application | Form W-7 | Social Security Administration | Form SS-4 |
Every US business needs an EIN, regardless of whether its owner has an ITIN, an SSN, or neither — see how to get an EIN without an SSN or ITIN. Forming an LLC and getting its EIN never requires an ITIN. The two numbers serve different purposes: the EIN identifies your business, while an ITIN (if you ever need one) lets you personally file a US tax return.
Who actually needs an ITIN
You need one if you have a US federal tax purpose and don’t qualify for an SSN. That covers a few common cases:
- You’re a nonresident alien filing a US personal tax return.
- You’re claiming a tax treaty benefit.
- You’re a dependent or spouse of a US citizen or resident who needs to be listed on a return.
- You’re a foreign business owner with US-source income that requires you to file personally (see our small business tax guide for when that applies to a foreign-owned LLC).
You don’t need one if you’re a US citizen, hold a green card, have a work visa that makes you SSN-eligible, already have an SSN, or you’re not required to file a US personal return at all. That last case is common: owning a foreign-owned single-member LLC only creates an entity-level Form 5472 filing, which doesn’t require an ITIN — you’d only need one if your LLC’s income is effectively connected with a US trade or business and you have to file Form 1040-NR.
What counts as a “federal tax purpose”
In practice, this means one of a few things applies to you: you’re legally required to file a federal return, you want to claim a refund or treaty benefit, or a federal filing you’re making requires a tax ID from you personally. If none of those apply yet, you don’t need to apply yet.
How to apply for an ITIN: step by step
The standard application combines Form W-7, proof of identity and foreign status, and the federal return that creates the need for the number. Here’s how to put it together.
- Confirm eligibility and a federal tax purpose. You must be ineligible for an SSN and need a US taxpayer identification number for a return, treaty claim, or another documented tax purpose allowed by the Form W-7 instructions. Owning an LLC by itself isn’t enough.
- Complete and sign Form W-7. Enter “N/A” where a line does not apply rather than leaving it blank. For a non-resident founder filing a personal return, the usual reason is box b, “Nonresident alien filing a U.S. federal tax return.” Add the tax ID issued by your country of tax residence on line 6b, if you have one.
- Prepare the return it belongs to. For a founder with effectively connected income, that is usually Form 1040-NR. Attach Form W-7 to the front and leave the SSN field blank for each ITIN applicant. The IRS assigns the number and processes the return. You can apply without a return only under a documented exception in the Form W-7 instructions, such as certain third-party withholding or treaty claims. Include the evidence that exception requires.
- Gather identity documents. For an adult founder applying on their own behalf, a valid passport proves both identity and foreign status on its own. Without one, submit at least two document types from the IRS list of 13 accepted documents that together prove both, with at least one photo. Documents must be current. Send originals or copies certified by the issuing agency, not plain photocopies. Dependent applications have additional rules.
- Send the package, or use an acceptance agent. By postal mail: Internal Revenue Service, ITIN Operation, P.O. Box 149342, Austin, TX 78714-9342. By private courier: Internal Revenue Service, ITIN Operation, Mail Stop 6090-AUSC, 3651 S. Interregional, Hwy 35, Austin, TX 78741-0000. Use this ITIN address, not the normal Form 1040-NR address. A Certifying Acceptance Agent (CAA) can authenticate a founder’s passport and return it immediately, in the US or abroad. A regular Acceptance Agent helps prepare the package but must forward originals or issuing-agency-certified copies. Designated IRS Taxpayer Assistance Centers offer in-person document verification by appointment; some VITA sites also help with applications.
- Plan around the timeline. Allow 7 weeks for an IRS status notice, or 9–11 weeks during peak processing (January 15 through April 30) or when applying from outside the US. Original documents are returned to the mailing address on Form W-7. Contact the IRS if they haven’t come back within 60 days. If you’ll need your passport sooner, consider a CAA rather than mailing it.
The IRS publishes the full route on its How to apply for an ITIN page, and the line-by-line detail in the Instructions for Form W-7 (checked October 2026).
If you mail original documents to the IRS, expect them back within 60 days. Using a Certifying Acceptance Agent avoids that entirely — they authenticate your documents in person and hand them straight back.
Frequently asked questions
How do I apply for an ITIN from outside the US?
Complete Form W-7, attach it to the federal return it belongs to (usually Form 1040-NR), and either mail the package to the IRS Austin ITIN Operation or use a Certifying Acceptance Agent abroad, who authenticates your passport and forwards the application for you. Allow 9–11 weeks when applying from outside the US.
How long does an ITIN application take?
About 7 weeks in a normal period. During tax season (mid-January to the end of April) or when you apply from outside the US, allow 9–11 weeks.
Do I need an ITIN to form an LLC or get an EIN?
No. A foreign owner who is not eligible for an SSN or ITIN can form an LLC and apply for its EIN without one. An ITIN serves your personal federal tax purpose, such as filing Form 1040-NR, claiming a treaty benefit, or meeting a documented Form W-7 exception.
Can I apply for an ITIN without a tax return?
Only under the specific documented exceptions in the Form W-7 instructions, such as certain third-party withholding or treaty claims. In the standard case, Form W-7 goes in attached to the return it is needed for.
What happens after I apply?
The IRS mails a CP565 notice when your ITIN is assigned, a CP566 if it needs more information, or a CP567 if the application is rejected. Follow the notice’s instructions before resubmitting. Contact the IRS if mailed original documents haven’t been returned within 60 days.
We don’t file ITIN applications on a client’s behalf, but we can point you to the IRS’s own guidance and its list of authorized Certifying Acceptance Agents so you can choose the route that fits you. When we prepare your federal tax return and you need an ITIN attached to it, we’ll flag exactly what Form W-7 and its supporting documents require.
How long it takes, and what the IRS sends back
Standard processing runs about 7 weeks; expect 9–11 weeks if you’re applying during tax season (January–April) or from outside the US. Along the way, you may hear from the IRS directly:
| Notice | Meaning | What to do |
|---|---|---|
| CP565 | ITIN assigned | Nothing — keep it for your records |
| CP566 | More information needed | Respond with the requested documents |
| CP567 | Application rejected | Resubmit with corrections |
Tax benefits an ITIN unlocks — and what it doesn’t
An ITIN comes with real limits, but it also opens up several benefits: joint filing with a US citizen or resident spouse, Head of Household status, the American Opportunity Tax Credit, the Premium Tax Credit, and the Credit for Other Dependents.
It doesn’t get you Social Security benefits (even on contributions you’ve made), the Earned Income Tax Credit, or the Child Tax Credit — a 2025 update to federal tax law made permanent the requirement that a qualifying child have a Social Security Number, so ITIN-only dependents still don’t qualify for the CTC. That’s a durable rule now, not a temporary one set to expire.
ITINs expire — here’s when and how to renew
ITINs aren’t permanent. Yours expires under either of two conditions:
- Three years of non-use — if it hasn’t appeared on a federal return for three consecutive years, it expires on December 31 of the third year.
- Middle-digit expiration — ITINs with middle digits 70–88, or 90–92 and 94–99 issued before 2013, have already expired.
Filing with an expired ITIN doesn’t stop your return from being accepted, but the IRS holds your refund and any credits you’d otherwise qualify for until you renew — which can mean real delays if you’re depending on that refund.
Renewing works exactly like applying for a new ITIN: complete Form W-7, check the “renew” box, enter your expired ITIN, and attach your current year’s return along with current identity documents.
Start renewing at least 45 days before you file. And if your ITIN only ever shows up on information returns like a 1099, you don’t need to renew it unless you’re actually filing a tax return.
Using your ITIN for business
Bank requirements vary by provider — some banks ask for an SSN or ITIN before opening a business account, others accept alternative documentation, and policies can differ by branch or by whether the account is opened in person or online. It’s worth checking directly with the bank you’re considering rather than assuming you need an ITIN first. If a bank does require one, having it ready removes that bottleneck right after forming your LLC, alongside your bookkeeping.
FinCEN BOI reporting is separate from an ITIN. Under FinCEN’s final rule, effective August 14, 2026, companies formed in the US, including foreign-owned LLCs, are exempt. A company formed outside the US may need to report if it separately registers to do business in a US state or tribal jurisdiction and no exemption applies. Simply owning a US LLC does not create that registration or make the LLC subject to BOI reporting. Existing foreign reporting companies generally had to file by April 25, 2025; those registered on or after March 26, 2025 have 30 calendar days from notice of effective registration.
What an ITIN does — and doesn’t — share
Section 6103 of the tax code protects your ITIN information from routine sharing with other government agencies for non-tax purposes — the IRS built the ITIN specifically to be a tax tool, not an enforcement one. Data-sharing rules between federal agencies do shift over time and have been the subject of legal challenges in recent years; if this is a live concern for your situation, it’s worth checking current IRS guidance or talking with an immigration attorney rather than relying on any single summary. For the vast majority of ITIN holders, the ITIN remains what it was built to be: a way to meet a tax obligation.
Moving from ITIN to SSN
If you later become SSN-eligible — a green card or work visa, for example — stop using your ITIN and notify the IRS so your records merge under the new number. Mail the IRS your name, address, ITIN, a copy of your CP565 notice, and a copy of your new Social Security card; the IRS voids the ITIN and transfers your tax history to the SSN. Skipping this step can cost you credit for wages and withholding that should already be on record.
A quick founder checklist
- Confirm you actually have a federal tax purpose first — an ITIN isn’t needed to form an LLC or get an EIN.
- A valid passport is the fastest path if you do need one — it’s the only document that works alone.
- Apply or renew at least 45 days before you need to file.
- Consider a Certifying Acceptance Agent if you’d rather not mail your passport.
- Track your ITIN’s expiration: three years of non-use, or an already-expired middle-digit range.
- Notify the IRS the moment you become SSN-eligible.
None of this needs to be confusing. When we prepare your federal tax return and an ITIN turns out to be part of your filing, we’ll flag exactly what’s needed and point you to the IRS’s own Form W-7 process and its list of Certifying Acceptance Agents — for anything more involved, reach out and we’ll help you figure out the right path.
