How to Get an ITIN as a Non-US Resident (2026 Guide)

If you are a non-US resident earning income from a US business, you will sooner or later run into three little letters: ITIN. An ITIN (Individual Taxpayer Identification Number) lets you meet US tax obligations even though you do not have — and cannot get — a Social Security Number. This 2026 guide explains exactly what an ITIN is, who needs one, and how to apply step by step.

What is an ITIN?

An ITIN is a 9-digit tax processing number issued by the IRS to people who must file or be reported on a US tax return but are not eligible for a Social Security Number (SSN). It always begins with the number 9. An ITIN is used only for federal tax purposes — it does not grant work authorization, immigration status, or eligibility for benefits.

ITIN vs SSN vs EIN — what is the difference?

• SSN — issued to US citizens and residents authorized to work. Most non-residents cannot get one.
• EIN — a tax ID for your business (your LLC or corporation). You need it to open a US bank account and file business taxes. Learn more in our guide on how to get an EIN as a non-resident.
• ITIN — a tax ID for you as an individual, used when you personally need to file a US return or be reported on one.

Who needs an ITIN?

You likely need an ITIN if you are a non-resident who:

• Must file a US federal tax return (for example, a US-source income filing).
• Owns a US LLC or corporation that creates a personal US filing requirement.
• Needs to claim a tax treaty benefit or a refund of over-withheld US tax.
• Is listed as a partner, owner, or beneficiary on a US return.

Not every non-resident business owner needs an ITIN — many only need an EIN for the company. The right answer depends on how your income is taxed, so it is worth confirming before you apply.

Documents you need (Form W-7)

An ITIN application is made on IRS Form W-7. You will typically need:

• A completed and signed Form W-7.
• A valid passport (the single best stand-alone identity document) or two alternative IDs.
• The US tax return the ITIN is being requested for, unless you qualify for an exception.
• Supporting documents for any tax treaty or exception you are claiming.

How to apply: step by step

1. Confirm you actually need one. Match your situation to a valid W-7 reason code.
2. Complete Form W-7 accurately — small errors here are the #1 cause of rejection.
3. Prepare your identity documents. Originals or certified copies are required; a Certifying Acceptance Agent (CAA) can verify your passport so you do not have to mail it.
4. Attach your federal tax return (or your exception documentation).
5. Submit to the IRS by mail, through a CAA, or at an IRS Taxpayer Assistance Center.

How long does an ITIN take?

Processing usually takes around 7 to 11 weeks, and longer during peak tax season (January to April). Applying through a Certifying Acceptance Agent can reduce errors and avoid mailing your original passport.

Common mistakes to avoid

• Applying for an ITIN when you only needed an EIN for the business.
• Sending uncertified photocopies of your passport.
• Choosing the wrong reason code on Form W-7.
• Forgetting to attach the tax return when one is required.

Frequently asked questions

Can I get an ITIN without a US visit?

Yes. Most non-residents apply entirely by mail or through a Certifying Acceptance Agent without travelling to the US.

Does an ITIN expire?

Yes — an ITIN can expire if it is not used on a US tax return for three consecutive years, after which it must be renewed.

Do I need both an EIN and an ITIN?

Often you only need an EIN for your company. You add an ITIN only when you personally have a US filing requirement. We will tell you which one your situation actually calls for.

Get your ITIN handled for you

3Companion has helped over 10,000 clients across 150+ countries with US tax IDs, company formation, and compliance — 100% remotely. We will confirm whether you need an ITIN, an EIN, or both, then prepare and file everything for you. Start your application here or message us on WhatsApp for a free consultation. New to US companies? Begin with our company registration in USA guide or learn more about 3Companion.