ITIN Number: Who Needs One and How to Apply (2026)
An ITIN (Individual Taxpayer Identification Number) is a nine-digit number the IRS issues to people who have a U.S. federal tax purpose but are not eligible for a Social Security number. A founder who has just incorporated in Delaware, an investor who owns U.S. real estate, a family filing a joint return, a student claiming a treaty benefit — all of them may need one. This guide explains what an ITIN is, what it emphatically is not, and how the application actually works.
What an ITIN does and does not do
An ITIN is issued for federal tax purposes only. Knowing the edges of that sentence prevents a lot of false expectations. In the IRS’s own words, an ITIN does not:
- Qualify you for Social Security benefits or the Earned Income Tax Credit.
- Provide or change immigration status.
- Authorize you to work legally in the U.S.
- Serve as identification outside the federal tax system.
What it does do is let you file a return, claim a refund, claim certain allowable tax benefits, and rely on a tax treaty provision. In practice some institutions also ask for one when opening an account — but that does not make an ITIN an identity document.
Who needs one and who does not
The test is simple: you need an ITIN if you have a federal tax purpose and you are not eligible for an SSN. You have a federal tax purpose when you are legally required to file a U.S. federal income tax return; when you want to claim a refund or an allowable tax benefit or report income by filing a return; when you can be claimed as a spouse or dependent for an allowable tax benefit; or when you must provide a tax identification number for another federal tax purpose.
Immigration status does not determine eligibility. Resident aliens, nonresident aliens, and their spouses or dependents may apply regardless of status.
Who does not need one is equally clear: U.S. citizens, nonresident aliens holding a U.S. work visa (who therefore qualify for an SSN), lawful permanent residents, and anyone else eligible for an SSN. Applying for an ITIN when you could obtain an SSN only slows your file down.
The application package: three parts
An ITIN application package has three components, and most rejections trace back to one of them being wrong.
| Component | What is required |
|---|---|
| 1. Form W-7 | A separate form for every applicant. In family filings each person completes their own W-7. For a renewal, complete the renewal sections of the form. |
| 2. Federal tax return | Form 1040 or Form 1040-NR. Leave the SSN field blank for every ITIN applicant; the IRS writes in the assigned number. Attach spouses’ and dependents’ W-7s to the front of the return. |
| 3. Supporting documents | Proof of foreign status and identity, plus proof of U.S. residency for dependents. |
There are exceptions to the return requirement — certain treaty claims and information-reporting situations among them — and they are listed in the Form W-7 instructions. If you meet an exception, you can apply at any time of year without a return. The same flexibility applies if you are filing a prior-year return.
Do not mail your passport: four ways to apply
The most common mistake is mailing an original passport to the ITIN Operation in Austin. It is permitted, but your documents are gone for weeks. The IRS offers three routes that authenticate most documents and hand them back at the end of the appointment.
| Option | Cost | Authenticates documents? | Where |
|---|---|---|---|
| IRS Taxpayer Assistance Center (with ITIN services) | Free | Yes, most | U.S. |
| VITA site (with ITIN services) | Free | Yes, most | Limited U.S. locations |
| Certifying Acceptance Agent (CAA) | Fee-based | Yes, most | U.S. and international |
| Acceptance Agent (AA) | Fee-based | No | U.S. and international |
| By mail (Austin ITIN Operation) | Free | — | Anywhere |
A few distinctions matter. A Taxpayer Assistance Center can authenticate all documents for applicants who appear in person except school and medical records for dependents, which must be mailed with the package. CAAs — including those at VITA sites — cannot authenticate foreign military ID cards, or documents for dependents other than passports and birth certificates. And the sharpest distinction of all is between an Acceptance Agent and a Certifying Acceptance Agent: only the certifying one authenticates documents.
There is no IRS fee for Form W-7. CAA and AA services are private services and their fees vary.
Timing, notices and expiration
The IRS asks you to allow 7 weeks for notification of your application status. That stretches to 9–11 weeks during tax season (January 15 to April 30) or if you applied from overseas. Supporting documents sent by mail are returned to the address on line 2 of your Form W-7 within 60 days.
Read the notice you receive carefully: CP565 means the ITIN was assigned, CP566 means the IRS needs more information, and CP567 means the application was rejected and must be resubmitted.
An ITIN is not permanent. One that has not appeared on a U.S. federal tax return for three consecutive tax years expires on December 31 of that third year. Separately, ITINs with middle digits 70 through 88 have all expired. Renewal is done through the renewal sections of Form W-7, and the IRS recommends submitting it at least 45 days before you need to file.
One point deserves emphasis. For the child tax credit, the credit for other dependents, and the American opportunity tax credit, the number must be assigned by the due date of the return, including extensions. Applying late is not merely a delay — it can mean losing a credit outright.
For founders forming a U.S. company
For founders expanding into the U.S., the sequence is usually: form the entity, obtain an EIN, open a bank account, and then discover at the personal filing stage that an ITIN is required. Three misunderstandings recur.
- An ITIN is not an EIN. An EIN belongs to the business and is obtained through a separate process. An ITIN belongs to the individual.
- An ITIN is not work authorization. Drawing a salary from your own U.S. company requires an appropriate visa status; an ITIN does not fill that gap.
- The entity’s filings are not the end of it. In foreign-owned structures, the company’s own reporting obligations sit alongside the owner’s personal position, which must be assessed separately.
The worst version of this in practice is remembering the ITIN a few weeks before a filing deadline. The right approach is to build the formation calendar and the tax calendar together from the start.
Frequently asked questions
Can I work in the U.S. with an ITIN?
No. An ITIN does not authorize employment and does not provide immigration status. It exists for federal tax purposes only.
I received an SSN. What happens to my ITIN?
You cannot hold both. Once you have an SSN, stop using the ITIN and notify the IRS so your tax records are combined. If you do not, you may not receive credit for all wages paid and taxes withheld, which can reduce a refund.
Can I get a filing extension without an ITIN?
Yes. No ITIN is needed to request an extension. Mail Form 4868 by the April due date and write “ITIN TO BE REQUESTED” in the SSN or ITIN fields. Do not attach a W-7 to Form 4868. The extension covers filing only — any tax owed is still due in April.
Can I apply from outside the United States?
Yes. You can mail the package or work with a Certifying Acceptance Agent operating internationally. Note that applications from overseas fall into the 9–11 week notification window, so plan accordingly.
What to do now
- Check SSN eligibility first — If you can obtain an SSN, do not apply for an ITIN.
- Work backward from the filing deadline — Tax season pushes the wait to 9–11 weeks, and credit eligibility turns on that date.
- Avoid mailing your original passport — A TAC, a VITA site, or a Certifying Acceptance Agent can hand it back the same day.
- Confirm the word “Certifying” — Only a Certifying Acceptance Agent authenticates documents; a plain Acceptance Agent does not.
- Complete a separate form per family member — Every applicant needs their own W-7.
- Set a renewal reminder — Three unused consecutive years and the number expires, a frequent cause of refund delays.
Founding attorney of Ozek Law Firm, LLC. Admitted in Maryland, New York and Washington, D.C., he advises individuals, families and companies on immigration and business law.
We sequence formation, EIN, ITIN and the first return together — and make sure you choose the right filing route before any documents leave your hands.
This page is for general information only and does not constitute legal or tax advice. Attorney Advertising. Information is current as of Sept. 14, 2026. IRS procedures, form editions, processing times and expiration schedules change; verify at irs.gov/itin and in the current Form W-7 instructions before applying. Tax situations are individual; consult your attorney and tax adviser about your own circumstances.
Ozek Law Firm, LLC · 4500 East West Highway, Suite 150, Bethesda, MD 20814 · +1 (202) 854-8545 · info@ozeklaw.com · www.ozeklaw.com
Admitted in Maryland, New York and Washington, D.C.; federal immigration practice nationwide. Consultations available in Turkish, English, Spanish and Swedish.
