Verified against official sources — 31 Oct 2026
ITIN Explained: Who Needs an Individual Taxpayer Identification Number and How to Apply
NEW Published 31 October 2026
The tax number for people who need one but cannot have a Social Security number — who it is for, what it never does, and how W-7 works.
An ITIN is a nine-digit, IRS-issued tax processing number for people who need a U.S. taxpayer identification number for federal tax purposes but are not eligible for a Social Security number. It is for taxes only: it does not authorise work, does not change immigration status, and does not qualify anyone for Social Security benefits. You apply on Form W-7, normally attached to the federal tax return that creates the need, with a passport (the only stand-alone document) or two others. Apply by mail, in person at an IRS Taxpayer Assistance Center, or through an IRS-approved acceptance agent; the IRS says to allow seven weeks for a decision — nine to eleven in tax season. An ITIN unused on a federal tax return for three consecutive tax years expires on 31 December after the third year of non-use and must be renewed before use on a return again. If you are eligible for an SSN, get an SSN instead — you cannot hold both numbers.
SECTION 01What an ITIN Is: A Tax Number, Nothing More
RULE — The definition, in the IRS's own terms. An ITIN is a nine-digit number issued by the IRS to individuals who are required, for U.S. federal tax purposes, to have a U.S. taxpayer identification number but who do not have, and are not eligible to get, a Social Security number. Both halves matter: there must be a federal tax purpose, and the person must be outside the SSN system. Without the tax purpose, there is no application; with SSN eligibility, this is the wrong form (Section 04).
RULE — It exists to let the IRS process a person's taxes. The IRS writes the assigned ITIN onto your tax return and forwards it for processing; the number is how filings, payments and refunds attach to someone who has no SSN. It is issued regardless of immigration status — the IRS states that resident aliens, nonresident aliens and their spouses and dependents can apply regardless of immigration status.
SECTION 02What an ITIN Is Not: The Four Limits
The IRS publishes the limits as a list; they answer the questions families most often get wrong:
Not work authorisation
- RULE — An ITIN doesn't authorise you to work legally in the U.S. A job still requires its own employment authorisation; the number changes nothing about the right to work.
Not an immigration status
- RULE — An ITIN doesn't provide or change immigration status. Holding one neither grants nor evidences lawful presence; it is a tax record.
Not Social Security
- RULE — An ITIN doesn't qualify you for Social Security benefits or the Earned Income Tax Credit. The W-7 instructions add that a child with an ITIN cannot be counted as a qualifying child for that credit either.
Not general ID
- RULE — An ITIN doesn't serve as identification outside the federal tax system. It is issued for federal tax purposes only; other agencies run identity checks.
SECTION 03Who Needs an ITIN: The Federal Tax Purpose Test
RULE — You need an ITIN if you have a federal tax purpose and are not eligible for an SSN. The IRS defines a federal tax purpose as: being legally required to file a U.S. federal income tax return; wanting to claim a refund or an allowable tax benefit, or report income, by filing a return; being claimable as a spouse or dependent for an allowable tax benefit; or having to provide a taxpayer identification number for another federal tax purpose. A return with all-zero entries does not create one — the need must be real.
RULE — The situations the IRS lists. You may need an ITIN if you are: a nonresident alien claiming a tax treaty benefit; a nonresident or resident alien filing a U.S. federal tax return; a dependent or spouse of a U.S. citizen or resident alien; a nonresident alien student, professor or researcher filing a return or claiming an exception; or a dependent or spouse of a nonresident alien visa holder. That last category is the one most families here meet: the worker has an SSN through employment, while the spouse or children — with no work authorisation of their own — need ITINs to appear on the family's return.
RULE — Spouses and dependents face a narrower gate. A spouse or dependent is eligible only if they can be claimed for an allowable tax benefit (such as a joint return, head of household status, or one of the dependent credits the IRS names) or if they file their own tax return. The W-7 instructions repeat the point — including for renewals — and require the person to be listed on the attached return with the relevant schedule or box completed.
SECTION 04Who Should Not Apply: If You Can Get an SSN, Get an SSN
RULE — Form W-7 is closed to anyone who has, or could get, an SSN. The Form W-7 instructions state it plainly: do not complete Form W-7 if you have an SSN or if you are eligible to get one. The IRS's ITIN page lists who does not qualify on the same basis — U.S. citizens, permanent residents, anyone eligible for an SSN, and specifically a nonresident alien with a U.S. work visa, since that person qualifies for an SSN. The instructions define the eligibility line: you are eligible for an SSN if you are a U.S. citizen or admitted for permanent residence or for U.S. employment.
RULE — Two sequencing details from the instructions. If you have an application for an SSN pending, do not file Form W-7. And if the Social Security Administration determines you are not eligible for an SSN, complete Form W-7 only after that decision — you must obtain the SSA's denial letter and attach it. Who qualifies for an SSN and how the card is issued are covered in our Social Security number guide, linked below; for anyone with U.S. employment authorisation, that guide is the correct starting point.
SECTION 05The Application Package: Form W-7 Plus the Return That Needs It
RULE — Timing: the W-7 travels with the return, not after it. Apply on or before your tax return's due date, include the return in the package, and do not file the return separately. You can apply at any time for a prior-year return, or if you meet one of the exceptions to the tax-return requirement described in the W-7 instructions. For credits, the timing has teeth: you, your spouse and your dependents must have ITINs assigned by the return's due date (including extensions) to be eligible to claim certain credits.
RULE — Two things you do not need an ITIN for. Requesting extra time: file Form 4868 by the April filing date, write "ITIN TO BE REQUESTED" where the form asks for an SSN or ITIN, with no W-7 attached. Making estimated tax payments: use the Form 1040-ES or 1040-ES (NR) voucher with the same notation, again without a W-7.
SECTION 06Documents: A Passport, or Two Others
RULE — Documents must prove identity and foreign status, be current, and be originals or certified copies. The IRS accepts 13 supporting documents. A certified copy is an exact copy provided and certified by the original issuing agency, bearing its official stamped seal — the IRS does not accept notarised documents instead.
RULE — A passport is the only stand-alone document. Submit an original valid passport (or a certified copy), and no other supporting document is needed: it proves both identity and foreign status on its own. Without a passport, you submit two documents — one proving identity, another proving foreign status — and one must show your photograph. The IRS's lists include, among others, a U.S. Department of State visa, a national identification card, a foreign driver's licence and a civil birth certificate as combined identity/status evidence, and a U.S. driver's licence or state ID as identity-only.
RULE — Dependents need one more layer: proof of U.S. residency. A dependent claimed for an allowable tax benefit must also prove U.S. residency, with limited exceptions (dependents from Canada or Mexico in some cases, and dependents of U.S. military personnel stationed overseas). A passport showing a U.S. date of entry can serve as that proof; otherwise, check the IRS's supporting-documents page for the U.S. records it accepts for dependents. Dependents under 18 without a valid passport must also submit an original civil birth certificate.
SECTION 07Three Ways to Apply: Mail, In Person, or an Acceptance Agent
To the IRS ITIN Operation
- RULE — Mail the whole package — W-7(s), tax return and documents — to the IRS ITIN Operation in Austin, Texas (current postal and courier addresses are on the IRS's apply-for-an-ITIN page and in the W-7 instructions).
- RULE — Original documents come back by mail: the IRS returns them to the mailing address on line 2 of your Form W-7, within 60 days.
IRS Taxpayer Assistance Centers and VITA sites
- RULE — Designated Taxpayer Assistance Centers with ITIN services review your completed W-7, authenticate most documents, hand them back at the end of the appointment and forward the package. The IRS lists this route as free; appointments can take several weeks. Selected VITA sites offer the same service, also free, at limited locations.
IRS-approved agents, in the U.S. and abroad
- RULE — Certifying Acceptance Agents (CAAs) can complete and review the W-7, authenticate most documents and return them at the appointment, and deal with the IRS on application issues. Ordinary Acceptance Agents help complete and submit the package but cannot authenticate documents — originals still go to the IRS. The IRS lists both agent routes as fee-based and says fees may vary: agents set their own charges.
ADVICE — Choose the route by your documents, not by habit. If you cannot be without your passport for up to 60 days, mail certified copies instead of the original, or use an in-person route where documents are authenticated and handed back. Note two authentication gaps the IRS flags: Taxpayer Assistance Centers cannot authenticate school and medical records for dependents — those must be mailed with the package — and CAAs cannot authenticate dependent documents other than passports and birth certificates.
SECTION 08After You Apply: Seven Weeks, and Three Possible Notices
RULE — Allow seven weeks for the IRS to notify you. The IRS's own processing statement: allow seven weeks for notification of your application status, rising to nine to eleven weeks in tax season (15 January to 30 April) or if you applied from overseas. If no notice arrives in that window, the IRS tells applicants to contact it; the same applies if mailed originals have not come back within 60 days.
RULE — The answer arrives as a CP notice, and there are three kinds. A CP565 notice means an ITIN has been assigned — no further action needed. A CP566 notice means the IRS needs more information. A CP567 notice means the application was rejected and must be resubmitted. Keep the CP565 safe: it is your proof of the number, and if you later become eligible for an SSN, the IRS asks for a copy when your tax records are combined under the SSN (Section 09).
SECTION 09Expiry and Renewal: The Three-Year Rule
RULE — An unused ITIN expires. If an ITIN is not used on a U.S. federal tax return for any three consecutive tax years, it expires on 31 December after the third tax year of non-use. The W-7 instructions add a legacy case: an ITIN assigned before 2013 that was never renewed also needs a renewal application, filed with a return. An expired ITIN is not deleted — it cannot be used on a return until renewed.
RULE — Renew only when the number will appear on a return. You must renew an expired ITIN if it will be included on a U.S. federal tax return. If the ITIN is only used on information returns that report payments you receive — Form 1099 is the IRS's example — you do not need to renew; expired ITINs may continue to be used there. Filing a return with an expired ITIN has consequences the IRS names: processing may be delayed, certain credits may be unavailable until renewal, and the result can be a reduced refund or penalties and interest.
RULE — Renewal is the same form, marked as a renewal. Complete Form W-7 following the normal application steps: check the "Renew an existing ITIN" box, check the reason box that applies, and in lines 6e and 6f enter your existing ITIN and the name it was issued under. Renewals include a U.S. federal tax return unless an exception applies, and spouses and dependents renewing for a benefit must be listed on that return with the benefit's form or schedule. If your legal name has changed since the ITIN was issued, include documentation of the change, such as a marriage certificate or court order.
RULE — If an SSN replaces your ITIN, the ITIN is retired. You cannot have both an ITIN and an SSN. Once you are issued an SSN: stop using the ITIN, use the SSN for tax purposes, and notify the IRS, which combines your tax records under the SSN and voids the ITIN. The IRS warns that skipping the notification can cost you credit for wages paid and taxes withheld, and reduce any refund due. And do not renew an ITIN if you have received an SSN.
FAQFrequently Asked Questions
Does an ITIN let me work legally in the United States?
No. The IRS states it directly: an ITIN doesn't authorise you to work legally in the U.S., doesn't provide or change immigration status, and doesn't qualify you for Social Security benefits or the Earned Income Tax Credit. It exists for federal tax purposes only. Work authorisation comes from your immigration status and, where required, a separate employment authorisation.
My spouse has no work authorisation. Should they apply for an ITIN or an SSN?
An ITIN — if the family has a federal tax purpose for one. Form W-7 is closed to anyone eligible for an SSN, and the W-7 instructions define SSN eligibility as being a U.S. citizen or admitted for permanent residence or U.S. employment. A spouse not admitted for employment is not SSN-eligible on that basis, so the ITIN is the route — provided they will be claimed for an allowable tax benefit or file their own return. If your spouse later gains employment authorisation, the position flips: they apply for an SSN, stop using the ITIN, and notify the IRS so the records combine.
How long does an ITIN application take, and what does the IRS charge?
The IRS says to allow seven weeks for notification, or nine to eleven weeks in tax season (15 January to 30 April) or when applying from overseas. On cost, the IRS's own comparison is the accurate guide: its table lists a Taxpayer Assistance Center or a VITA site as free, and acceptance agents as fee-based — agents set their own service charges, and the IRS says fees may vary.
I need to file on time but my ITIN application is not ready. What do I do?
File for the time, not the number. The IRS confirms you do not need an ITIN to request an extension or make estimated payments: submit Form 4868 by the April filing date with "ITIN TO BE REQUESTED" written where an SSN or ITIN is requested — and no W-7 attached. The W-7 belongs with the tax return itself, on or before its due date including extensions.
My ITIN expired. Has the number been given to someone else, and do I get a new one?
No — expiry is about use, not reassignment. An ITIN unused on a federal tax return for three consecutive tax years expires on 31 December after the third year of non-use. Renewal reactivates the same number: on Form W-7 you check "Renew an existing ITIN" and enter your ITIN and the name it was issued under in lines 6e and 6f. Renew only if the number will be included on a federal tax return; if it appears only on information returns such as a Form 1099, renewal is not required.
Official references and verification status
These official references were accessed and checked on 31 October 2026, and this guide's RULE items were verified claim-by-claim against them (record in the accompanying .sources.md file). All sources are irs.gov, per this guide's scope. Two deliberate handlings. First, cost: the fetched IRS text nowhere prints an application fee for Form W-7 itself, and nowhere states one is waived — so this guide prints no IRS fee claim either way, and reports only what the IRS's route comparison says (its in-person channels listed as free; acceptance agents fee-based with varying fees). Second, older ITIN expiry waves: the IRS's current renewal guidance states only the three-year rule and the pre-2013 never-renewed case, so no middle-digit expiry schedule is printed — it is not in the IRS text checked here.
- IRS — Individual Taxpayer Identification Number (ITIN)
- IRS — About Form W-7, Application for IRS Individual Taxpayer Identification Number
- IRS — How to Apply for an ITIN
- IRS — How to Renew an ITIN
- IRS — ITIN Supporting Documents
- IRS — Instructions for Form W-7 (Rev. December 2024)
General educational information, not individualized tax or legal advice. Consult a tax professional for your case.
General information only. This guide is based on official sources publicly available and checked on the date shown on this page. Visa rules change, and consular and USCIS officers decide every case on its own facts — nothing here is a confirmation or a guarantee for your individual case, and this is not legal advice. Always confirm the current requirement on the official page linked in this guide before you act, and consider a qualified immigration attorney for your specific situation.