Updated October 17, 2026. Quick answer: Form W-7 is the Application for IRS Individual Taxpayer Identification Number. The form says not to submit it if you have, or are eligible to get, a U.S. social security number. The decision is whether an ITIN is the right number at all, and if so, which reason box in a to h describes the application.
More IRS forms and schedules, read line by line: Form SS-5 instructions and Form 1040-NR nonresident return.
ITIN or SSN: who uses Form W-7
The instructions define the number: “An ITIN is a nine-digit number issued by the IRS to individuals who are required for federal tax purposes to have a U.S. taxpayer identification number but who don’t have and aren’t eligible to get a social security number (SSN).” The form’s own first caution says “Don’t submit this form if you have, or are eligible to get, a U.S. social security number (SSN).”
The instructions explain who is eligible for an SSN: “You’re eligible for an SSN if you’re a U.S. citizen or if you’ve been admitted by the United States for permanent residence or U.S. employment.” A pending application also matters: “If you have an application for an SSN pending, don’t file Form W-7.” “Complete Form W-7 only if the SSA notifies you that you’re ineligible for an SSN.”
The number has a stated scope. The form says an ITIN “is for U.S. federal tax purposes only.” The instructions add that an ITIN “doesn’t entitle you to social security benefits”. Once an SSN arrives, “An ITIN will not be issued to you once you have been issued an SSN.”
The reasons for applying, boxes a to h
The form asks for a reason and warns about the return: “If you check box b, c, d, e, f, or g, you must file a U.S. federal tax return with Form W-7 unless you meet one of the exceptions (see instructions).” Where more than one reason fits, “If more than one box applies to you, check the box that best explains your reason for submitting Form W-7.”
| Box | As printed on the form |
|---|---|
| a | “Nonresident alien required to get an ITIN to claim tax treaty benefit (you must also check and complete box h (see instructions))” |
| b | “Nonresident alien filing a U.S. federal tax return” |
| c | “U.S. resident alien (based on days present in the United States) filing a U.S. federal tax return” |
| d | “Dependent of U.S. citizen/resident alien” |
| e | “Spouse of U.S. citizen/resident alien” |
| f | “Nonresident alien student, professor, or researcher filing a U.S. federal tax return or claiming an exception (if claiming an exception, you must also check and complete box h (see instructions))” |
| g | “Dependent/spouse of a nonresident alien holding a U.S. visa” |
| h | “Other (see instructions)” |
Box d and box e carry extra entries. For box d, “you must provide the relationship (for example, parent, child, grandchild, etc.) of the dependent to the U.S. citizen/resident alien.” Box c is the day-count reason. The instructions describe a foreign individual living or present in the United States for a certain number of days (the substantial presence test) who doesn’t have permission to work from the USCIS and is ineligible for an SSN: “These individuals must check this box and include a date of entry into the United States on line 6d.”
Treaty benefits, passive income and dependents
For the treaty reason, the instructions say “Certain nonresident aliens must get an ITIN to claim certain tax treaty benefits even if they don’t have to file a U.S. federal tax return.” That reason is paired with another box: “If you check this box to claim the benefits of a U.S. income tax treaty with a foreign country, you must also check box h.”
Box h is the catch-all: “If the reason for your ITIN request isn’t described in boxes a through g, check this box.” One listed exception covers passive income: “This exception may apply if you’re the recipient of partnership income, interest income, annuity income, rental income, or other passive income”. The instructions list information returns that may apply, including “Form 1042-S, Foreign Person’s U.S. Source Income Subject to Withholding”. The same passage limits the exception: “If you’re required to file a federal tax return, then you aren’t eligible for Exception 1.”
For spouses and dependents, the instructions print a filter: “For tax years after December 31, 2017, spouses and dependents are NOT eligible for an ITIN or to renew an ITIN unless they are claimed for an allowable tax benefit or they file their own tax return.” The allowable benefits begin with “A spouse filing a joint return,” and include “Head of household (HOH),” “Child and dependent care credit (CDCC), or” “Credit for other dependents (ODC).”
Documents and the numbers they carry
The documentation rules start with originals: “You must submit original documents, or certified copies of these documents from the issuing agency, that support the information provided on Form W-7.” They also must be “current (that is, not expired at the time you submit your application).”
The instructions count the acceptable documents: “There are 13 acceptable documents, as shown in the following table.” A passport can stand alone: “If you submit an original valid passport or a certified copy from the issuing agency, you don’t need to submit any other documents from the table.”
| Item | As printed in the instructions |
|---|---|
| Photograph | “At least one document must contain your photograph, unless you’re a dependent under age 14 (under age 18 if a student).” |
| Medical records | “Medical records (accepted only for dependents under 6 years of age).” |
| Date of medical care | “Date of medical care within 12 months before the date of the Form W-7 application” |
| School records | “School records (accepted only for dependents under 24 years of age).” |
| School term dates | “School term dates ending no more than 12 months from the date of the Form W-7 application” |
| Original documents | “If your original documents aren’t returned within 60 days, you can call the IRS” |
The documents can be returned to the applicant, since “Original documents you submit will be returned to you at the mailing address shown on your Form W-7.”
Where to apply, timing and expiry
The instructions list in-person and agent routes. “You can also apply through one of the two types of acceptance agents authorized by the IRS.” “Note. AAs and CAAs are available both domestically and abroad.” About certifying acceptance agents: “A CAA can verify original documentation and certified copies of the documentation from the issuing agency for primary and secondary applicants and their dependents, except for foreign military identification cards.” “The CAA will return the documentation immediately after reviewing its authenticity.”
A first application travels with the return: “If you’re applying for a new ITIN, complete and attach Form W-7 to the front of your tax return and file your application package with your tax return for which the ITIN is needed on or before the due date for the return.” On e-filing, “You can’t electronically file (e-file) a return using an ITIN in the calendar year the ITIN is assigned.”
Timing and expiry are printed as follows. “Allow 7 weeks for the IRS to notify you of your ITIN application status”. For renewal, “An ITIN only needs to be renewed if it’ll be included on a U.S. federal tax return and it’s expired.” On expiry, “If your ITIN wasn’t included on at least one U.S. federal tax return for the last 3 consecutive tax years, it expires on December 31 of the third consecutive tax year, and must be renewed before being used again on a U.S. federal tax return.”
For the IRS pointer page on the number itself, see the IRS page on individual taxpayer identification numbers.
Which revision applies
The editions read for this page are Form W-7 (Rev. December 2024) and the Instructions for Form W-7 (Rev. December 2024), which are the revisions irs.gov served when they were read on 2026-10-17. Check the revision printed on the form you are submitting, because a later revision can change the reasons for applying, the documents accepted and the processing statements.
Common mistakes
- Filing Form W-7 while an SSN application is pending. The instructions say “If you have an application for an SSN pending, don’t file Form W-7.”
- Sending the return separately from the application. The instructions say “Don’t file your tax return without Form W-7 and required documentation.”
- Using the return’s mailing address for the package. The instructions say “If you mail your application, don’t use the mailing address in the instructions for your tax return”
Related: Form W-8BEN, Form W-9, Form 1042-S, Form 1040, Form 8938, Form 2555, Form 4868 extension, and non-citizen spouse estate planning.
Sources
- Form W-7 (Rev. December 2024), Application for IRS Individual Taxpayer Identification Number: https://www.irs.gov/pub/irs-pdf/fw7.pdf
- Instructions for Form W-7 (Rev. December 2024): https://www.irs.gov/pub/irs-pdf/iw7.pdf
Read from the IRS documents linked above on October 17, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.