ITIN Explained: Form W-7 for Canadians and Spouses
Who needs one, applying on Form W-7, certified documents, the exceptions, and expiration
Reviewed by the Fairlight Accounting cross-border tax team — U.S. & Canadian Tax Desks
An ITIN — individual taxpayer identification number — is a nine-digit IRS number for people who need a U.S. tax ID but can't get a Social Security number: Canadians filing a U.S. nonresident return, nonresident spouses on joint returns, and dependents. It's requested on Form W-7, usually with the return that needs it.
On this page
Who needs one
| Situation | Why |
|---|---|
| Canadian with U.S. rental income | To file Form 1040-NR with the net-basis election |
| Canadian selling U.S. real estate | To apply for a FIRPTA withholding certificate and file the return (the FIRPTA guide) |
| Nonresident spouse of a U.S. citizen | To file jointly (the nonresident spouse election) or be claimed |
| Canadian claiming a treaty benefit requiring a return | To file Form 1040-NR or Form 8833 |
| Partner in a U.S. partnership | To receive Form 8805 credits |
How to apply
Form W-7 with the federal return that requires the number, plus identity documents — a current passport (original or issuing-agency certified copy) is the only stand-alone document; otherwise two documents, one proving identity and one foreign status, one with a photo. Originals or certified copies (not notarized) can be mailed, or a Certifying Acceptance Agent (in the U.S. or abroad) or an IRS Taxpayer Assistance Center with ITIN services (in the U.S.) can authenticate most documents in person and return them on the spot. The IRS says to allow seven weeks, or nine to eleven weeks during tax season (January 15 to April 30) or for applications from outside the U.S. Five exceptions in the Form W-7 instructions allow applying without a return: passive income with third-party withholding or treaty benefits; other income such as treaty-exempt wages, scholarships, or gambling winnings; mortgage interest reporting; U.S. real estate dispositions subject to FIRPTA withholding (including Form 8288-B withholding certificates); and T.D. 9363 e-filing for foreign corporation representatives.
Expiration
An ITIN not used on a U.S. federal tax return for three consecutive tax years expires on December 31 of the third year and must be renewed on Form W-7 before it goes on a return again. The older middle-digit expiration schedule is complete — any ITIN issued before 2013 that was never renewed has expired. Expired ITINs can still be used on information returns such as Form 1099.
Frequently asked questions
Do Canadians need an ITIN?
Only if they have a U.S. filing requirement or need a U.S. tax ID and aren't eligible for a Social Security number.
Can I apply for an ITIN without a tax return?
Only under specific exceptions, such as a FIRPTA withholding certificate application.
Do I have to mail my passport?
Not if a Certifying Acceptance Agent verifies it.
Does an ITIN expire?
Yes, if not used on a return for three consecutive years.
Official sources
The IRS explains: “An ITIN is a 9-digit number the IRS issues if you need a U.S. taxpayer identification number for federal tax purposes, but you aren’t eligible for a Social Security number (SSN).” — Internal Revenue Service, Individual taxpayer identification number (ITIN), https://www.irs.gov/tin/itin/individual-taxpayer-identification-number-itin
Next step
Fairlight Accounting is a cross-border accounting and tax practice with a U.S. Tax Desk and a Canadian Tax Desk. Our U.S. Tax Desk and Canadian Tax Desk handle ITIN applications through Form W-7, Certifying Acceptance Agent document review, and the U.S. returns that require them. See pricing or book a call.
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U.S. and Canadian filings prepared together by our U.S. and Canadian Tax Desks.
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