I filed the wrong departure year, or never filed one at all. Can I still fix it?

Usually yes, and the repair runs on two clocks that close at different times. In Canada, ITA 152(4.2) lets an individual (other than a trust) or a graduated rate estate apply within 10 calendar years after the end of that taxation year, for a refund or a reduction of an amount payable, and the Minister may reassess rather than must. In the US, IRC 6511(a) gives 3 years from the date you filed or 2 years from the date you paid, whichever is later, and IRC 6511(d)(3)(A) substitutes 10 years only where the overpayment is attributable to foreign tax.

Which year does my departure actually belong in?

The year that holds the date your residence ceased, and nothing else moves it. ITA 128.1(4) opens “where at a particular time a taxpayer ceases to be resident in Canada”, and paragraph (b) hangs the deemed disposition on that same particular time (ITA 128.1). The T1161 list in ITA 128.1(9) keys to the same cessation. So a contract start date, a flight, or the day the bank changed your address doesn’t move the year unless that’s the day the ties broke.

“For the purposes of this Act, where at a particular time a taxpayer ceases to be resident in Canada,” and then, at paragraph (b), “the taxpayer is deemed to have disposed, at the time (in this paragraph and paragraph (d) referred to as the “time of disposition”) that is immediately before the time that is immediately before the particular time, of each property owned by the taxpayer other than, if the taxpayer is an individual,” (ITA 128.1(4)).

Working out which day that was is a different question from repairing the return, and it’s covered in whether you actually stopped being a Canadian tax resident. Filing an NR73 to get the CRA’s written determination is one way to pin that date. This page takes the date as given.

I kept filing as a Canadian resident after I left. How do I fix those years?

One year at a time, and the CRA’s two online channels answer differently for the same return. The CRA lists a return for someone who left Canada during the year among the returns its ReFILE service is unable to change. Change my return reaches it: the same CRA page’s own tool, asked about an emigrant return for 2016 to 2025, answers that “your only online option is the “Change my return” service” (CRA, Changing a tax return). On paper it’s Form T1-ADJ, one request per year.

The exclusion, in the CRA’s words, sits in the list of what “you cannot use “ReFILE” to change”: “A return for an international or non-resident taxpayer, including deemed residents of Canada and individuals who left Canada during the year”. The eligibility sits one disclosure lower on the same page: “You can use “Change my return” to change certain international and non-resident returns, such as:”, and the list that opens names “Emigrant returns” (CRA, Changing a tax return).

Both statements are on one page and both are true, so the online route can look shut when it isn’t. The paper route still matters for older years: for a return for the 2015 tax year or earlier the CRA says there are no online options, and “a refund cannot be issued for an adjustment request made more than 10 calendar years after the end of the tax year”. Either way, “Send any request to change a previous return separately from your current year tax return.” The CRA quotes 2 weeks for the online channels and 12 weeks by mail.

How far back can I go on each side?

Ten calendar years in Canada, three or two in the US, each measured from a different event. ITA 152(4.2) lets an individual (other than a trust) or a graduated rate estate apply within 10 calendar years after the end of that taxation year, for a refund or a reduction, and the Minister may rather than must (ITA 152). IRC 6511(a) runs 3 years from filing or 2 from payment, whichever is later (IRC 6511). Where the overpayment is attributable to foreign tax, IRC 6511(d)(3)(A) substitutes 10 years from the due date of the return for the year those taxes were paid.

The repair you’re asking for	The window	Measured from	The condition on that answer
Canada, asking for a refund or a lower amount payable	10 calendar years	The end of that taxation year	ITA 152(4.2), and every limb of it matters: the applicant is an individual (other than a trust) or a graduated rate estate, the purpose is “the amount of any refund to which the taxpayer is entitled … or a reduction of an amount payable”, and the Minister “may” reassess on the application rather than must
Canada, where the correct year makes you owe more	Not this provision	n/a	ITA 152(4.2) reaches only a refund or a reduction of an amount payable, so a fix running the other way sits outside it. ITA 152(4) is the provision that sets when the CRA may assess or reassess after the normal reassessment period, and this page doesn’t run its conditions
US refund claim with no foreign tax in it	The later of 3 years and 2 years	The date the return was filed, and the date the tax was paid	IRC 6511(a), whichever of the two periods expires later. Its own third limb: “if no return was filed by the taxpayer, within 2 years from the time the tax was paid”. IRC 6511(b)(2)(B) caps the amount separately, and it limits what the claim recovers rather than adding a period: a claim filed outside the 3-year period recovers no more than the tax paid in the 2 years before the claim. IRC 6511(d)(3)(B) lifts that cap for a foreign-tax claim, which is the row below, and the other IRC 6511(d) lifts are not run on this page
US refund claim attributable to foreign tax	10 years	The date prescribed by law for filing the return for the year those foreign taxes were actually paid or accrued, which is not the year being amended	IRC 6511(d)(3)(A), and only where the overpayment is attributable to taxes paid or accrued to a foreign country for which credit is allowed under IRC 901 or a treaty. IRC 6511(d)(3)(B) then lifts the subsection (b) cap on the amount, to the extent of the overpayment attributable to that credit
The T1161 that never went in	Its own penalty rather than a window	The filing-due date for the year residence ceased	ITA 128.1(9) sets the obligation and ITA 162(7) prices it, at the greater of $100 and $25 multiplied by the days the failure continues, capped at 100 days, “except where another provision of this Act … sets out a penalty for the failure”

• The IRS states the same US rule in its own words and then qualifies it two sentences later: “To claim a refund, you must file Form 1040-X within 3 years after the date you filed your original return or within 2 years after the date you paid the tax, whichever is later”, and “Special rules apply for refund claims relating to net operating losses, foreign tax credits, bad debts, and other issues” (IRS, Topic no. 308). The foreign tax credit one is IRC 6511(d)(3)(A).
• A 152(4.2) application has conditions of its own, and they sit with taxpayer relief and the ten-year application clock, which is the page that already carries that subsection.

I never filed the departure return at all. What happens now?

You still file it, and the list is a separate exposure from the tax. ITA 128.1(9) makes an individual who ceased to be resident, holding reportable property worth more than $25,000, file the T1161 by the filing-due date for that year, and that year is the year the ties broke rather than the year you filed (ITA 128.1). ITA 162(7) prices a missed information return at the greater of $100 and $25 a day, capped at 100 days, except where another provision of the Act already sets out a penalty for that same failure (ITA 162).

“Every person (other than a registered charity) or partnership who fails (a) to file an information return as and when required by this Act or the regulations, or (b) to comply with a duty or obligation imposed by this Act or the regulations is liable in respect of each such failure, except where another provision of this Act (other than subsection 162(10) or 162(10.1) or 163(2.22)) sets out a penalty for the failure, to a penalty equal to the greater of $100 and the product obtained when $25 is multiplied by the number of days, not exceeding 100, during which the failure continues.” (ITA 162(7))

The carve-out is the part worth reading twice: where another provision of the Act already sets a penalty for that same failure, 162(7) steps aside. The forms themselves, and what the departure year should have looked like, are on the departure-year forms page. Before filing cold, the Voluntary Disclosures Program is worth weighing, and its conditions live on that page rather than this one.

One thing this page deliberately doesn’t answer. ITA 152(3.1)(b) starts the normal reassessment period running “three years after the earlier of the day of sending of a notice of an original assessment … and the day of sending of an original notification that no tax is payable”. What that means for a year where nothing was filed and nothing was ever assessed isn’t worked out here, and you shouldn’t read the silence either way.

Which side do I fix first?

Compute both dates, because the shorter window isn’t always the one you’d guess. IRC 6511(a) measures from the date you filed or the date you paid, so a US return filed four years ago can already be out of time while the Canadian year is still open (IRC 6511). ITA 152(4.2) measures from the end of the taxation year, so its 10 years runs on a fixed calendar (ITA 152). And where the overpayment is attributable to foreign tax, IRC 6511(d)(3)(A) measures its 10 years from the due date of the return for the year those taxes were actually paid or accrued, which is a different event again.

“If the claim for credit or refund relates to an overpayment attributable to any taxes paid or accrued to any foreign country or to any possession of the United States for which credit is allowed against the tax imposed by subtitle A in accordance with the provisions of section 901 or the provisions of any treaty to which the United States is a party, in lieu of the 3-year period of limitation prescribed in subsection (a), the period shall be 10 years from the date prescribed by law for filing the return for the year in which such taxes were actually paid or accrued.” (IRC 6511(d)(3)(A))

What should I do next?

Fix the date first, because every other answer hangs off it. Write down the day the ties actually broke and which year holds it, since ITA 128.1(4) keys the deemed disposition and ITA 128.1(9) keys the T1161 to that same day. Then compute two dates: 10 calendar years after the end of that taxation year, which is the outside of an ITA 152(4.2) application in the refund direction, and the later of 3 years from filing and 2 years from payment under IRC 6511(a), which stretches to 10 years where the overpayment is attributable to foreign tax.

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.