Resident of Both Countries? How the Treaty Tie-Breaker Decides, and What Happens After It Does

Short version: Form 8833: Disclosing a Treaty-Based Return Position

It is possible to be a tax resident of both countries at once: a Canadian resident under the residential-ties test who also meets the US substantial presence test, or a green card holder living in Canada, or someone in the months around a move whose ties have not fully shifted. Article IV(2) of the treaty resolves dual residency with a sequence of tests, and the answer determines which country taxes worldwide income and which taxes only source income. The tie-breaker is not optional in the sense that the result follows from the facts, but claiming it requires filing in both countries and produces consequences that are not always welcome.

Key takeaways

• The tests, in order: permanent home available in only one country; if in both or neither, centre of vital interests (closer personal and economic relations); if indeterminate, habitual abode; if in both or neither, citizenship; if both or neither, competent authority agreement.
• Winning the tie-breaker for Canada makes you a deemed non-resident of Canada under section 250(5)? No: winning it for Canada keeps you a Canadian resident and makes you a US non-resident, filing a 1040-NR with Form 8833. Winning it for the US makes you a deemed non-resident of Canada under section 250(5), with the departure tax and non-resident consequences.
• Green card holders who claim treaty residence in Canada file a 1040-NR with Form 8833; doing so can be treated by immigration authorities as abandonment of the green card and, for long-term residents, can trigger the expatriation rules.
• Dual residency is usually a departure-year problem and resolves once the ties have shifted; the tie-breaker settles the months in between.

The tests

Permanent home. A dwelling available for your continuous use, owned or rented, not a hotel or a temporary stay. A Canadian who has sold the Toronto house and bought in Florida has a permanent home only in the US. One who kept the Toronto house (even rented out on a short lease that leaves it available) and bought in Florida has one in both.

Centre of vital interests. Where your personal and economic relations are closer: family, social relations, occupation, political and cultural activities, place of business, place from which property is administered. The CRA and IRS weigh these together. A person whose spouse and children are in Canada and whose employer is in the US often has a Canadian centre of vital interests; one whose family has moved and whose remaining Canadian ties are an RRSP and a bank account has a US one.

Habitual abode. Where you spend more time, measured over a period long enough to be meaningful. If you have a permanent home in both countries and the vital interests test is inconclusive, the country where you are more regularly present wins.

Citizenship. A Canadian citizen who is not a US citizen is assigned to Canada; a US citizen who is not Canadian, to the US. Dual citizens go to competent authority.

Competent authority. The two tax agencies agree on a resolution through the mutual agreement procedure.

What happens when the tie breaks

Assigned to Canada. For Canadian purposes you remain a resident, taxed on worldwide income. For US purposes you are a non-resident alien for the period: you file a 1040-NR reporting US-source income, attach Form 8833 disclosing the treaty position, and are exempt from the resident-alien reporting regime (FBAR still applies if you are a US citizen or green card holder, and Form 8938 has its own rules). US-source wages remain taxable in the US under Article XV unless exempt.

Assigned to the US. For US purposes you are a resident, taxed on worldwide income. For Canadian purposes, section 250(5) deems you a non-resident from the date the treaty assigns you to the US, which triggers the departure tax (deemed disposition), ends Canadian taxation of worldwide income, and starts Part XIII withholding on Canadian-source income. This is the mechanism by which a Canadian who has not formally 'left' can be pushed out by the treaty.

The green card holder in Canada

A US permanent resident living in Canada is a US resident under US law (the green card test) and a Canadian resident under Canadian law. The tie-breaker usually assigns them to Canada (permanent home and vital interests in Canada). Claiming that position requires a 1040-NR with Form 8833, and it carries two risks: US immigration authorities may treat a treaty non-resident claim as evidence of abandoning permanent residence, and for a green card holder who has held the card in eight of the last fifteen years, claiming treaty non-residence is treated as expatriation, triggering the exit tax rules if the person is a covered expatriate. Green card holders in Canada should decide deliberately between filing as a US resident (with the FEIE or foreign tax credit) and claiming the treaty position.

The departure year

Most dual-residency questions arise in the year of a move, when a person has left one country in fact but not yet severed every tie. The tie-breaker settles the period between the physical move and the point at which the old country's ties are gone. A Calgary engineer who starts in Houston on June 1 while the family stays until August 20 is a Canadian resident until August 20 by the CRA's own departure-date rule, and if the US also claims him from June 1 under the substantial presence test, the tie-breaker (permanent home in Canada, family in Canada) keeps him Canadian until the family leaves. The US taxes his Houston wages under Article XV for that window as a non-resident.

Worked example

A Toronto executive takes a New York job on March 1, rents a Manhattan apartment, and keeps the Toronto house where her husband and children remain until the school year ends on June 25.

• March 1 to June 25. Permanent home in both (Toronto house available; Manhattan apartment). Centre of vital interests: family, social relations, and property in Toronto; employment in New York. Weighed together, Canada. Tie-breaker assigns her to Canada. Canada taxes worldwide income (with a foreign tax credit for New York tax on the wages); the US taxes the New York wages on a 1040-NR with Form 8833.
• June 25 onward. Family in New York; Toronto house listed for sale. Permanent home in the US only once the house is sold or leased out; vital interests in the US. Tie-breaker assigns her to the US; section 250(5) deems her a non-resident of Canada from that date; departure tax applies; the final T1 shows a June 25 departure date.

Official sources

"Where by reason of the provisions of paragraph 1 an individual is a resident of both Contracting States, then his status shall be determined as follows: (a) he shall be deemed to be a resident of the Contracting State in which he has a permanent home available to him; if he has a permanent home available to him in both States or in neither State, he shall be deemed to be a resident of the Contracting State with which his personal and economic relations are closer (centre of vital interests); (b) if the Contracting State in which he has his centre of vital interests cannot be determined, he shall be deemed to be a resident of the Contracting State in which he has an habitual abode; (c) if he has an habitual abode in both States or in neither State, he shall be deemed to be a resident of the Contracting State of which he is a citizen; and (d) if he is a citizen of both States or of neither of them, the competent authorities of the Contracting States shall settle the question by mutual agreement." — Canada-United States Tax Convention, Article IV(2), https://www.canada.ca/en/department-finance/programs/tax-policy/tax-treaties/country/united-states-america-convention-consolidated-1980-1983-1984-1995-1997.html

"Taxpayers use this form to make the treaty-based return position disclosure required by Internal Revenue Code section 6114. Dual-resident taxpayers use this form to make the treaty-based return position disclosure required by Regulations section 301.7701(b)-7." — Internal Revenue Service, About Form 8833, https://www.irs.gov/forms-pubs/about-form-8833

Practitioner note

The tie-breaker is a set of facts, not a choice, but the facts can be arranged: sell or lease the house, move the family, close the accounts. Clients who want a clean departure date arrange the facts to produce one; clients who want to remain Canadian while working in the US keep the permanent home and the family in Canada and file the 1040-NR with Form 8833. Either works. Drifting between them for a year does not.

See also: For each tie-breaker test worked through with the evidence the CRA and IRS look for, read the treaty tie-breaker, test by test. Planning a move? Start with the Canada-to-US tax checklist and browse every corridor by city, province, and state.

Next step

Fairlight prepares the dual residency analysis under Article IV, the Form 8833 filing where the treaty position is claimed, and the departure or non-resident returns that follow. See cross-border pricing or book a call.