The US-Canada Tax Treaty: What Each Article Does and When It Applies

The Convention Between Canada and the United States of America With Respect to Taxes on Income and on Capital was signed September 26, 1980, entered into force August 16, 1984, and has been updated by five protocols (1983, 1984, 1995, 1997, and the Fifth Protocol signed September 21, 2007). It is the framework that determines which country taxes each type of cross-border income, at what rate, and how the other country provides relief. Without it, a US citizen living in Canada would owe full tax in both countries on the same income. With it, the treaty allocates primary taxing rights, reduces withholding rates, and ensures a foreign tax credit mechanism that prevents double taxation.

How does the treaty decide which country taxes what?

The treaty assigns primary taxing rights by income type. For each category, one of three structures applies: exclusive taxation by the residence country (the source country cannot tax the income at all), shared taxation with a capped withholding rate (the source country can tax but only up to a specified rate, and the residence country gives a credit), or full source-country taxation (the source country taxes at its domestic rates, and the residence country gives a credit).

“Residence” for treaty purposes is determined under Article IV. A person is a resident of the country where they are liable to tax by reason of domicile, residence, citizenship, place of management, or a similar criterion. When a person qualifies as a resident of both countries (common for US citizens living in Canada, since the US taxes citizens regardless of residence), the treaty’s tie-breaker rules in Article IV(2) determine residence for treaty purposes: permanent home, centre of vital interests, habitual abode, citizenship, and if all else fails, mutual agreement between the competent authorities.

The saving clause in Article XXIX(2) is the treaty’s most important structural feature for US citizens. It says that, with certain exceptions, nothing in the treaty prevents the US from taxing its citizens and residents as if the treaty did not exist. This means the US still taxes its citizens on worldwide income even when the treaty assigns primary taxing rights to Canada. The treaty’s benefit for US citizens comes through the foreign tax credit (Article XXIV) and through the specific articles that override the saving clause (pensions, Social Security, alimony, child support).

What are the withholding rates on dividends, interest, and royalties?

Dividends (Article X). The source country can withhold up to 15% on dividends paid to a resident of the other country. If the beneficial owner is a company that owns at least 10% of the voting stock of the paying company, the rate drops to 5%. These are the maximum treaty rates; domestic law may set a lower rate. Canada’s domestic rate on dividends paid to non-residents is 25% (under ITA 212(2)), so the treaty reduces it to 15% (or 5% for qualifying corporate shareholders). The US domestic rate on dividends paid to non-resident aliens is 30% under IRC 1441, reduced to 15% (or 5%) by the treaty.

Interest (Article XI). The Fifth Protocol (2008) reduced the treaty withholding rate on interest to 0% for most categories. Interest paid by a resident of one country to a resident of the other is generally exempt from source-country withholding. Exceptions apply to certain contingent-interest arrangements and to interest that is an excess inclusion from a real estate mortgage investment conduit. Before the Fifth Protocol, the rate was 10%.

Royalties (Article XII). Copyright royalties and similar payments for literary, dramatic, musical, or artistic works (excluding film/TV royalties) are subject to a maximum 10% withholding. All other royalties, including payments for the use of patents, trademarks, designs, models, plans, know-how, and computer software, are taxable only in the residence country (0% withholding). This distinction matters for cross-border licensing arrangements: a Canadian company paying a US licensor for software rights owes no withholding under the treaty, but a Canadian publisher paying a US author owes up to 10%.

How does the treaty handle pensions and retirement accounts?

Article XVIII is the most heavily used treaty provision for cross-border individuals. It covers pensions, annuities, Social Security, and retirement savings accounts (RRSPs, RRIFs, IRAs, 401(k)s).

Periodic pension payments (Article XVIII(1)-(2)). Pensions and annuities arising in one country and paid to a resident of the other may be taxed in both countries, but the source-country withholding is capped at 15% for periodic payments. A lump-sum distribution from a pension may be taxed in the source country at its domestic rates (no 15% cap), which is why the lump sum vs periodic decision matters for RRSP withdrawals after moving to the US.

Social Security (Article XVIII(5)). Benefits paid by one country to a resident of the other are taxable only in the residence country. A US citizen living in Canada who receives US Social Security reports it on the Canadian return only. The US does not tax it (the saving clause is overridden for this specific provision). For Canadian residents, only 85% of the benefit is included in income. See the Social Security in Canada guide for the mechanics.

Retirement account deferral (Article XVIII(7)). A resident of one country who is a beneficiary of a pension, retirement, or employee benefits plan in the other country may elect to defer taxation on income accrued in the plan but not yet distributed. This is the provision that allows a US citizen living in Canada to elect that RRSP growth is not taxed currently in the US (matching the Canadian deferral), and a Canadian living in the US to elect deferral on a 401(k) or IRA. The election is made on the US return and requires Form 8891 (now automatic for eligible individuals under Revenue Procedure 2014-55, but the election right derives from Article XVIII(7)).

When is employment income taxed in the other country?

Article XV allocates employment income to the country where the services are performed, not where the employer is located or where the employee resides. If a Canadian resident crosses the border to perform services in the US, the US has the right to tax the income attributable to those days.

There is a short-stay exception: employment income is taxable only in the residence country if (1) the employee is present in the other country for no more than 183 days in any 12-month period, (2) the remuneration is paid by or on behalf of an employer who is not a resident of the other country, and (3) the remuneration is not borne by a permanent establishment or fixed base in the other country. All three conditions must be met. The 183-day count runs on a 12-month period, not a calendar year.

For the Windsor-Detroit commuter or a Canadian employee sent on a US assignment, Article XV means the US taxes the income for days worked in the US, Canada taxes the worldwide income (including the US days), and the foreign tax credit under Article XXIV eliminates the double count.

How are capital gains and real property treated?

Article XIII allocates capital gains on real property to the country where the property is located (the situs country). If a Canadian resident sells US real property, the US taxes the gain and Canada gives a credit. If a US resident sells Canadian real property, Canada taxes the gain (with the section 116 holdback mechanism) and the US gives a credit.

Gains on other property (shares, bonds, personal property) are generally taxable only in the residence country, with some exceptions. Gains on shares of a company whose value derives principally from real property in one country may be taxed in that country. Gains on business property of a permanent establishment may be taxed in the country where the PE is located.

Article XIII(7) addresses the situation where a person was a resident of one country and becomes a resident of the other. It allows the person to elect to be treated as having sold and reacquired property at fair market value at the time of the change of residence, for purposes of taxation in the former country of residence. This is the election that interacts with Canada’s departure tax: Canada deems a disposition on departure, and the US can step up basis to match under Article XIII(7).

How does the treaty prevent double taxation?

Article XXIV is the mechanical article that makes the treaty work. It requires each country to allow a credit for the tax paid to the other country on the same income, subject to the limitations of its domestic law.

For the US, the credit mechanism is Form 1116 (the foreign tax credit), which allows a US person to credit Canadian tax against US tax on the same income, subject to the IRC 904 limitation (the credit cannot exceed the US tax attributable to the foreign-source income). For Canada, the mechanism is ITA 126, which allows a credit for US tax paid on income that is also taxable in Canada.

The practical result: the taxpayer pays the higher of the two countries’ tax rates on each category of income, not both. If Canadian tax on employment income is 35% and US tax on the same income is 24%, the Canadian tax satisfies the US liability in full (with excess credits that may carry forward). If US tax on a capital gain is higher than the Canadian tax, the Canadian credit does not fully offset, and the US collects the difference.

For US citizens living in Canada, the saving clause means the US taxes their worldwide income as if they were a US domestic filer, and the FTC under Article XXIV credits the Canadian tax they paid. Because Canadian marginal rates on employment income typically exceed US rates, the FTC usually eliminates the US tax entirely on earned income. The gap appears on types of income where the US rate exceeds the Canadian rate: capital gains (US taxes at up to 23.8% while Canada’s rate depends on the inclusion rate and province), and certain types of investment income.

What should I do next?

The treaty applies automatically to items like withholding rates (the payer applies the treaty rate when a valid form is on file), but some provisions require an affirmative election or disclosure. The Form 8833 treaty-based return position disclosure is required whenever you take a position on your US return that the treaty reduces or modifies your US tax. The RRSP deferral election under Article XVIII(7) is now automatic for eligible individuals, but non-standard pension arrangements may still require an explicit election.

• Does Canada have a tax treaty with the US?, the short overview for people who just need to know if a treaty exists
• When do I need Form 8833?, the treaty disclosure requirement
• Getting the 15% treaty rate on IRA/401(k) withdrawals, Article XVIII applied to retirement withdrawals
• US Social Security taxed in Canada, Article XVIII(5) in practice
• FEIE or foreign tax credit?, Article XXIV’s credit mechanism vs the exclusion

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