The Canada US tax treaty decides which country taxes a cross-border individual first, caps withholding at 15% on dividends and periodic pensions, and relieves double taxation through foreign tax credits rather than exemptions. Signed September 26, 1980, in force since August 16, 1984, and amended by five protocols (most recently the Fifth Protocol, in force December 15, 2008), the Convention with Respect to Taxes on Income and on Capital sits under every cross-border property, pension, and estate question.[Convention Between the United States and Canada with Respect to Taxes on Income and on Capital (1980), 2026-07]
Read it as an ordering rule plus a credit mechanism. Where real property is involved, the situs country, the one where the property sits, wins every time.
Our call before the detail: the treaty rewards the person who knows three articles cold. Article IV settles residency when both countries claim you. Article XVIII governs RRSPs, 401(k)s, IRAs, and government pensions across the border. Article XXIX-B is the difference between a routine estate and a US estate-tax problem for a Canadian who dies owning Florida property. Everything else is rate mechanics.
The savings clause: what the treaty refuses to fix
Article XXIX(2) is the clause most readers miss. Each country reserves the right to tax its own citizens and residents as if most of the treaty did not exist.[Department of Finance Canada, Consolidated Canada-US Tax Convention (1980, as amended through 2007), 2026-07]
For a US citizen living in Toronto, this is the whole ballgame. The US taxes its citizens on worldwide income wherever they live, and the savings clause preserves that claim; why every US treaty carries one is covered in how tax treaties work. The rate caps do nothing for a US citizen; what survives are the Article XXIX(3) carve-outs: pension deferral, the social security allocation, and double-tax relief. A US citizen in Canada files in both countries for life. Canada taxes on residence, not citizenship, so its mirror is shorter: a Canadian who leaves stops filing on worldwide income but pays the departure tax deemed disposition on the way out.
Article IV: the tie-breaker that decides where you live
Both countries can claim the same person in the same year. Canada treats anyone with sufficient residential ties, or 183 or more days of sojourning, as a resident. The US applies the substantial presence test, a weighted three-year day count that snowbirds cross more often than they expect; both domestic tests are worked through in the tax residency rules guide. When both laws claim you, Article IV(2) breaks the tie in strict order.
The cascade runs: permanent home first (if you have one in only one country, that country wins); then centre of vital interests (where family, employment, and economic life sit); then habitual abode; then citizenship; and if all four fail, the competent authorities settle it by mutual agreement.[Canada-US Tax Convention, Article IV(2) tie-breaker rules, 2026-07]
Two practical notes. A tie-breaker claim is disclosed on Form 8833; a snowbird who merely crossed the substantial presence line usually files Form 8840 for the closer-connection exception instead. And winning the tie-breaker as a US resident makes a Canadian a deemed non-resident, with full departure-tax consequences. This is a residency decision with a price tag, not a filing formality.
Real property: Articles VI and XIII give the situs country first claim
Article VI lets the country where real property sits tax the income from it, and Article XIII does the same for gains on sale. No treaty election moves a Florida rental into Canadian-only taxation or a Toronto condo into US-only taxation.
The treaty does not touch rent. Canada’s 25% Part XIII withholding on gross rents paid to a non-resident stands; the relief is domestic, the section 216 election to file on net rental income at graduated rates.[Income Tax Act, section 216 — alternative re rents and timber royalties, 2026-07] The US mirror is 30% on gross rents paid to a non-resident alien, relieved by the net-rental election under Internal Revenue Code section 871(d) and a Form 1040-NR.
On sale, each country runs a clearance system. A non-resident selling US real property faces FIRPTA withholding, 15% of the gross sale price by default, remitted by the buyer on Form 8288; 10% for homes bought as a residence between US$300,001 and US$1,000,000, 0% at or under US$300,000.[IRS, FIRPTA withholding on dispositions of US real property interests, 2026-07] A non-resident selling Canadian real property needs a section 116 clearance certificate, or the buyer holds back 25% of the price. Both are refundable prepayments, and both are measured on gross proceeds, not gain.
Withholding rates: where the treaty actually cuts
Articles X and XI are where the treaty earns its reputation. Both countries impose statutory withholding on cross-border investment income (25% in Canada, 30% in the US), and the treaty caps those rates by category.
| Payment | Statutory rate | Treaty rate | Article |
|---|---|---|---|
| US dividends to a Canadian resident | 30% | 15% | X |
| Canadian dividends to a US resident | 25% | 15% | X |
| Arm’s-length cross-border interest | 25% / 30% | 0% | XI |
| Rent on Canadian property to a non-resident | 25% of gross | 25% (no treaty relief; s.216 net election) | VI |
| Rent on US property to a non-resident | 30% of gross | 30% (no treaty relief; s.871(d) net election) | VI |
| Periodic pension or RRIF payment from Canada | 25% | 15% | XVIII |
| RRSP lump-sum withdrawal by a US resident | 25% | 25% (lump sums get no cap) | XVIII |
| US Social Security to a Canadian resident | n/a | 0% at source; taxed by Canada only | XVIII(5) |
| CPP/OAS to a US resident | n/a | 0% at source; taxed by the US only | XVIII(5) |
The 5% dividend rate you will see quoted is for corporations owning at least 10% of the payer’s voting stock; portfolio investors get 15%. The zero rate on interest is a Fifth Protocol change: arm’s-length interest went to 0% effective January 1, 2008, and related-party interest phased down through 7% and 4% to 0% by 2010.[US Senate Executive Report 110-15, Protocol Amending the 1980 Tax Convention with Canada, 2026-07]
Claiming the rates is paperwork: Form W-8BEN with US payers, Form NR301 with Canadian ones. A missed form means full statutory withholding, recoverable only by filing in the source country.
Article XVIII: pensions, RRSPs, and the retirement border
Article XVIII does more work for ordinary households than any other article, and the Fifth Protocol rebuilt it around mutual recognition of retirement plans.
RRSPs held by US persons. The US does not treat an RRSP as a qualified plan, so absent the treaty its internal income would be taxable to a US person annually. Article XVIII(7) allows deferral until distribution, automatic since Revenue Procedure 2014-55, which also retired Form 8891.[IRS Revenue Procedure 2014-55, deferral for Canadian registered retirement plans, 2026-07] The deferral covers RRSPs and RRIFs, not TFSAs, which the treaty never mentions; the US taxes TFSA earnings annually; the standing analysis for US persons is in TFSA and RRSP treatment for cross-border owners. Deferral does not switch off US information reporting either: RRSPs still land on the FBAR and Form 8938.
401(k)s and IRAs held by Canadian residents. Canada recognizes US employer plans and IRAs symmetrically: income accrues untaxed and distributions are taxed as pension income. A Canadian resident drawing on a 401(k) faces the treaty’s 15% periodic withholding and reports the income on the T1, crediting the US tax.
Periodic versus lump sum. The 15% cap in Article XVIII(2) applies only to periodic pension payments. A RRIF paying out on a regular schedule qualifies, annual draws no greater than twice the required minimum; a one-shot RRSP collapse by a US resident is a lump sum and takes Canada’s full 25% Part XIII withholding.[CRA, Part XIII non-resident withholding tax rates, 2026-07] The gap between converting to a RRIF and drawing periodically versus cashing out is ten points of withholding.
Government pensions. Article XVIII(5) allocates social security to the residence country alone. A Canadian resident collecting US Social Security pays no US tax on it and includes 85% of it in Canadian income, mirroring the US domestic inclusion cap; a US resident collecting CPP or OAS pays no Canadian tax and reports the benefits in the US as if they were US Social Security.[IRS Publication 597, Information on the United States-Canada Income Tax Treaty, 2026-07] For a retiree choosing a side of the border, this rule outweighs every other article.
Article XXIV: the credit machinery
Article XXIV is where double taxation dies. Each country credits the other’s income tax against its own, subject to its domestic foreign-tax-credit rules: Form 1116 on the US side, the T2209 federal foreign tax credit under section 126 on the Canadian side.
The machinery eliminates double taxation; it does not equalize rates. The combined bill lands at the higher of the two effective rates, and the credit fails at the edges because it is capped at the residence country’s own tax on that income. The classic collisions: a home-sale gain the US shelters only up to its US$250,000 per-person exclusion while Canada’s principal residence exemption is unlimited, and mismatched recognition years, which strand otherwise-valid credits.
Article XXIX-B: the estate tax bridge
The two countries tax death differently: the US levies an estate tax of up to 40% on the fair market value of US-situs assets in a non-resident’s estate; Canada has no estate tax but deems a disposition of capital property at death and taxes the gain. Article XXIX-B, added by the 1995 protocol, is the bridge: it gives a Canadian resident’s estate a pro-rated share of the full US unified credit, adds a marital credit when the US property passes to a surviving spouse, and lets Canada credit US estate tax against the Canadian income tax on the deemed disposition of the same assets.[Canada-US Tax Convention, Article XXIX-B — taxes imposed by reason of death, 2026-07] At the US$15 million per-person exemption in force from 2026, the pro-rated credit protects nearly every Canadian snowbird estate.
None of it is automatic: the credits are claimed on Form 706-NA with a treaty election, and estates that skip the filing forfeit both. The situs rules, the worked pro-ration math, and the filing traps are in the cross-border estate tax guide; structuring around the exposure before death belongs to cross-border estate planning.
Three scenarios the treaty was built for
A Canadian resident with a Florida rental. The US taxes the rental first: 30% of gross rent withheld, or the section 871(d) net election plus an annual 1040-NR, which nearly always wins once depreciation and expenses are counted. Canada taxes the same net income on the T1 and credits the US tax under Article XXIV. The property triggers T1135 reporting once the CAD 100,000 cost threshold is crossed. On sale, FIRPTA withholds 15% of gross proceeds, the real gain settles on a 1040-NR, and Canada computes the same gain in Canadian dollars, so FX movement since purchase is taxable even when the US-dollar price went nowhere. At death, the condo is a US-situs asset inside the Article XXIX-B math above.
A US resident with a Toronto condo. Canada taxes first: 25% of gross rent, or a section 216 net-rate return, with the NR6 undertaking allowing net-basis withholding during the year. The mechanics parallel CRA’s rules for cross-border rental owners. The US taxes the same income on Schedule E with a Form 1116 credit. On sale, the buyer holds back 25% of the price until CRA issues the section 116 clearance certificate, started well before closing because certificates take months. The variant that changes everything is citizenship: under the savings clause a US citizen owner gets no treaty shelter, only credits.
A retiree straddling the border. The first question is Article IV, not Article XVIII: where is the permanent home, and which country wins the tie-breaker? Once residence settles, the pension map follows. A Canadian who retires to Arizona converts the RRSP to a RRIF and draws periodically: Canada withholds 15% instead of 25%, the US taxes the taxable portion of each distribution with the internal growth deferred under Revenue Procedure 2014-55, and the Canadian withholding comes back as a credit. An American who retires to Nova Scotia runs the mirror: 401(k) and IRA draws taxed by Canada as pension income with a 15% US withholding credit. CPP, OAS, and US Social Security each land in the residence country only.
Who the treaty does not help
The treaty does nothing for US state taxes: states are not parties to it, and California is the standing example, taxing the annual RRSP earnings the treaty defers federally. It does not shelter TFSAs, RESPs, or FHSAs held by US persons, does not reduce gross-rent withholding in either direction, and does not file anything for you; an unclaimed benefit is tax paid twice.
Frequently asked questions
Does the treaty stop the US from taxing US citizens living in Canada?
No. The Article XXIX(2) savings clause preserves citizenship-based taxation. The surviving exceptions: pension deferral, the social security allocation, and foreign tax credits.
Is a TFSA protected by the treaty?
No. Article XVIII’s deferral covers RRSPs and RRIFs. The TFSA is invisible to the treaty: the US taxes its earnings annually in the hands of a US person, and its Canadian tax-free status buys nothing across the border.
Do treaty benefits happen automatically?
Mostly no. The RRSP deferral is automatic under Revenue Procedure 2014-55, but reduced withholding requires the right form with the payer (W-8BEN on the US side, NR301 on the Canadian side), and return-level positions such as a tie-breaker residency claim need Form 8833. Information reporting (T1135, FBAR, Form 8938) applies in full.
Which country taxes the gain when I sell my cross-border property?
Both, in sequence. The situs country taxes the gain first under Article XIII; the residence country taxes it too and credits the source tax under Article XXIV. The withholding at closing (FIRPTA 15% in the US, the section 116 holdback in Canada) is a deposit against that tax, not the tax itself.
Where this fits in the library
This page owns the treaty mechanics. Country-by-country consequences live in the taxes hub, and the Canadian-side pages carry the form-level detail: T1135 disclosure for the reporting trigger, foreign rental income rules for the CRA side of a rental, departure tax for anyone whose tie-breaker outcome ends Canadian residency, and cross-border estate planning for structuring around Article XXIX-B rather than just claiming it.