Sell a property abroad and two countries tax the same gain. Nearly every income tax treaty gives the country where the property sits the first claim; the seller’s home country then taxes the identical gain and credits the foreign tax, so the total bill lands near the higher of the two rates, not the sum. The credit does not fix three gaps: gains that exist only in the home currency, a principal-residence exemption one country grants and the other caps, and withholding that takes 2.5 to 25 percent of the gross price at closing. That is where sellers lose real money.
Why the property’s country taxes the sale first
Article XIII of the Canada-United States tax convention states the rule in one sentence: gains a resident of one country derives from selling real property situated in the other country “may be taxed” in that other country.[Convention Between Canada and the United States of America With Respect to Taxes on Income and on Capital, Article XIII, 2026-07] Article 13(1) of the OECD Model Convention carries the same allocation into the treaties with Mexico, Spain, Portugal, and Italy. Tax practitioners call it the situs rule: land is taxed where it sits.
“May be taxed” is non-exclusive. The situs country gets the first claim, but the residence country keeps its right to tax the same gain and must credit the situs country’s tax under the treaty’s relief article. The treaty decides the order, not whether the home country taxes at all. A Canadian resident selling in Spain pays Spanish tax first, reports the same gain on the Canadian return, and claims the Spanish tax as a foreign tax credit; an American selling in Mexico runs the identical sequence with the SAT and the IRS.
Coverage is not universal. The US has income tax treaties in force with Mexico, Spain, Portugal, and Italy, and none with Costa Rica, Panama, Belize, or the Dominican Republic.[IRS, United States income tax treaties A to Z, 2026-07] Canada’s network is one country wider: full conventions with those four plus the Dominican Republic, only tax information exchange agreements with Costa Rica and Panama, and nothing with Belize.[Department of Finance Canada, Tax treaties, 2026-07]
Selling in a country with no treaty
No treaty does not mean double taxation. Both countries tax exactly as they would have anyway; relief shifts from the treaty article to domestic law. The US allows a unilateral foreign tax credit under its own code, and Canada does the same through section 126 of the Income Tax Act. What a no-treaty seller loses is the secondary machinery: residency tie-breakers, capped withholding on rental income during the holding period, and a mutual agreement procedure when the two tax authorities disagree. The credit itself runs the same either way; the market-by-market accounting of the gap is in countries with no tax treaty.
The home-country bill on the same gain
A US person, meaning a citizen or green card holder wherever they live, owes US tax on worldwide capital gains, foreign real estate included. The gain is computed in US dollars, qualifies for long-term capital gains rates after a one-year holding period, and the foreign tax is claimed on Form 1116 in the passive income category. Because a gain on real property abroad is foreign-source income, the credit can absorb the foreign tax, and excess credit carries back one year and forward ten.[IRS, Publication 514, Foreign Tax Credit for Individuals, 2026-07]
A Canadian resident owes Canadian tax on worldwide gains too, with one structural difference: only one-half of a capital gain is included in income and taxed at marginal rates. The proposed increase to a two-thirds inclusion rate was cancelled in March 2025, so 50 percent remains the enacted rate.[Prime Minister of Canada, news release cancelling the proposed capital gains inclusion rate increase, March 21, 2025, 2026-07] The foreign tax comes back as a credit under section 126, computed country by country, and the non-business credit is a same-year calculation with no carryforward: a Canadian whose foreign tax exceeds the Canadian tax on the same gain cannot bank the difference.[CRA, Income Tax Folio S5-F2-C1, Foreign Tax Credit, 2026-07]
One trap sits inside the credit itself: the creditable amount is the final foreign tax liability, not the amount withheld at closing. Spain holds back 3 percent of the price, but the credit follows the number on the seller’s final Spanish return. Claiming the gross withholding when part of it comes back as a refund is one of the most common cross-border filing errors on property sales. The full credit mechanics live in the Form 1116 foreign tax credit guide for American sellers and the Canadian foreign tax credit page for Canadian ones.
Two Canadian housekeeping items travel with the sale. A foreign income property still belongs on the T1135 in the year of disposition, gain or loss included. And ceasing Canadian residency triggers a deemed disposition of most foreign property at fair market value, covered in the departure tax guide.
The FX trap: the gain is measured in your home currency
Neither the IRS nor the CRA taxes the gain in euros or pesos. The US requires each leg translated into dollars at the spot rate on its own date: purchase price at the acquisition-date rate, sale proceeds at the disposition-date rate.[IRS, Foreign currency and currency exchange rates, 2026-07] Canada requires the same two-date computation in Canadian dollars under section 261 of the Income Tax Act.[Income Tax Act, section 261, Canadian currency requirement, 2026-07]
A property that sold for exactly what it cost in local currency can still produce a taxable gain at home, because the currency moved between the two dates. The rates below are illustrative; the arithmetic is the real rule:
| Local currency | Canadian dollars | |
|---|---|---|
| Purchase, EUR/CAD at 1.45 | €300,000 EUR | $435,000 CAD |
| Sale seven years later, EUR/CAD at 1.55 | €300,000 EUR | $465,000 CAD |
| Taxable gain | zero | $30,000 CAD |
The euro position went nowhere; the Canadian return shows a $30,000 CAD capital gain. The mechanism runs in reverse too: a local-currency profit shrinks, or becomes a loss, when the home currency strengthened over the holding period.
The FX component is the worst-taxed slice of the whole transaction, because the situs country never sees it. Spain taxes the euro gain, which in the table above is zero, so no Spanish tax exists to credit against the Canadian bill. The currency slice arrives at home with no credit to shelter it. Sellers who model after-tax proceeds in local currency alone underestimate the home-country bill.
US sellers who carried a mortgage in the local currency face a second FX calculation: paying off a foreign-currency loan when the dollar has strengthened produces an exchange gain under section 988 of the Internal Revenue Code, taxed as ordinary income, while the mirror-image personal exchange loss is generally not deductible.[Internal Revenue Code, 26 U.S.C. section 988, Treatment of certain foreign currency transactions, 2026-07] The property gain and the mortgage FX result are computed independently and can point in opposite directions on the same closing.
The principal-residence mismatch
If the foreign property was a home rather than a rental, the two countries relieve the gain with tools that do not line up.
The US tool is the section 121 exclusion: up to $250,000 USD of gain excluded for a single filer, $500,000 USD for a married couple filing jointly, if the seller owned and used the home as a main home for at least two of the five years before the sale. It applies to a home anywhere in the world, but gain above the cap is taxed.[IRS, Publication 523, Selling Your Home, 2026-07]
The Canadian tool is the principal residence exemption: no dollar cap at all, but only one property per family unit can be designated for each tax year, and a foreign home qualifies only if the family ordinarily inhabited it.[CRA, Income Tax Folio S1-F3-C2, Principal Residence, 2026-07] Designating the villa in Portugal for six years strips those six years from the Toronto house. The designation math, and when it favours the foreign property, is worked through in the principal residence exemption guide.
The mismatch bites hardest on dual-exposure sellers. A US citizen living in Canada sells the family home in Vancouver: Canada exempts the entire gain under the PRE, but the US, which taxes its citizens wherever they live, caps the exclusion at $250,000 USD or $500,000 USD. Gain above the cap is US-taxable, and because Canada collected nothing, there is no Canadian tax to credit against it. The seller’s own principal residence generates a five-figure US bill precisely because the Canadian exemption worked. The reverse pattern hits a Canadian designating a foreign vacation home: the PRE only shelters the Canadian side, and the situs country taxes the sale under its own rules.
Withholding at closing: what the situs country holds back
Most property-country tax systems do not trust a departing foreign seller to file, so they collect at closing, from the gross price, through the buyer or the notary. The withholding is an advance on the real tax, and the spread between the two is the seller’s cash-flow problem until the local return is filed.
| Where the property sits | Withheld at closing | Against a final tax of | Reclaim path |
|---|---|---|---|
| United States (FIRPTA) | 15% of the gross amount realized, held by the buyer | Actual US tax on the gain | Reduced-withholding certificate before closing, or refund with the US return[IRS, FIRPTA withholding of tax on dispositions of United States real property interests, 2026-07] |
| Canada (section 116) | 25% of the gross price unless the seller obtains a clearance certificate | Canadian tax on the gain | T2062 clearance certificate computed on the gain, then a Canadian return[Income Tax Act, section 116, Disposition by non-resident person of certain property, 2026-07] |
| Spain | 3% of the price, remitted by the buyer on Modelo 211 | Non-resident tax on the actual gain | Seller files Modelo 210 within four months; excess refunded[Agencia Tributaria, Non-residents: taxation on real estate transfers, 2026-07] |
| Mexico | ISR calculated and remitted by the notario | Non-resident election: 25% of gross proceeds, or 35% of the net gain with a Mexican tax representative | Election is made at closing; the 35%-of-net route requires documented cost basis[PwC Worldwide Tax Summaries, Mexico: individual income determination, 2026-07] |
| Panama | 3% of the higher of sale price or cadastral value | 10% of the actual gain | Advance credited; refund claim if 10% of the gain is lower[PwC Worldwide Tax Summaries, Panama: other taxes, 2026-07] |
| Costa Rica | 2.5% of the price when the seller is non-domiciled, withheld by the buyer | 15% of the gain under the standard regime | Withholding settles or credits against the gain computation[PwC Worldwide Tax Summaries, Costa Rica: income determination, 2026-07] |
The gross-price regimes, FIRPTA’s 15 percent and Canada’s 25 percent, can hold back several multiples of the actual tax on a low-gain sale, so the certificate procedures that let the withholding be computed on the gain are worth starting well before closing. And the home-country credit waits for the final situs-country number, so a seller whose refund takes a year is financing both tax systems in the interim.
Rates, notary practice, cost-basis documentation, and reclaim timelines for each market live in the country tax pages, for example Mexico for Canadian buyers for the Mexican ISR election and Spain for American buyers for the Spanish non-resident regime.
FAQ
Is the foreign tax on the sale credited dollar for dollar at home?
Only up to the home-country tax on that same income. The US limits the credit by category on Form 1116; Canada limits it per country under section 126. Foreign tax above the limit carries forward on the US side and is lost on the Canadian non-business side.
The property country already taxed the sale. Does the home country really tax it again?
Yes. Both the US and Canada tax residents on worldwide gains, and the US taxes its citizens even when they live abroad. The situs country taxes first and the home country credits, so the combined bill approximates the higher rate rather than doubling, but a home-country return reporting the sale is not optional.
Can a sale with no local-currency profit still be taxed?
Yes, and it is common. The gain is measured in the home currency using the exchange rates on the purchase and sale dates, so currency movement alone can create the entire taxable gain. No foreign tax exists on that slice, so the credit gives no protection.
Does the US home-sale exclusion work on a house overseas?
Yes. Section 121 applies to a main home anywhere in the world, with the same two-of-five-year ownership and use tests and the same $250,000 USD and $500,000 USD caps. It does nothing on the situs-country side, which taxes under its own rules.
Where to go next
The taxes and treaties hub holds the full library, including how the foreign tax credit works on the US side and the general double-taxation framework. Canadian sellers should read the principal residence exemption analysis before designating anything, confirm the T1135 reporting treatment in the year of sale, and check the departure tax rules if a change of residency is in the plan. The per-country tax pages, such as Mexico for Canadian owners and Spain for American owners, carry the closing-table specifics for where the property sits.
Disclaimer
This article is for informational purposes only and does not constitute tax advice. Tax laws change frequently and individual circumstances vary. Consult a qualified cross-border tax advisor before making decisions based on this information. CrossingHQ does not provide tax preparation, advice, or representation services.
Current as of 2026-07-23. We review tax content quarterly and update on rule changes. To report an error, contact us.