Canadian Principal Residence Exemption Under Section 40(2)(b)

The principal residence exemption in Canada shelters the capital gain from selling a home you owned and ordinarily lived in, and when it covers every year of ownership it eliminates the taxable gain entirely. The rule sits in Section 40(2)(b) of the Income Tax Act, and because capital gains otherwise carry a 50% inclusion rate, the exemption can be worth tens or hundreds of thousands of dollars on a single sale. Claiming it correctly means understanding what qualifies, how the formula works, and what you have to file, even in years when no tax would be owed.

What Qualifies as a Principal Residence

The property doesn’t have to be a detached house. The Canada Revenue Agency accepts condominiums, cottages, apartments, duplexes, mobile homes, trailers, houseboats, and shares in a co-operative housing corporation.¹ For any year you want to designate a property, you must own it (alone or jointly), it must be a housing unit, and you, your spouse or common-law partner, a former spouse or common-law partner, or your child must have “ordinarily inhabited” it at some point during the year.

The ordinarily inhabited standard is looser than most people expect. Even a short stay during the calendar year can satisfy it, which is why a family that spends a few weeks each summer at a cottage can still designate the cottage for those years. If the main reason you own the property is to earn rental income, though, a brief personal stay won’t rescue it. Incidental rent on its own is fine; buying the place to rent it out is not.²

One Property Per Family Per Year

A family unit can designate only one property as a principal residence for any given tax year. The family unit is you, your spouse or common-law partner (unless you lived apart under a separation agreement for the whole year), and your children under 18 who were unmarried and not in a common-law partnership.² If you own both a city home and a cottage, you have to choose which one carries the designation for each overlapping year.

The choice matters most at sale. Years you don’t designate produce a taxable gain, so before selling either property, run the numbers and assign the designation to whichever home produced the larger gain per year of ownership. Keeping records of each property’s fair market value over time makes that calculation much easier when the moment arrives.

How the Exemption Formula Works

Section 40(2)(b) shelters the gain using a three-variable fraction:²

Exempt gain = A × (B ÷ C)

A is the total capital gain (proceeds minus adjusted cost base and selling expenses).
B is one plus the number of tax years after acquisition during which the property was your designated principal residence and you were resident in Canada. If you were not a Canadian resident in the year you acquired the property, the plus one is dropped.
C is the total number of tax years after acquisition during which you owned the property.

When B equals or exceeds C, the fraction is one and the whole gain is tax-free. That is the ordinary result for someone who buys a single home, lives in it throughout ownership, and stays a Canadian resident.

The Plus-One Year

The extra year in the numerator exists so that moving doesn’t cost you the exemption. When you sell one home and buy another in the same calendar year, both can be designated for that overlap year without either losing full shelter. The bonus year is only available if you were a Canadian resident during the year you acquired the property.³

A Partial Exemption Example

Say you owned a home for 10 years and designated it as your principal residence for 7 of those years, with the cottage taking the other 3. Your exempt fraction is (1 + 7) ÷ 10, or 80% of the total gain. The remaining 20% is a taxable capital gain, half of which gets added to your income.

Residency and Land Size Reduce the Shelter

The exemption only counts years you were a resident of Canada. Ownership years spent living abroad can’t be designated and drag down the exempt fraction, and if you were non-resident when you bought the property, the plus-one bonus year is unavailable too.³

The exemption automatically covers the housing unit and up to one-half hectare (about 1.24 acres) of the underlying land.² Anything larger is excluded from the exemption unless you can show the extra land was necessary for the use and enjoyment of the home. Lifestyle preference isn’t enough; you need something concrete such as a local zoning minimum, a prohibition on subdivision, or a placement of the house on the lot that requires the extra land for road access. When only part of the property qualifies, you split the proceeds and the adjusted cost base between the qualifying and non-qualifying portions, and the gain on the non-qualifying part is taxable.

Home Offices and Rental Corners

Using part of your home for business or rental income doesn’t automatically break the exemption. The CRA treats the whole property as retaining principal residence status when the business or rental use is minor relative to residential use, you haven’t made structural changes for the business, and you haven’t claimed capital cost allowance on the property.²

Claiming CCA is the mistake that does the real damage. The moment you deduct it on part of your home, the CRA treats that portion as sold at fair market value and reacquired, permanently splitting the property into a sheltered residential piece and a taxable business piece. Deducting utilities, insurance, or a share of property tax as home office expenses doesn’t cause this problem. CCA does.

Moving Out or Moving In: Change of Use Elections

When a property switches between personal and rental use, the default rule treats it as sold at fair market value and immediately bought back, which can trigger a taxable gain. Two elections defer that result.

Section 45(2): Converting Your Home to a Rental

If you stop living in your home and rent it out, a Section 45(2) election treats the property as though no change of use happened.⁴ It also lets you keep designating the property as your principal residence for up to four extra tax years after you move out, even though you no longer live there. If you moved because your employer required a relocation and your new workplace is at least 40 kilometres closer to your new home than the old one, the four-year cap is lifted entirely, provided you move back during that employment or within a year of it ending.² You cannot claim CCA while the election is in force without undoing the shelter.

Section 45(3): Moving Into a Former Rental

If you move into a property you had been renting out, a Section 45(3) election overrides the deemed disposition and lets you designate up to four preceding rental years as principal residence years. You make the election by filing a signed letter with your tax return for the year you eventually sell the property. It’s unavailable if you or your spouse claimed CCA on the property at any point after 1984.²

The Under-One-Year Flipping Rule

Since January 1, 2023, profit on a residential property you owned for fewer than 365 consecutive days is treated as business income, not a capital gain. That income is fully taxable and the principal residence exemption does not apply, regardless of what you intended when you bought. Exceptions exist for genuine life events such as death, disability, separation, job relocation, insolvency, or the birth of a child. Without a qualifying exception, a sale inside 12 months means full tax on the profit and no shelter.

Reporting the Sale

Even when the exemption wipes out the entire gain, you still have to report the sale. Since the 2016 tax year, failing to report the disposition and designate the property on your return means the CRA will not allow the exemption.³ Two documents go in with your T1 return for the year of sale:

Schedule 3 (Capital Gains or Losses) reports the disposition itself, including the proceeds, the adjusted cost base, and the resulting gain.
Form T2091(IND) designates the property as your principal residence for specific years and calculates the exempt portion.⁵

To fill in the forms you need the year of acquisition, the sale price, the adjusted cost base (the purchase price plus legal fees, land transfer taxes, and the cost of capital improvements such as additions or major renovations, but not routine maintenance), and the legal description from the deed.

Late Designation Penalties

If you forget to designate the property in the year you sold it, you can ask the CRA to accept a late designation by amending your return. The agency has discretion to accept, but a penalty applies. It’s the lesser of $8,000 or $100 for each complete month between the original filing deadline and the date the CRA receives your request in acceptable form.⁶ A two-month delay costs $200. Six and a half years hits the $8,000 ceiling. The penalty stings especially when no actual tax would have been owed had the form gone in on time, which is why reporting the sale in the same tax year it closes is the safest habit, exemption or not.

1
Canada Revenue Agency. What is a Principal Residence
2
Canada Revenue Agency. Income Tax Folio S1-F3-C2 – Principal Residence
3
Canada Revenue Agency. Line 12700 – Taxable Capital Gains – Principal Residence and Other Real Estate
4
Justice Laws Website. Income Tax Act – Section 45
5
Canada Revenue Agency. T2091IND Designation of a Property as a Principal Residence by an Individual (Other Than a Personal Trust)
6
Canada Revenue Agency. Reporting the Sale of Your Principal Residence for Individuals (Other Than Trusts)