Principal residence exemption: (1 + years designated) ÷ years owned

How does the exemption formula work?

Paragraph 40(2)(b) reduces the gain on a home by A × B ÷ C, where A is the gain before the exemption, B is one plus the years designated as the principal residence while your client was resident in Canada, and C is the years owned laws-lois.justice.gc.ca. Both counts only include taxation years that end after the acquisition date. If B equals C or more, the whole gain is exempt.

The "plus 1" exists because a client who sells one home and buys another in the same year lived in both that year, but can only designate one of them canada.ca. The extra year covers the overlap, and it only applies if your client was resident in Canada during the year the home was bought canada.ca.

A home qualifies for a year if your client, a current or former spouse or common law partner, or a child lived in it at some time during that year canada.ca. It can be a house, cottage, condominium, apartment, trailer, mobile home or houseboat, and the land under it usually counts up to half a hectare (1.24 acres). Extra land counts only if your client shows it was needed to use and enjoy the home, for example a municipal minimum lot size laws-lois.justice.gc.ca.

How is the sale reported on the return?

Since the 2016 tax year, the CRA only allows the exemption if the disposition is reported on the return canada.ca. For a 2025 sale, that means Schedule 3 plus Form T2091(IND), even when the whole gain is exempt canada.ca.

A property owned for less than 365 consecutive days doesn't go here at all. Since January 1, 2023, the residential flipping rule treats the profit as business income and removes the exemption, unless the sale is tied to a listed life event such as death, separation of at least 90 days, or an eligible work relocation canada.ca. The details are on the property flipping rule page.

How much of a cottage gain is exempt? A worked example

Your client's family owns a city home and a cottage. The cottage was bought in 2016 for $300,000 and sold in 2025 for $680,000, with $30,000 of selling costs. The family designates the cottage for 2016 to 2019 and keeps the other years for the city home.

The 50% inclusion rate applies because the proposed increase was cancelled; see the 2026 inclusion rate page. The cost of the choice shows up later: 2016 to 2019 are gone for the city home, so when it sells, those four years reduce its B. Run both properties before you pick the years, because the right answer is usually the home with the higher gain per year.

The "plus 1" in action: a client who bought a condo in 2019 and moved to a new house in 2025, selling the condo that same year, owned the condo for 7 years (2019 to 2025). Designating 2019 to 2024 gives B of 1 + 6 = 7, so the condo gain is fully exempt and 2025 stays free for the new house laws-lois.justice.gc.ca. That return only needs box 1 on Schedule 3 and page 1 of T2091(IND) canada.ca.

What happens if the sale was never reported?

If your client forgot to designate in the year of sale, ask the CRA to amend that return. The CRA says it will accept a late designation in certain circumstances, but a penalty may apply canada.ca. The late designation is deemed an election under 220(3.21)(a.1), so 220(3.2) lets the CRA accept it if your client applies within ten calendar years after the end of the year laws-lois.justice.gc.ca.

The penalty under 220(3.5) is the lesser of $8,000 and $100 for each complete month from the original due date to the date of the request laws-lois.justice.gc.ca. A designation filed 14 complete months late costs $1,400. One filed seven years late hits the $8,000 cap.

The bigger risk is the open year. Under 152(4)(b.3), an unreported disposition of real property can be reassessed after the normal reassessment period, and once your client reports it on an amended return, the CRA has three years from that filing laws-lois.justice.gc.ca. The normal periods are on the reassessment period page.

Who shares the one home a year limit, and what else trips clients up?

For 1982 and later years, only one home can be designated for the year across your client, a spouse or common law partner for the whole year (unless living apart under a judicial separation or written separation agreement), and children who were unmarried and under 18 laws-lois.justice.gc.ca. A client who was unmarried and under 18 also shares the limit with parents and unmarried siblings under 18. For years before 1982, each spouse could designate a different home canada.ca.

Turning a home into a rental, or a rental into a home, is a change in use and a deemed disposition at fair market value. A 45(2) election lets your client keep designating the home for up to four years while renting it out, and a 45(3) election lets your client designate a former rental for up to four years before moving in canada.ca. See the change in use page for the elections and the CCA trap.

A client who bought the home while not resident in Canada loses the "plus 1", and only years of Canadian residence count in B canada.ca. Holding past 365 days doesn't settle it either: for a property that isn't flipped, whether the profit is business income or a capital gain is still a question of fact canada.ca.