What is a deemed disposition and when does the CRA apply it?

Why the tax system needs a fictional sale

Canada's capital gains system only taxes a gain when property is disposed of. Without a special rule, someone could hold an asset indefinitely, pass it to the next generation, move it out of the country, or change how they use it, and never trigger the tax that has been quietly accruing on paper the whole time. A deemed disposition closes that gap: at specific events defined in the Income Tax Act, the property is treated as sold at its fair market value and immediately reacquired at that same value, crystallizing whatever gain or loss had built up, without an actual buyer, seller, or transaction.

The five situations below cover the vast majority of deemed dispositions a small business owner or individual is likely to encounter.

Emigration: departure tax

When you stop being a Canadian resident, section 128.1 deems you to have sold most of your property at fair market value the day you leave, an event commonly called departure tax. Canadian real estate, registered accounts, and a handful of other categories are excluded, and an election under form T1244 lets you defer payment of the resulting tax without interest until the property is actually sold. We cover this event on its own in what is departure tax in Canada.

Death

Under subsection 70(5), you are deemed to have disposed of all your capital property immediately before death, at fair market value, which is why a person's final tax return so often includes a significant capital gains calculation even if nothing was actually sold during their lifetime. Property left to a surviving spouse or a qualifying spousal trust can roll over at cost instead, under subsection 70(6), which defers the tax until the spouse eventually disposes of the property or passes away themselves.

Change in use of a property

Converting a property from personal use to income-producing use, or the reverse, triggers a deemed disposition under section 45 at the fair market value on the date the use changes. The most common example is converting a principal residence into a rental property, or converting a rental back into a personal residence. Two elections soften this: subsection 45(2) lets you defer the deemed disposition when you start renting out a former home, and in some circumstances preserves the principal residence exemption for several additional years even while the property earns rent; subsection 45(3) works the other way, deferring the disposition when a rental property becomes your personal residence again.

Gifts to non-arm's-length persons

Under subsection 69(1), if you give property away, or sell it for less than fair market value, to someone you do not deal with at arm's length, such as a family member, you are deemed to have disposed of it at fair market value regardless of what was actually paid or received. This prevents gains from being shifted to a lower-income relative simply by transferring property below its real value. A gift to a spouse or common-law partner is an exception and generally rolls over at cost automatically, unless you elect out of that treatment.

The 21-year rule for trusts

Most personal trusts, including many family trusts, are deemed to dispose of their capital property every 21 years under subsection 104(4), whether or not any property has actually left the trust. Without this rule, a trust could hold appreciating property forever and defer capital gains tax across generations. Trustees typically plan around the 21-year mark well in advance, distributing appreciated property to beneficiaries beforehand, since that transfer can itself use a rollover at cost rather than triggering the trust-level deemed disposition.

Why a fresh cost base matters after the event

A deemed disposition is not only about the tax owing on the way in; it also resets the property's cost base for whatever comes next. Once the deemed sale and reacquisition happen, the property's new cost is its fair market value at that moment, not the original purchase price. This matters most on departure tax, where a properly filed T1243 establishes a bumped-up cost base that a destination country, if it recognizes the deemed disposition, will use going forward, avoiding double taxation on the same growth later. It matters just as much after a death, where the beneficiary who eventually sells inherited property is taxed only on growth from the date-of-death value onward, not from whatever the deceased originally paid decades earlier.

Losing track of this reset is one of the more expensive mistakes we see: an heir or a returning resident who cannot document the deemed proceeds from an earlier event risks being taxed on the entire historical gain, including years that were already dealt with, simply because the paperwork from the original deemed disposition was never kept.

The valuation problem behind every deemed disposition

Every deemed disposition hinges on one number: fair market value at the trigger date. Public securities are straightforward, since a closing price on the relevant date settles the question. Private company shares, real estate held outside Canada, closely held partnership interests, and collectibles are not, and disagreements over valuation are one of the most common sources of dispute between taxpayers and the CRA on these files. Getting an independent valuation, or at minimum a defensible internal calculation with supporting documentation, at the time of the triggering event is far cheaper than reconstructing one years later during a review.

How we handle this

We treat each deemed disposition trigger as its own planning event rather than a surprise line on a return: modelling the numbers before an emigration date is set, reviewing a will's rollover provisions before it is needed, timing a change-in-use election when a property's purpose is about to change, and flagging an approaching 21-year trust anniversary years ahead of the deadline. This planning work runs alongside our business advisory services and our departure tax guide for clients leaving Canada specifically.

Source: CRA — Trust deemed disposition rules.