What is the superficial loss rule in Canada?

What the rule actually denies

Under the superficial loss rules, a capital loss is denied if two conditions are both met: you sell a property at a loss, and you or an affiliated person acquires identical property during the period starting 30 days before the sale and ending 30 days after it, and that identical property is still owned at the end of that window. The rule targets one specific pattern: selling something purely to crystallize a tax loss while never really giving up the position, because the same or an equivalent holding is bought right back.

Affiliated persons reach well beyond just you. The rule applies if the repurchase is made by your spouse or common-law partner, a corporation you control, a trust in which you or your spouse is a majority beneficiary, or, importantly for investors, your own RRSP, RRIF or TFSA. Selling a stock at a loss in a taxable account and buying the same stock back inside your TFSA a week later triggers the rule just as much as buying it back in the same taxable account would.

"Identical property" is also narrower than people expect. Shares of the same company bought back in the same class count, and units of the exact same mutual fund or ETF count, but a different fund from a different provider tracking a similar index generally does not, even if the two funds behave almost identically day to day. This distinction is what makes it possible to stay invested in a market or sector through the waiting period without necessarily giving up the loss.

What happens to the denied loss

When the rule applies in an ordinary taxable account, the loss is not simply gone. It is added to the adjusted cost base of the repurchased shares, which reduces the eventual gain, or increases the eventual loss, whenever those shares are finally sold for good. In effect, the tax benefit is deferred rather than eliminated, as long as the repurchase happened in a normal taxable account where cost base tracking still applies.

The important exception is a repurchase inside a registered account like a TFSA or RRSP. Because adjusted cost base does not function the same way inside these plans, the denied loss cannot simply be added to the cost base of the shares sitting in the registered account. In that situation, the loss is effectively lost for good, with no future offset available. This is the single most expensive way to run into this rule, and it catches investors who think of their TFSA and taxable account as separate worlds rather than one connected picture for tax purposes.

How this compares to the US wash-sale rule

Investors who also hold US accounts often already know the US wash-sale rule, and the two rules share the same basic 30-day-before-and-after structure, adding up to a 61-day window around the sale. The Canadian rule reaches further in one respect: it explicitly captures a spouse, a controlled corporation, and registered accounts, which the US rule handles differently. Someone managing accounts on both sides of the border should not assume that clearing the US wash-sale rule in a US account also clears the Canadian superficial loss rule if a Canadian spouse or a Canadian registered account is involved in the repurchase.

Why the sale date is not always the day you click sell

For superficial loss purposes, the relevant date is generally the settlement date of the trade, not the trade date you place the order on. Since the move to T+1 settlement for most securities, a trade placed near the end of December settles only a business day later, but the exact cutoff for a trade to settle within the current calendar year still depends on market holidays and each broker's own processing, so anyone doing year-end tax-loss selling should confirm the specific cutoff date with their broker rather than assuming a fixed calendar date every year. Placing a loss trade too close to year-end, only to have it settle in January, can push the loss into the wrong tax year entirely.

How to actually use tax-loss selling without tripping the rule

The straightforward way to avoid the rule is to wait out the full 30-day window on both sides before repurchasing the identical security, in any account, including a spouse's or your own registered plans, and the same waiting period applies to crypto holdings just as much as it does to stocks. An alternative some investors use is buying a similar but not identical security to maintain market exposure during the waiting period, then switching back afterward if they still want the original holding; this needs care, because a similar ETF tracking the same index is not automatically the same as buying back the exact same fund, and the line between similar and identical is where most mistakes happen.

It is also worth remembering that the rule only denies a loss; there is no equivalent rule that defers a gain when you sell winning positions and buy them straight back. That asymmetry is exactly why tax-loss selling near year-end gets so much attention while the same repurchase pattern around a gain draws no scrutiny at all.

How we handle tax-loss selling for clients

We look at a household's accounts together, taxable, spousal, and registered, before recommending a tax-loss sale, because the rule cares about the whole household's activity, not just the account where the loss was realized. Where the numbers support it, we also flag the settlement-date timing early enough in December that a trade actually lands in the intended tax year. This sits alongside the broader question of what an active trader can deduct, and our day trader tax services page covers both together for active accounts.

Source: CRA — Superficial losses.