The rule
A capital loss is superficial — and denied — when three things line up: you dispose of property at a loss; you or an affiliated person acquire the identical property within the period running from 30 days before to 30 days after the disposition; and you or the affiliated person still hold it at the end of that period. Affiliated persons include your spouse or common-law partner and corporations you control — selling from your account while your spouse buys the same coin the same week is squarely inside the rule. "Identical property" for crypto means the same asset: BTC for BTC. One coin swapped for a genuinely different one is not identical — though how far that reasoning stretches across wrapped and derivative versions of the same exposure is exactly the kind of question that stays with an adviser.
The landing: denied is not destroyed
Here is what makes Canada's answer unique among our four: the denied loss is added to the adjusted cost base of the reacquired property. The tax benefit is not cancelled — it is deferred into the new position, and comes back when you eventually dispose of it for real. Compare the four models now on this site: the US statute is written for stock or securities, so asset classification controls — not a blanket crypto exemption. The UK rewrites the disposal mechanically against the repurchase. Australia asks why you did it and attaches penalties to the wrong answer. Canada denies the loss without asking why — no purpose test, no penalty for trying — and quietly gives it back later through the ACB. Wide net, soft landing.
In Canada the wash-sale question has no "why". The calendar and the family tree answer it — and the consolation prize is written into your cost base.
Where holders actually get caught
The 30-days-before leg. Most people watch the rebuy window and forget the rule also looks backward: accumulating a position and then selling part of it at a loss within 30 days of a purchase can trip the rule with no "rebuy" at all.
The affiliated buyer. Spousal accounts and personal corporations are the classic misses. The rule was written for exactly that choreography.
DCA into a falling market. Automatic weekly buys mean there is almost always an acquisition within 30 days of any loss sale. Recurring-buy users harvesting losses in a drawdown are tripping this rule constantly, and their software often is not checking.
ACB bookkeeping after denial. The denied loss must actually be added to the new ACB — skip that entry and you eventually overpay, having lost the loss twice.
Working with the rule, honestly
- Harvesting a loss means a real 30-day exit, on both sides of the sale — across every account you and your affiliates hold.
- Check the calendar before the sale, not after. The rule is mechanical; so is the fix. A sale delayed a week is often the whole difference.
- Switching to a different asset works — a genuinely different coin is not identical property. Whether it is genuinely different exposure is your investment question, and whether it is genuinely different property is, at the margins, an adviser's.
- When the rule bites anyway, book the ACB adjustment. The loss is waiting inside the position. Make sure your records know it.
This page explains a computational rule. It is not advice on your transactions, and reading it creates no professional relationship.