Sell a losing stock, rebuy it a few days later, and the Canada Revenue Agency may quietly erase your capital loss. This guide walks through how the superficial loss rule works, why selling and rebuying inside your RRSP does not dodge it, and the cross-border exchange-rate twist most Canadians miss.
In the United States it is called the wash-sale rule. In Canada, the equivalent lives in the Income Tax Act: section 54 defines a "superficial loss," and paragraph 40(2)(g)(i) deems that loss to be nil. Two conditions have to line up for a loss to be caught:
Both must be true. The window is counted in calendar days both directions, so it spans 61 days in total — the 30 days before, the trade date itself, and the 30 days after. A common misconception is that only the days after the sale matter; a repurchase in the month leading up to the sale counts just as much.
The rule would be trivial to sidestep if it only watched your own trading account. It does not. "Affiliated person" is defined in section 251.1, and the CRA's administrative position extends it to your registered plans. That means a "sell it in the cash account, rebuy it in the RRSP" manoeuvre does not escape the rule — the repurchase inside the RRSP is a purchase by an affiliated person.
| Who buys the identical shares in the window | Affiliated with you? | Loss caught? |
|---|---|---|
| You, in another taxable account | Yes | Yes |
| Your spouse or common-law partner | Yes | Yes |
| Your RRSP or TFSA | Yes (CRA position) | Yes |
| A corporation you control | Yes | Yes |
| An adult child, sibling, or parent (arm's length) | Generally no | Generally no* |
*Arm's-length family members are typically not "affiliated" for this specific rule, but other tax rules — attribution, gifting, and beneficial-ownership tests — can apply, so this is not a loophole to lean on.
Here is the part that surprises people: in a normal taxable account, a superficial loss is deferred, not destroyed. Under paragraph 53(1)(f), the denied loss is added to the adjusted cost base (ACB) of the repurchased shares. You get it back later, when you eventually sell those shares for good.
A worked example. Suppose you:
XYZ at $50, for a $5,000 ACB.The $1,000 loss is superficial and denied for now. Instead of vanishing, it is added to the new ACB: $4,100 + $1,000 = $5,100. If you later sell those shares at $60 ($6,000), your capital gain is $6,000 − $5,100 = $900, not $1,900. The loss was preserved — it simply moved into the cost base of the shares you still hold.
The exception is brutal and permanent: if the repurchase happens inside a registered account (RRSP or TFSA), there is no ACB to add the loss to, because registered plans do not track cost base for capital-gains purposes. The loss is denied and there is nowhere for it to go. It is gone forever. That single detail is why the "rebuy in the RRSP" idea is worse than doing nothing.
The rule only bites on the same or identical property. Shares of the same class of the same company are identical — full stop. But two different securities that happen to move together are not.
This is why fund substitution is a widely used tax-loss-harvesting technique. Two exchange-traded funds that track the same benchmark — say, a broad S&P/TSX index — but are issued by different providers are generally not identical property to each other. Investors often sell the fund sitting at a loss, immediately buy a comparable fund from a different issuer to hold similar market exposure, and thereby realize the loss without tripping the superficial loss rule. The CRA has indicated that units of separate funds are not identical even where their underlying holdings overlap heavily. This is a description of how the mechanics work, not a suggestion to act — the details matter and can change.
For US-listed holdings, capital gains and losses must be computed in Canadian dollars. You convert the cost at the exchange rate on the purchase date and the proceeds at the rate on the sale date — the CRA generally accepts the Bank of Canada rate for each transaction date. Because the two legs use two different exchange rates, a currency move can create or erase a capital loss even when the US-dollar price never moved.
An illustration. You buy 100 shares of a US-listed stock at USD $100 when 1 USD = 1.30 CAD:
$13,000$12,500$500 capital loss in Canadian dollars, purely from FX.Reverse the currency move — the loonie weakens to 1.35 — and the same flat US-dollar trade produces a $500 gain instead. The lesson: a Canadian's real, reportable gain or loss on a foreign security is the CAD figure, and the superficial loss test is applied to that CAD amount. An FX-driven loss is still a loss the rule can deny.
This is general educational information, not tax or investment advice, and it does not tell you to buy or sell anything. Real situations add wrinkles the summary above skips — partial dispositions, multiple tax lots at different costs, settlement-versus-trade-date timing, options and other "rights to acquire," and how the ACB add-back attaches to whichever affiliated person actually holds the repurchased shares. Rates, thresholds, and CRA positions can change. Confirm your specific facts with a qualified tax professional or directly with the CRA before filing.
Quintarthai's screener and holdings watchlist flag cross-listed TSX/NYSE pairs — such as a name quoted on both exchanges — so you can see when a security you hold is the same underlying company in two currencies, and keep your positions organized for tax-lot awareness across accounts. The platform surfaces filings and market data for research; it does not calculate your taxes or provide tax advice.
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