Nobody likes losing money on an investment. But what if those losses could actually work in your favour at tax time? That's the idea behind tax-loss harvesting — a strategy that turns paper losses into real tax savings. In this article, we'll explain what tax-loss harvesting is, how it works, the rules you need to follow in Canada, and when it makes sense to consider it.
What is tax-loss harvesting?
Tax-loss harvesting is the practice of selling investments that have dropped below their purchase price to realize a capital loss. You can then use that loss to offset capital gains you've earned elsewhere in your portfolio, reducing your overall tax bill.
In Canada, only 50% of capital gains are included in your taxable income — this is called the inclusion rate. Capital losses you harvest also offset gains at that same 50% rate.
This strategy only works in non-registered (taxable) accounts. Registered accounts like Tax-Free Savings Accounts (TFSAs) and Registered Retirement Savings Plans (RRSPs) are already tax-sheltered, so there's no capital gains tax to offset inside them.
If your capital losses exceed your capital gains in a given year, you can carry those unused losses back up to 3 years or forward indefinitely to offset gains in other tax years.
How does tax-loss harvesting work?
The process can be broken down into a few straightforward steps:
Identify underperforming investments — look through your taxable account for holdings that are currently worth less than what you paid for them.
Sell to realize the loss — by selling the investment, you turn an unrealized (paper) loss into a realized capital loss that can be reported on your tax return.
Use the loss to offset capital gains — apply the realized loss against any capital gains you've earned during the year. If your losses exceed your gains, carry the remainder back or forward.
Reinvest in a similar — but not identical — asset — to stay invested in the market, purchase a comparable security in the same sector or asset class. It's important that this replacement isn't considered identical to the original, or the Canada Revenue Agency (CRA) may deny your loss.
The superficial loss rule in Canada
The CRA has a rule designed to prevent investors from selling an investment solely to claim a loss and then immediately buying it back. This is called the superficial loss rule.
If you — or someone affiliated with you, such as a spouse or a corporation you control — buy the same or an identical investment within a 61-day window (30 days before and 30 days after the sale), the CRA will deny the loss.
When a loss is denied under this rule, it isn't gone forever. The disallowed loss gets added to the adjusted cost base (ACB) of the replacement investment, which may reduce your capital gain (or increase your loss) when you eventually sell that replacement.
To avoid triggering the superficial loss rule:
Wait at least 31 days before repurchasing the same investment
Buy a similar but not identical security — for example, an exchange-traded fund that tracks the same sector rather than the exact same stock
Ensure affiliated persons (such as a spouse) don't purchase the identical investment within the 61-day window either
Tax-loss harvesting example
Say you invested $5,000 in an energy company last year, but today it's worth $4,000. You can sell that investment, claim the $1,000 capital loss, and use it to offset capital gains from other investments.
To stay invested in the energy sector, you could purchase an energy-sector exchange-traded fund or shares in a different energy company. This keeps you exposed to potential rebounds in the sector without running afoul of the superficial loss rule.
Benefits of tax-loss harvesting
The most immediate benefit is a lower tax bill. By offsetting capital gains with harvested losses, you keep more of your investment returns rather than sending them to the government.
There's a compounding benefit, too. The money you save on taxes stays invested in your portfolio, where it can grow over time. Thanks to the power of compounding, the gains on those deferred taxes can meaningfully contribute to your long-term returns.
Because unused losses can be carried forward indefinitely, tax-loss harvesting gives you flexibility. You can stockpile losses in a down year and deploy them against gains whenever it makes sense.
Drawbacks of tax-loss harvesting
Tax-loss harvesting isn't without its complications. Finding a replacement investment that's similar enough to keep your portfolio on track — but different enough to avoid the superficial loss rule — can take some effort.
There are also transaction costs to consider. Selling and buying investments may trigger trading fees, and the replacement security might not perform exactly like the one you sold.
Because everyone's financial situation is different, it's wise to consult a tax professional or financial advisor before harvesting losses. They can help you navigate the rules and make sure the strategy makes sense for your circumstances.
When to consider tax-loss harvesting
Year-end is the most common time to review your portfolio for harvesting opportunities, since capital gains and losses are reported on an annual basis. But it doesn't have to be a once-a-year exercise.
Market downturns can create opportunities throughout the year. When prices drop broadly, there may be more unrealized losses in your portfolio to harvest.
If you're already planning to rebalance your portfolio, it's a natural time to look for tax-loss harvesting opportunities. You can sell underperforming holdings and reinvest in a way that aligns with your target allocation.
Keep in mind that for a loss to count in a given tax year, the trade must settle before December 31. In Canada, stock trades typically settle 1 business day after the trade date (known as T+1), so plan accordingly.
