Superficial Loss Rule in Canada: a plain-English guide with worked examples
Sold a stock at a loss and bought it back too soon? Canada has a rule that quietly cancels your tax deduction — and most investors don't realise it until their accountant tells them in April. Here's what the Superficial Loss Rule actually says, three worked examples in real dollars, and the TFSA/RRSP trap that costs Canadians thousands every year.
What is the Superficial Loss Rule?
If you sell a security at a loss and then you (or someone affiliated with you) buy the same security back within 30 calendar days before or after the sale, the Canada Revenue Agency (CRA) treats that loss as a superficial loss. In plain English: you can't claim the loss on your taxes.
The window is 30 days each way, so you're effectively dealing with a 61-day quarantine period — 30 days before the sale, the day of the sale itself, and 30 days after.
The loss isn't gone forever. It gets added to the adjusted cost base (ACB) of the new shares you bought. So you eventually realise the loss when you finally sell those new shares for good. But for this tax year? The deduction is denied.
Who counts as you? (the “affiliated persons” trap)
This is the part Canadians get wrong most often. The rule isn't just about you repurchasing the stock — it covers anyone the CRA considers affiliated with you. That includes:
- Your spouse or common-law partner
- A corporation you control
- A trust where you're the majority beneficiary
- Your TFSA or RRSP (yes, even though they're registered accounts — see Example 2)
- Your spouse's TFSA or RRSP
Crucially: adult children, parents, and siblings are NOT affiliated for this purpose. Only spouses and entities you control.
Example 1 — The straightforward case
Sarah sells Shopify, buys it back 10 days later
In June, Sarah sells 100 shares of SHOP.TO at $80 to crystallise a loss before year-end. She had bought them at $100 each.
Ten days later, SHOP drops further and she can't resist — she buys 100 shares back at $75.
Because she bought within 30 days, this is a superficial loss. Her $2,000 loss is denied for this tax year. But it's not gone — it gets added to the cost base of her new 100 shares:
Net effect: Sarah can't claim the $2,000 loss this year. When she eventually sells the new shares, her cost base is $9,500 instead of $7,500, so the loss surfaces then. The taxman isn't denying it forever — just delaying it.
Example 2 — Selling in non-registered, buying in a TFSA (the trap)
Mike thinks he's being clever — and gets burned
Mike sells 200 shares of ENB.TO in his regular (non-registered) brokerage account for a $3,000 loss. He's planning to claim the loss against his other capital gains this year.
A week later, he likes Enbridge again and re-buys 200 shares — but this time inside his TFSA, thinking that "different account" means the rule doesn't apply.
Worse: because the new shares are inside a registered account, the denied loss cannot be added to the TFSA's cost base (registered accounts don't track ACB for tax purposes). The loss is effectively lost permanently.
Net effect: Mike forfeits the entire $3,000 deduction. This is the single most expensive mistake Canadians make with tax-loss harvesting.
Example 3 — Your spouse buys the same stock
Priya sells RBC for a loss. Her husband buys RBC the next week.
Priya sells 50 shares of RY.TO for a $1,200 loss in November. She doesn't plan to repurchase.
Two weeks later, her husband Aman — using his own brokerage account and his own money — decides RY.TO looks like a great deal and buys 50 shares. Neither of them realised this matters.
It does. Spouses are affiliated. Priya's $1,200 loss is denied. The $1,200 is added to the cost base of Aman's new 50 shares.
Net effect: Priya can't claim the loss this year. Aman's ACB is higher, so when he eventually sells, the loss surfaces on his return. Same family, but the loss has moved to a different person's tax return.
Stop tracking this in a spreadsheet.
LucidStocks flags superficial-loss conflicts automatically across all your accounts — including your spouse's, your TFSA, and your RRSP — and tells you when it's safe to repurchase.
Try LucidStocks free →How to avoid it (three real strategies)
1. Wait 31 days, full stop.
The simplest approach: sell, then don't buy back for at least 31 calendar days. Note your spouse and your TFSA/RRSP also have to wait. The loss is fully deductible this year, and you keep your original entry plan.
2. Buy a similar-but-not-identical security.
The rule applies only to identical properties. If you sell XEQT.TO and buy VEQT.TO (different ETF, similar exposure), it doesn't trigger the rule. Same idea for switching between two Big-5 Canadian bank stocks. The CRA's test is whether the security is the same one, not whether the exposure is the same.
3. Sell the loss before contributing to a TFSA/RRSP.
If you're planning a TFSA or RRSP contribution and want to harvest a loss on the same security in your non-registered account, sell the non-registered shares first AND make sure your registered-account repurchase happens more than 30 days later. Or buy a different security in the registered account.
How this differs from the US Wash-Sale Rule
Americans have a similar rule called the Wash-Sale Rule, but with two important differences:
- The US version only applies to non-registered (taxable) accounts. Your IRA buying back the stock is fine. Canada is stricter — your TFSA/RRSP repurchase still triggers it.
- The US rule covers "substantially identical" securities, which is broader than Canada's "identical" test. US tax courts have ruled on countless close cases. Canada is more literal: it's the same security or it isn't.
If you're a Canadian holding US stocks in a US brokerage account, BOTH rules can apply to the same trade. Most tax-software tools handle the US side but completely ignore the Canadian side — another reason to use a tool that knows both.
FAQ
Does this rule apply to crypto?
Yes. The CRA treats cryptocurrency as a commodity, and the superficial-loss rules apply to capital losses on crypto just like they apply to stocks. Sell Bitcoin at a loss, buy it back within 30 days, and the loss is denied.
What about dividends I received during the 30-day window?
Dividends are taxed separately and aren't affected by the superficial-loss rule. You still report and pay tax on the dividend in the year you received it.
If my loss is denied, when do I actually get to use it?
When you sell the new (repurchased) shares without triggering another superficial loss. The denied loss was added to your ACB, so it surfaces as a larger loss (or smaller gain) on the eventual sale.
Does the 30-day count include weekends and holidays?
Yes. The 30 days are calendar days, not trading days. A sale on December 15 is in the window until January 14.
What if I bought partial shares within the window?
The denied loss is proportional. If you sold 100 shares at a loss and bought back only 30 within the window, 30% of your loss is denied (and added to the ACB of those 30 new shares); 70% remains deductible.
One tool, both sides of the border.
LucidStocks is the only retail investing app that automatically flags Superficial Loss conflicts across spouses, TFSAs, and RRSPs — and US Wash-Sale conflicts too. Built by Canadians who got tired of pretending Canada was a US state.
Try LucidStocks free →Disclaimer: This article is for educational purposes only and is not tax or financial advice. Tax rules change, and your individual situation may differ. For decisions about your own taxes, consult a Canadian tax professional (CPA or qualified tax preparer). LucidStocks provides tools that help you track and identify tax events, but the responsibility for accurate filing is yours.