What return of capital actually is
Return of capital (ROC) is a distribution that isn’t drawn from the fund’s income or gains — it’s a portion of your own invested capital coming back to you. Because it isn’t a profit, it isn’t taxed in the year you receive it. It shows up in box 42 of your T3.
It reduces your ACB
Every dollar of ROC reduces your adjusted cost base by a dollar. That deferral is the whole point: you aren’t taxed now, but a lower ACB means a larger capital gain when you eventually sell. ROC is a timing benefit, not a tax exemption.
When ACB goes negative
If cumulative ROC exceeds your original cost, your ACB would go below zero. The CRA doesn’t allow a negative cost base: the negative amount is treated as a capital gain in the year it happens, and your ACB resets to zero. Long-held high-ROC holdings (some REITs and income funds) can hit this, producing a taxable gain in a year you didn’t sell.
Why it’s easy to miss
ROC never appears as a transaction in your brokerage account — no buy, no sell, just a lower cost base you’re expected to track yourself across years and distributions. Multiply that by several funds and it’s one of the most commonly missed adjustments in Canadian investment tax.