T5008 and Schedule 3: How to Report Capital Gains in Canada
Your T5008 gives you proceeds and a broker-reported cost figure. Schedule 3 asks for your true adjusted cost base under Canadian tax law.
What the T5008 is and is not
The T5008 is an annual slip from your broker listing securities you sold. It is useful, but it is not a substitute for your own ACB calculation. Box 20 is the broker's cost or book value figure, not necessarily the figure the CRA wants you to use.
What Schedule 3 actually asks for
Schedule 3 asks for proceeds of disposition and adjusted cost base for each property or grouped position. The CRA expects your ACB under ITA s. 47 pooling rules, not just the broker's book value. The difference matters most when you have multiple lots, superficial losses, cross-account positions, options, or USD holdings.
The reconciliation problem
Your T5008 may show several separate disposals for a security you accumulated over time. Schedule 3 often needs one reconciled figure: total proceeds, pooled ACB, and net gain or loss. That means you must combine all purchases and dispositions across all relevant accounts before you file.
How ActiveACB bridges the gap
ActiveACB takes your full broker export, applies pooled ACB rules, superficial loss adjustments, FX calculations, options linking, and corporate-action handling, then outputs the exact figures you need for each Schedule 3 line. It turns broker activity into tax-ready totals instead of leaving you to reconcile slip summaries by hand.
Frequently asked questions
Do I enter each T5008 slip separately on Schedule 3?
Not necessarily. Many taxpayers group dispositions by security or broker report where that produces the correct total proceeds and ACB. What matters is that the figures reported on Schedule 3 are correct, not that they mirror the slip line-for-line.
My T5008 Box 20 is blank. What do I do?
You still need to report the disposition. A blank Box 20 means the broker did not provide a cost figure. You must calculate the ACB yourself from your trading history.
What if I have dispositions at multiple brokers?
You need all relevant broker data in one calculation. For example, combine your IBKR export with the Questrade workflow described at IBKR Canada tax guide or Questrade T5008 guide so the ACB is calculated across the full picture.
The numbers on my T5008 add up to the same as ActiveACB. Do I still need to recalculate?
If the totals match, your file may simply be straightforward. Recalculating is still the way to confirm that no pooled-cost, FX, or superficial-loss adjustments were missed.