What is a T5008?
A T5008 (Statement of Securities Transactions) reports securities you disposed of during the year. Your broker files one with the CRA and gives you a copy. Each slip lists what was sold, when, and for how much — the key boxes being box 21 (proceeds of disposition) and box 20 (cost or book value).
Proceeds (box 21) are generally reliable. The problem is box 20.
Why box 20 is blank, wrong, or misleading
Brokers are not required to compute your adjusted cost base, and often they cannot do it correctly even if they try. Box 20 is frequently:
- Blank — the broker simply didn’t populate a cost base.
- Book value, not ACB — an internal figure that ignores the adjustments the CRA requires.
- Account-limited — it reflects only the position held with that broker, not your pooled cost across every account.
- Missing adjustments — it rarely accounts for reinvested distributions, return of capital, or FX on US-dollar trades.
What you actually report
On your return you report the correct proceeds and the correct adjusted cost base, which flow through Schedule 3. Proceeds usually match the slip; the cost base should be your own pooled ACB. Where the two disagree, keep a record of how you arrived at your figure — that is what supports it if the CRA asks. This figure ultimately appears on Schedule 3.
If you receive multiple T5008s across brokers for the same security, remember they each see only part of the picture. Your true cost base pools all of them.
Reconciling slips against your records
Reconciliation means lining up each reported disposition against your own trade history: confirming the proceeds, supplying the right cost base where the slip is blank, and flagging anything that doesn’t match — a missing slip, a duplicate, or a cost base that ignores your DRIPs and return of capital. Done before you file, it turns a stack of slips into numbers you can defend.