T5008 box numbers (2025)
Securities transactions. One line per disposition, so an active trading account produces a summary running to dozens of pages.
The box numbers
| Box | What it is |
|---|---|
16 | Quantity |
17 | Identification of security |
20 | Cost or book value |
21 | Proceeds of disposition |
These are the CRA’s own numbers, printed on the paperwork itself. The list is what KeyGlance reads for the 2025 tax year, harvested from the tax software’s own templates rather than typed from memory.
What goes wrong reading one
The single worst document shape in a dropoff. The cost base is frequently blank on the slip, which means the number the return needs is not printed anywhere on the paper. A thirty-row broker summary also prints totals at the foot, and taking a printed total for a per-row value is the error that looks most plausible.
Where this sits in a return
Rollover and the CRA’s Auto-fill My Return already bring down the slips an issuer files with the CRA. What neither can reach is the paperwork nobody files — receipts, rental records, self-employment logs — and that is the part still being typed by a person. See Auto-fill's 500-slip ceiling.
What we do about it
KeyGlance reads a client’s dropoff as it arrives and enters it into TaxCycle, Taxprep Desktop, ProFile, Taxprep Cloud or DT Max on your own Windows machine. Every figure stays linked to the spot on the page it was read from, so you check it against the document instead of retyping it. It never files anything with the CRA.