What's the difference between a T4 and a T4A?
A T4 reports employment income for employees. A T4A reports other income like contractor/self-employed payments, pensions, or certain scholarships.
When are T4A slips due to contractors?
Generally the last day of February following the tax year — file early enough to confirm delivery before the deadline.
What if I'm missing some of these documents?
Gather what you can and flag the gaps to your accountant early — the CRA's My Business Account portal can help you retrieve missing slips and remittance summaries.
Is this checklist different in the US?
Yes — see the US version of this checklist, which covers 1099s/W-2s and quarterly estimated taxes instead of T4/T4A slips and CRA instalments.