Unlike salaried employees, self-employed workers must send quarterly payments to both CRA and Revenu Québec. Missing them costs money immediately.
When Are Instalments Required?
Federal: if net tax owing exceeded $3,000 in either 2024 or 2025. Quebec: threshold is $1,800. Both are checked independently.
2026 Due Dates
- Federal and Quebec: March 15, June 15, September 15, December 15, 2026
Three Calculation Methods
Prior-year: Pay 25% of last year's owing each quarter — safest; CRA won't charge interest if followed exactly.
Current-year: Estimate current income and pay accordingly.
No-calculation: Follow CRA's instalment reminder amounts.
Missing Payments
CRA charges ~9% annual interest compounded daily. On a $5,000 missed payment, that's ~$450 in annual interest — easily avoidable.
Cash Flow Strategy
Set aside 25–30% of every client payment immediately into a dedicated tax savings account. Automate this transfer and the instalment stress disappears entirely.