Canada Revenue Agency published a reference guide on business filing and payment deadlines.
The point of the reminder is that business tax deadlines do not all follow one calendar. Income tax, GST/HST, payroll, and instalment obligations can each run on different rules.
For corporations, CRA said income tax instalments are generally required monthly or quarterly when total tax is more than $3,000.
GST/HST deadlines depend on the reporting period. Annual, quarterly, and monthly filers each have different filing and payment schedules, so a business cannot assume that one due date covers all remittances.
CRA also noted that GST/HST annual filers may have to make quarterly instalment payments if net tax is $3,000 or more in both the previous fiscal year and the current fiscal year.
The agency illustrated the instalment point with a business whose 2024 fiscal-year net tax was $4,000 and whose 2025 fiscal-year net tax was expected to be at least that much.
For small businesses, the practical risk is not only missing a return. A business can file an income-tax return on one schedule, owe GST/HST on another, and still have instalment obligations that arise before the final return is due.
The article belongs in business because deadline management affects cash flow, interest, penalties, and compliance risk even when the underlying tax liability is not disputed.