This calendar lists, month by month, the 2026 tax deadlines of a self-employed person or a small business in Quebec: income tax return, instalments, GST/QST, source deductions and slips. Every date was checked on November 11, 2026 on canada.ca and revenuquebec.ca; the official links are below the table.
Weekends and holidays: when a due date falls on a Saturday, a Sunday or a public holiday, the CRA and Revenu Québec accept the return or payment on the next business day. The table gives the actual 2026 date when that rule applies.
The 2026 tax calendar, month by month
| Date in 2026 | Deadline | Who it applies to |
|---|---|---|
| The 15th of every month | Source deductions and employer contributions on the previous month’s payroll (CRA and Revenu Québec) | Employers who remit monthly |
| 1 month after each period | GST/HST and QST return and payment (period ending March 31: April 30) | Registrants who file monthly or quarterly |
| Thursday, January 15 | Revenu Québec source deductions and contributions: October to December 2025 (quarterly remitters) or all of 2025 (annual remitters) | Small employers |
| Monday, March 2 | 2025 T4, T4A and T5 slips (CRA); 2025 RL slips and RL-1 summary (Revenu Québec), with the labour standards contribution and, where applicable, the WSDRF contribution. February 28 fell on a Saturday. | Employers and payers of investment income |
| Monday, March 16 | First 2026 instalment (March 15 fell on a Sunday) | Individuals who must pay instalments |
| Wednesday, April 15 | Revenu Québec source deductions and contributions for January to March (quarterly remitters) | Small employers |
| Thursday, April 30 | 2025 income tax return, federal and Quebec TP-1; balance owing due for everyone, self-employed people included; GST/QST payment for individuals in business who file once a year (December 31 year-end) | All individuals |
| Monday, June 15 | 2025 return for self-employed people and their spouse; annual GST/QST return for individuals in business (December 31 year-end); second instalment | Self-employed people |
| Wednesday, July 15 | Revenu Québec source deductions and contributions for April to June (quarterly remitters) | Small employers |
| Tuesday, September 15 | Third instalment | Individuals who must pay instalments |
| Thursday, October 15 | Revenu Québec source deductions and contributions for July to September (quarterly remitters) | Small employers |
| Tuesday, December 15 | Fourth instalment | Individuals who must pay instalments |
| Thursday, December 31 | Single instalment for the year | Farmers and fishers |
Coming up: the fourth instalment on Tuesday, December 15, 2026, then the 2026 slips, due on Monday, March 1, 2027, because February 28, 2027 is a Sunday (Revenu Québec already says so).
Corporations: it depends on the year-end
A corporation does not follow April 30. Its return (T2 federally, CO-17 in Quebec) is due six months after the end of its tax year: for a year ending March 31, that is September 30. The tax balance is due two months after the year-end; federally, a Canadian-controlled private corporation (CCPC) that claimed the small business deduction and whose taxable income does not exceed its business limit has three months.
For GST/QST, a business that files once a year generally has three months after its year-end. Its GST/QST instalments, if any, fall on the last day of the month following each quarter of the fiscal year.
“GST payment dates” are not the same thing
The “GST payment dates” people search for are those of the credit the CRA pays to individuals: January 5, April 2, July 3 and October 5, 2026 (since July it is called the Canada Groceries and Essentials Benefit). This calendar gives the opposite: the dates when a business remits the GST and QST it collected.
Late: what it costs
- Income tax return filed late: 5% of the unpaid balance, plus 1% for each full month late, up to 12 months, federally and in Quebec. The CRA raises it to 10% and 2% a month, up to 20 months, for repeat late filers.
- Interest: it runs on any balance unpaid after April 30, even when a self-employed person’s return is only due June 15. The CRA compounds it daily.
- GST/HST return filed late (CRA): 1% of the amount owing, plus a quarter of that 1% for each full month late, up to 12 months.
- Source deductions remitted late to the CRA: from 3% (1 to 3 days) to 10% (more than 7 days).
- Late payment or remittance to Revenu Québec: 7% up to 7 days, 11% for 8 to 14 days, 15% beyond.
- Slips: at least $100 for T4 slips filed late; $100 for each piece of information missing from an RL-1 slip.
Even if you cannot pay it all, file on time: the late-filing penalty would come on top of the interest.
Getting ready for each deadline
The 2026 tax instalments calculator gives the four payments; the GST/QST registration threshold tool tells you whether registration has become mandatory; the Quebec payroll and source deductions guide explains what to remit on the 15th.
InnoBooks adds up the GST and QST you collect and pay as invoices and expenses come in: when the due date arrives, the GST/QST sales tax summary is already ready. Try InnoBooks free.
Official sources (checked November 11, 2026)
- CRA — Important dates for individuals
- CRA — Instalment due dates
- CRA — GST/HST reporting requirements and deadlines
- CRA — Payroll remittance due dates
- CRA — When to file T4 and T4A slips
- CRA — When to file the T2 corporation return
- CRA — Corporations: balance-due day
- CRA — Late-filing penalty
- CRA — Benefit payment dates
- Revenu Québec — Deadline for filing your income tax return
- Revenu Québec — Making instalment payments
- Revenu Québec — GST/HST and QST filing frequency
- Revenu Québec — Frequency of remittances and due dates
- Revenu Québec — Filing RL slips and the RL-1 summary
- Revenu Québec — Corporation income tax, CO-17 (in French)
- Revenu Québec — Late-filing penalties
Renting out a dwelling on December 31? The RL-31 slip is added to your slips: see Revenu Québec’s RL-31 page.