Ontario Small Business CRA Deadline Calendar for 2026
Keeping track of CRA deadlines can feel overwhelming for small business owners in the Niagara Region. Between running daily operations, managing cash flow, and trying to grow your business, it is easy to miss an important filing or payment date.
This month-by-month CRA deadline calendar gives you a clear overview of the most common filing and remittance deadlines Ontario small businesses face in 2026. Use it as a quick reference to stay organized and avoid penalties. For full details on HST specifically, see our complete 2026 HST filing guide.
January 2026
- January 31: Final quarterly HST payment and return due for the October to December 2025 period (quarterly filers).
- January 31: T4 and T4A slips must be issued to employees and contractors for the previous year.
- January 31: Employer Health Tax (EHT) annual return due if applicable.
February 2026
- February 28: T4 Summary must be filed with the CRA.
- Last day of February: RRSP contribution deadline for the 2025 tax year.
March 2026
- March 15: Corporation income tax return (T2) due for corporations with a December 31 fiscal year-end (if balance owing).
- March 31: Final instalment payment for corporations with a December 31 year-end.
April 2026
- April 30: Personal income tax return (T1) due for self-employed individuals and sole proprietors. Payment of any balance owing is also due on this date.
- April 30: HST return and payment due for the January to March 2026 quarter (quarterly filers).
- April 30: Annual HST return and payment due for businesses that file annually with a December 31 year-end.
May 2026
- May 1: Payroll remittances due for April payroll (if you have employees).
- Mid-month: Corporate instalment payments may be due depending on your fiscal year.
June 2026
- June 15: Personal income tax return filing deadline for self-employed individuals (payment still due April 30).
- June 30: Corporation income tax return due for corporations with a March 31 fiscal year-end.
July 2026
- July 31: HST return and payment due for the April to June 2026 quarter (quarterly filers).
August 2026
- Mid-August: Corporate instalment payments may be due.
September 2026
- September 30: Corporation income tax return due for corporations with a June 30 fiscal year-end.
October 2026
- October 31: HST return and payment due for the July to September 2026 quarter (quarterly filers).
November 2026
- Mid-November: Corporate instalment payments may be due.
December 2026
- December 31: End of the 2026 calendar year. Prepare for year-end reconciliations.
- December 31: Last day to make certain business expense claims for the year.
Important notes: These dates are based on standard December 31 fiscal year-ends. If your business has a different fiscal year-end, some deadlines will shift. When deadlines fall on a weekend or holiday, they typically move to the next business day; always confirm with the CRA or your bookkeeper.
Local tip from a Niagara bookkeeper: Many businesses in the Niagara Region are seasonal: tourism, agriculture, wineries, and event companies often see big cash flow swings between summer and winter. Planning ahead using this calendar helps you set aside money during busy months so you are not caught short when April or July HST payments are due.
Frequently Asked Questions
Are these deadlines the same every year?
Many deadlines follow the same pattern each year, but always double-check with the CRA or your bookkeeper because dates can shift when they fall on weekends or holidays.
What happens if I miss a CRA deadline?
Late filings and payments usually trigger penalties and daily interest. The sooner you file and pay, the lower the penalty usually is.
Do I need to use a bookkeeper to meet these deadlines?
Not necessarily, but having professional support greatly reduces the risk of mistakes and missed dates, especially as your business grows. See our full list of bookkeeping services.
Never Miss a CRA Deadline Again
We keep all your filings and remittances on track all year long: HST, payroll, and more. Serving businesses across Niagara Falls, St. Catharines, Fort Erie, Welland, and the surrounding Niagara Region. View our plans.