All Ontario incorporated businesses need to file a T2 corporate tax return. The date for when these tax assessments are due depends on your articles of incorporation which determine your fiscal year.

Ontario Corporate Tax Deadlines

For all businesses filing their tax return, these deadline dates come into effect exactly 6 months after the end of your fiscal year. For example, if your fiscal year ends on April 13, then your tax assessment would be due on October 13.

An important note for newly incorporated businesses: Your first taxable year is most likely going to be determined by the number of days rather than a year. For example, if you incorporate your business on May 4 and declare your fiscal year to be August 15th, your first taxable year would be the number of days between May 4th and August 15th. Any subsequent tax years would be annually starting from August 15th onward.

Corporate Tax Returns in Ontario

As a business filing your corporate T2 tax return, it is crucial to know how to file your tax assessment. You can either file them electronically or by mail and address the package to Canada Revenue Agency:

International and Ottawa Tax Services Office
2204 Walkley Road
Ottawa, ON K1A 1A8

Please note that all businesses who cross a $1 million income threshold must file their corporate T2 tax return digitally.

Corporate Taxes Owing in Ontario

In most cases with tax returns, your corporation might have some taxes owing. There are plenty of deductions and tax credits available to you to make the most out of your tax return. If your business has taxes owing, you can make a lump payment or pay in partial payments throughout the following fiscal year.

Payment instalment deadlines

If you have any tax owing, you may have to pay corporate tax instalments. These instalments are quarterly payments due on:

  • March 15th
  • June 15th
  • September 15th
  • December 15th

Get Help with Your Corporate Taxes in Ontario

Tax season is a stressful season for any corporation filing their taxes. To get the most out of your finances and grow your business, it is best to trust the tax experts of a professional for any tax inquiry. The tax experts at T2inc are here to help you sort through your year-end returns.

Contact us today for ease of mind in your next tax assessment.

Frédéric Roy-Gobeil


As President of T2inc.ca and an entrepreneur at heart, I have founded many start-ups such as delve Labs and T2inc.ca. A former tax specialist at Ernst & Young, I am also a member of the Ordre des comptables professionnels agréés CPA and have a master's degree in taxation from the Université de Sherbrooke. With a passion for the world of entrepreneurship and the growth mindset, I have authored numerous articles and videos on the industry and the business world, as well as on accounting, taxation, financial statements and financial independence.

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