Generally, corporations carrying on business through a permanent establishment in Ontario are liable for both federal and Ontario corporate taxes.

Who is liable for Ontario corporate tax?

Generally, incorporated businesses that have a permanent establishment in Ontario are liable for Ontario corporate tax. A permanent establishment is generally a fixed place of business such as an office, farm, factory, branch, warehouse, etc.

Unincorporated businesses are not liable for Ontario corporate tax. These include sole proprietorships and businesses run by individuals as partnerships. Owners of unincorporated businesses are however, liable for personal income tax on an individual basis.

Business registration

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Ontario corporation number and Ontario corporations tax account number

The Ontario corporation number is issued by the Ontario Ministry of Public and Business Service Delivery. This number is required to file your Corporations Information Act annual return. For tax years ending on or after January 1, 2009, Ontario corporations and foreign business corporations licensed to carry on business in Ontario could file this annual return with the Canada Revenue Agency.

On May 15, 2021, the Canada Revenue Agency stopped accepting corporations’ annual returns on behalf of the Ontario Ministry of Public and Business Service Delivery. Corporations who have an annual return due after October 18, 2021 must file their annual returns, which they can now do directly in the Ontario Business Registry.

More about the Ontario Business Registry and Annual returns

In most cases the Ontario corporations tax account number is automatically generated after the information is received from the Ontario Ministry of Public and Business Service Delivery.

Read on: How to register with the Ontario Ministry of Finance (the ministry) for an insurance premium tax account number.

Federal business number

The federal business number is issued by the Canada Revenue Agency. This number is required to file your T2 corporation income tax return (T2 return) with the Canada Revenue Agency.

How to get a business number

Read on: the business number and your Canada Revenue Agency accounts

Filing a corporate tax return

For tax years ending on or after January 1, 2009, you will file one harmonized T2 return including all the Ontario schedules with the Canada Revenue Agency.

More about the T2 corporation income tax return.

Generally, every corporation carrying on business in Ontario through a permanent establishment must file the T2 return with the Canada Revenue Agency no later than six months after the end of the tax year. The T2 return and applicable schedules would include the following Ontario corporation taxes: corporate income tax, including refundable tax credits, corporate minimum tax and the special additional tax on life insurance corporations.

Where to send your T2 return.

Adjustments

For tax years ending on or after January 1, 2009, send your adjustment request or amended return to the Canada Revenue Agency.

How to request a reassessment of your T2 return

For tax years ending on or after January 1, 2009, make your corporate tax payments to the Canada Revenue Agency.

More about payments to the Canada Revenue Agency

Instalments

You may be required to make instalment payments, which are partial payments of the total amount of tax payable for the year. The balance of tax, which is the tax payable for the tax year after you have deducted the instalments already made for the year, is paid on your balance due date, which is generally three months after the end of the tax year for a Canadian-controlled private corporation or two months after the end of the tax year for a non Canadian-controlled private corporation.

More about payments, instalment calculations and due dates for tax years ending on or after January 1, 2009

Assessments

For tax years ending on or after January 1, 2009, the Canada Revenue Agency processes all T2 returns (these returns include necessary Ontario schedules). The Canada Revenue Agency conducts the audit reviews and sends out all assessments and reassessments.

Corporate tax reassessment period

For tax years ending on or after January 1, 2009, the normal reassessment period is as follows:

  • For a Canadian-controlled private corporation, it is the period that ends three years after the mailing date of the original notice of assessment.
  • For a non-Canadian-controlled private corporation, it is the period that ends four years after the mailing date of the original notice of assessment.

More about reassessments for tax years ending on or after January 1, 2009

For tax years ending on or after January 1, 2009, you can file an objection with the Canada Revenue Agency within 90 days of the day the Canada Revenue Agency sent the notice of (re)assessment.

Download form T400A, Notice of Objection - Income Tax Act from the Canada Revenue Agency

Administration

The Canada Revenue Agency administers Ontario's corporate income tax, corporate minimum tax and the special additional tax on life insurers.

Questions

Contact the Canada Revenue Agency with your questions about Ontario corporate tax at 1-800-959-5525 or 1-800-665-0354 for teletypewriter (TTY).

Advance tax rulings or technical interpretations

Requests for advance tax rulings or technical interpretations should be sent to the Canada Revenue Agency.

More about advance income tax rulings

T2 Returns and Guides for tax years ending on or after January 1, 2009 from the Canada Revenue Agency

Frequently Asked Questions