Single Administration of Ontario Corporate Tax

The Governments of Canada and Ontario signed a Memorandum of Agreement on October 6, 2006, that will lead to the Canada Revenue Agency (CRA) administering most of Ontario's corporate taxes.

Ontario businesses will benefit from one form, one set of rules, one audit, one appeals process and one point of contact.

The CRA will administer the following corporate taxes on behalf of Ontario:

  • Corporate income tax
  • Corporate minimum tax
  • Capital tax
  • Special additional tax on life insurers

Ontario will continue to administer:

  • Mining tax
  • Insurance premiums tax
  • Electricity Act payments-in-lieu of federal and Ontario corporate taxes

Single administration will take effect for tax years ending after December 31, 2008. This means that:

The CRA will assume some responsibilities for tax years ending before December 31, 2008 as a means of providing early compliance gains to business. From April 2008, the CRA will start:

  • auditing Ontario Corporation Tax Returns (CT23) at the same time as the federal Corporation Income Tax Return (T2) with a view to all audits being integrated by 2009;
  • processing objections and appeals related to CT23 returns; and
  • providing rulings and interpretations to corporations on CT23 matters.

What does this mean for businesses?

Major Milestones


The Canada Revenue Agency is committed to keeping stakeholders informed on a timely basis when major milestones in planning and implementation are reached.

Regular updates on the CRA's single administration of Ontario's corporate income tax will continue to be posted on the CRA Web site at

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