A corporation incorporated under the laws of any province or territory outside of Ontario (an "extra-provincial corporation") planning to carry on business in Ontario will be subject to the requirements of the Extra-Provincial Corporations Act (“EPCA”) and the Extra-Provincial Corporations Act General Regulation and the Corporations Information Act.

The EPCA defines an extra-provincial corporation as "a corporation, with or without share capital, incorporated or continued otherwise than by or under the authority of an Act of the Legislative Assembly". This definition includes corporations incorporated anywhere outside Ontario, but excludes such non-corporate vehicles such as partnerships.