The concept of restraint of trade represents one of the oldest and most contested areas of employment law, rooted in the fundamental tension between two competing interests that courts have grappled with for centuries. On one side stands the right of every individual to earn a living, to deploy their skills and experience in the marketplace, and to move freely between employers as their career develops. On the other side stands the legitimate interest of businesses in protecting the investments they make in developing confidential information, cultivating customer relationships, and training employees who gain access to trade secrets and proprietary methods. Canadian law approaches this tension with a strong presumption against restrictions that limit a person's ability to work after leaving an employer, requiring that any such restrictions meet stringent tests before courts will enforce them. For business owners, sole proprietors, and non-profit operators across Canada, understanding this legal framework is essential both when hiring employees who may bring knowledge from competitors and when seeking to protect their own operations from the departure of key personnel.
The doctrine of restraint of trade emerged from English common law principles that Canadian courts inherited and have since adapted to reflect contemporary employment relationships and modern business realities. At its core, the doctrine holds that any contractual provision that restricts a person's freedom to carry on their trade, profession, or business is prima facie void as against public policy. This means that the starting point for any analysis is that such restrictions are unenforceable, and the burden falls squarely on the party seeking to enforce the restriction to demonstrate that it should be upheld. This is a significant departure from the ordinary rules of contract law, where courts generally enforce agreements that parties have freely entered. The special treatment of restraint of trade provisions reflects a long-standing policy concern that individuals should not be prevented from using their skills and experience to support themselves and their families, and that the economy benefits from the free movement of labour and expertise between enterprises.