Firstly, you can choose to work only with a franchisor who is a member of the Canadian Franchise Association. Secondly, you can be wary of the following warning signs:

• Slick salesperson trying to pitch a fast sale
• Pressure for franchisees to sign gag orders
• Insistence on cash transactions only
• Exaggerated earnings
• Promising a proven business model or proprietary technology that doesn't exist
• Promising training that never materializes
• Forcing franchisees to spend money on so-called improvements
• Failure to provide disclosure

It's never a bad idea to contact a franchise lawyer and get their opinion on the legitimacy of a potential franchisor.