What happens if another Ontario business starts using a name confusingly similar to my trademark?

If you hold a registered trademark and another business starts using a confusingly similar name, logo, or slogan for related goods or services, you generally have stronger tools to stop them than if your mark were unregistered. A registered mark under the Trademarks Act gives you the exclusive right to use it across Canada for the goods and services it covers, so a lawyer can typically send a cease-and-desist letter asserting infringement and, if that fails, pursue a court action seeking an order stopping the use and potentially damages or an account of profits.

Even without registration, you may still have recourse through the common-law tort of passing off if you can show your business has built up goodwill in the name, the other business's use is likely to confuse customers, and you have suffered or are likely to suffer harm — but this is generally harder and more expensive to prove than registered-trademark infringement. What counts as "confusingly similar" is not just about identical names; it also considers overall impression, the nature of the goods or services, and the channels each business sells through. An early legal assessment of the strength of the conflict is usually the practical first step.