A cease and desist (C&D) letter is a formal notice demanding that the recipient stop a specific activity — typically, conduct that infringes your intellectual property rights or damages your reputation. While C&D letters have no formal legal status (unlike a court order), they are a practical first step in IP enforcement and defamation disputes, signalling that you are aware of the problem and prepared to litigate if necessary. This guide covers the three most common contexts for C&D letters in Ontario: trademark infringement, copyright infringement, and defamation.

Trademark Infringement Under the Trade-marks Act

Canada's federal Trade-marks Act (TMA) gives registered trademark owners the exclusive right to use their mark in Canada in association with the goods and services for which it is registered (s. 19) and the right to prevent use of confusingly similar marks (s. 20). A C&D letter asserting trademark infringement should:

Note: In Canada, trademark rights arise through use as well as registration. Even without a CIPO registration, a business that has established significant common-law trademark rights through use in a geographic area can assert those rights in a C&D letter — though registered marks are significantly easier to enforce.

Copyright Infringement Under the Copyright Act

Canada's Copyright Act, RSC 1985, c C-42 grants copyright owners the exclusive right to reproduce, perform, publish, and translate their original works. Copyright in original works arises automatically upon creation — registration is not required, though it creates a rebuttable presumption of ownership and validity.

A copyright C&D letter in Ontario should:

Fair Dealing Caution: Before sending a copyright C&D, ensure the use is not protected by fair dealing (Canada's equivalent of fair use) under ss. 29–29.2 of the Copyright Act. Fair dealing for research, private study, education, parody, satire, criticism, review, or news reporting may be a complete defence. Sending an aggressive C&D over clearly fair-dealing use can expose you to costs in litigation.

Defamation: Libel vs. Slander in Ontario

Defamation involves the publication of a false statement of fact that injures the reputation of an identifiable person. In Ontario, defamation is governed primarily by common law, with the Libel and Slander Act, RSO 1990, c L.12 providing additional rules for broadcast and published media defamation.

The distinction between libel (written/permanent form) and slander (spoken form) matters in Ontario:

A defamation C&D should demand an immediate retraction or correction, removal of the defamatory content, and a written apology. Under the Libel and Slander Act, a newspaper or broadcaster that promptly publishes a retraction may limit their damages exposure — many defamation C&Ds are structured to trigger this remedy quickly.

What a C&D Letter Accomplishes

A well-drafted C&D letter accomplishes several things:

Limitations of DIY C&D Letters

While C&D letter templates can be a starting point, there are significant risks to self-drafting:

Escalation: When C&D Letters Fail

If the recipient ignores or disputes the C&D letter, escalation options in Ontario include: