The business publishing the claim is responsible, whoever drafted the words — and Canadian law puts the burden of proof on you, not a regulator.
Short answer
The business publishing the claim is responsible for it, whether a person or an AI tool drafted the words — and if the claim is about performance, Canadian law puts the burden of proof on you, not on a regulator to catch you.
The Competition Act singles out performance claims for a reversed burden of proof: it's reviewable conduct to make “a representation to the public in the form of a statement, warranty or guarantee of the performance, efficacy or length of life of a product that is not based on an adequate and proper test thereof, the proof of which lies on the person making the representation.” (Competition Act, s.74.01(1)(b)) In practice that means, as Treadstone Law's own advertising guidance puts it for Ontario businesses generally: “You cannot test after the fact if challenged.” The testing has to exist before the claim is published, AI-drafted or not. (Treadstone Law, Advertising and Marketing Law for Ontario Businesses)
AI copywriting tools are tuned to sound persuasive, and persuasive marketing language leans toward strong, specific-sounding performance numbers — a claimed percentage faster, a claimed fraction of the cost — which is precisely the category the Competition Act singles out. The tool has no way of knowing whether that number is actually tested; it's producing fluent language, not evidence. The Competition Bureau's own discussion of AI notes the same dynamic from the enforcement side — AI “eases the ability to scale” this kind of conduct once it starts. (Competition Bureau, Artificial intelligence and competition) A court order on this civil track can also carry a real penalty: for a corporation, up to $10,000,000 for a first order and $15,000,000 for each order after that, or three times the benefit derived, or 3% of worldwide gross revenues if that can't be determined. (Competition Act, s.74.1(1)(c))
Review any AI-drafted number or comparative claim against your own test data before it goes live, and keep the test on file — the onus is yours to carry, not the regulator's to disprove. See also whether the ad itself needs to disclose AI involvement and the same accountability question for a live conversation rather than published copy.
See how brand voice and quality control get checked before a claim ever ships.
