Thought Leadership, Research & CPA Spotlights

Bill C-59: What CPAs Need to Know

Updated April 30, 2026

Bill C-59, Fall Economic Statement Implementation Act received royal ascent and took effect on June 20, 2024. It brought significant amendments to the Competition Act aimed at addressing misleading claims about environmental and social benefits also known as “greenwashing”. The amendments place the burden on organizations making environmental or social claims to substantiate that such claims are based on adequate and proper testing, in accordance with internationally recognized methodologies. Bill C-59 also granted private parties the option to bring greenwashing complaints directly to the Competition Tribunal.

In March 2026, Bill C-15, An Act to implement certain provisions of the budget table in Parliament on November 4, 2025, introduced two key amendments to the Bill C-59 provisions:

Removal of "international standards": Businesses no longer need to use an "internationally recognized methodology" to substantiate environmental claims. They now only need to meet the more flexible "adequate and proper substantiation" standard.
Removal of private parties' right to bring complaints directly to the Competition Tribunal, leaving the Competition Bureau with sole enforcement authority.

What changes does Bill C-59 introduce?

Bill C-59 amends section 74.01 of the Competition Act to address misleading environmental and social benefit claims made to the public. Specifically, the amendments pertain to:

Any statement, warranty or guarantee of a product’s benefits for protecting or restoring the environment or mitigating environmental, social, and ecological causes or effects of climate change that are not based on adequate and proper testing.
Any representations with respect to the benefits of a business or business activity for protecting or restoring the environment or mitigating the environmental and ecological causes or effects of climate change that are not based on adequate and proper substantiation in accordance with internationally recognized methodology.

The amendment to the Competition Act results in a significant change where the Commissioner of Competition needed to rely on the general misleading advertising provisions of the Competition Act and bore the burden of proving that the environmental or social claims were materially false or misleading. With the introduction of Bill C-59, the onus is now placed on the advertiser to prove, if they are challenged, that the claims are based on adequate and proper testing or substantiation.

What does "adequate and proper" testing mean?

While “adequate and proper” is not defined in the Competition Act, the Competition Bureau guidelines suggest it depends on the context and the general impression of the claim. Generally, it requires that testing be conducted before the claim is made and that the claim is backed by objective, scientific proof that reflects real-world use.

Who will be impacted by these new provisions?

All companies in Canada, irrespective of whether they are public or private, will be impacted by these new provisions in the Competition Act.

Who can take action under the amendments to the Competition Act?

The Competition Commissioner can take action in accordance with these amendments to the Competition Act, which places the burden of proof on businesses to substantiate their environmental claims.

What is the role of CPAs?

The skillset and ethical obligations of CPAs position the profession to help ensure that environmental and social information disclosed by organizations is both reliable and credible.

CPAs understand the strong governance and internal controls necessary to support the “adequate and proper” testing of a claim, and how to create and maintain supporting evidence so third parties could independently assess the veracity and reliability of the representation made by the company.

What are CPA’s professional obligations in relation to Bill C-59?

CPAs are required to act with integrity and due care, meaning CPAs have an obligation to ensure that environmental and social claims made by their organizations are accurate, substantiated and not misleading.

CPAs should only undertake work and responsibilities that they have the competency to perform. If the CPA does not have the necessary knowledge and skills required to substantiate an organization’s environmental and social claims, reaching out to an expert in the field may be necessary.

CPAs are obligated to not associate themselves with information that they know or should know is false or misleading.

For more information on potential ethical issues CPAs need to watch out for in sustainability reporting, refer to our article: Greenwashing and Litigation.