Patent infringement and the Patent Act in Canada

The patent system in Canada is a creature of statute—it was created by legislation. The Patent Act defines your rights as a patentee (patent holder) and available legal remedies whether your startup experiences patent infringement or commits it.

Rights of a patentee in the Patent Act

The exclusive rights granted to a patentee are set out in section 42 of the Patent Act, which states, in part:

“Every patent granted under this Act shall…grant to the patentee and the patentee’s legal representatives for the term of the patent, from the granting of the patent, the exclusive right, privilege and liberty of making, constructing and using the invention and selling it to others to be used, subject to adjudication in respect thereof before any court of competent jurisdiction.”

The Patent Act does not define infringement but the case-law surrounding patent infringement has interpreted the above rights to mean the patentee has the right to full enjoyment of a monopoly for the invention as defined by the patent specifications and limited in time to a period of 20 years.
Thus, patent infringement occurs when a patentee or the patentee’s legal representatives have been deprived of their full enjoyment of the monopoly, in whole or in part, directly or indirectly.
As with all civil causes of actions, it is the responsibility of the person wronged to enforce their rights. Patent enforcement typically occurs through demand letters, negotiations, media attention and, more often than not, litigation.

Determining patent infringement

Patent infringement is a question of both law and fact. The factual component relates to what has in fact been done by the alleged infringer and the question of law revolves around interpreting the claims of the patent. It is worth noting that the intention of the defendant is immaterial to whether infringement has occurred. Everyone is deemed to have notice of an issued patent and patents are presumed to be valid.
The correct method for determining infringement is to compare the allegedly infringing product to the issued patent. The plaintiff’s physical product is not relevant to the analysis. Since it is the invention as claimed in the patent which defines the scope of the monopoly, the court’s first task is to construe the claims.
The court must determine the essential and non-essential elements of each claim. The essential and non-essential elements of a claim are compared to the allegedly infringing item or method.
When all the essential elements of any one claim are present, infringement has occurred. There is no patent infringement if an essential element is different or omitted. A difference, addition or omission of a non-essential element does not prevent a finding of infringement. Again, the court only looks for all the essential elements to be present in the allegedly infringement item.

Remedies as cited in the Patent Act

Section 55 of the Patent Act states: “A person who infringes a patent is liable to the patentee and to all persons claiming under the patentee for all damage sustained by the patentee or by any such person, after the grant of the patent, by reason of the infringement.”

Liabilities of patent infringement

A party who infringes a patent faces a number of liabilities, including:

  • An interim/interlocutory injunction
  • A permanent injunction
  • Damages or an accounting of profits
  • Legal costs
  • Pre- and post-judgment interest*
  • Delivery of and destruction of infringing goods

*Interest is payable on the amount of the awarded judgment and is calculated from when litigation began until payment is received.


If you believe someone is infringing your patent, first carefully compare the allegedly infringing item to the claims of your patent. If you discover that all the essential elements of any one of your claims exist in the infringing item, then you will need to take steps to enforce your patent. For this reason, it is often said that a patent is merely a license to litigate.
Note: The content in this article is for purposes of general information only. It is not legal advice.


Canadian Intellectual Property Office. (2011, April 27.) Retrieved May 3, 2011, from
Canadian Legal Information Institute. (2005, May 14.) Patent Act, R.S.C. 1985, c. P-4. Retrieved May 3, 2011, from