Strategic Considerations: Canadian Post-grant Patent Administrative Procedures

• Published date: 10 December 2025
• Subject Matter: Intellectual Property, Patent
• Law Firm: Smart & Biggar
• Author: Ms Julia London and Nicole Boyle

The Canadian patent system provides multiple post-grant administrative procedures that allow patentees and third parties to challenge or amend Canadian patents without requiring legal proceedings before the courts. While these mechanisms are narrower than those available in the United States, they can be of strategic value in particular circumstances.

Re-examination

Section 48.1 of the Patent Act provides that any person, including the patentee, may request re-examination of one or more claims of a granted patent at any time during its term. The request must be based on prior art patents, published applications, or printed publications, and must explain how the cited art applies to the challenged claims. Accordingly, parties can only use re-examination to challenge the validity of a patent based on anticipation or obviousness.

For third-party patent challengers, re-examination can provide a more summary and less costly option compared to an impeachment action in the Federal Court; however, the circumstances where re-examination is likely to yield a desirable outcome for the third-party are relatively limited (as discussed in further detail below).

Stage 1 - Threshold review

Once a request is filed, the Re-examination Board (the "Board") considers whether the request raises a "substantial new question of patentability" relating to the validity of one or more claims.

If the threshold is not met, the requester is notified with reasons. The Board's determination of this threshold question is final and is not subject to appeal or judicial review. Third-party involvement (if any) ends once the request is filed; only the patentee may participate thereafter.

Stage 2 - Re-examination

If the threshold criterion is met, the patentee is notified and has three months to provide responding submissions and/or propose amendments to the patent (provided...