Canada: Where Are All The Patent Re-examinations In Canada?

Last Updated: December 13 2013
Article by Cameron Weir

Re-examination is the only post grant procedure available in the Canadian Patent Office that allows a third party to challenge the validity of a Canadian patent. From its inception in October 1989, up to September 2013, there have been only 79 re-examination requests in Canada. This figure contrasts sharply to the situation in the U.S., where post grant proceedings in the U.S. Patent Office are much more frequent. This article provides some background on the re-examination process in Canada, discusses its limitations and also compares and contrasts re-examination to the other main post-grant procedure for attacking an issued patent in Canada, namely patent impeachment.


Re-examination is provided for in sections 48.1-48.5 of Canada's Patent Act ("the Act").

Pursuant to section 48.1 of the Act, any person may request a re-examination of any claim in an issued patent by filing prior art consisting of patents, published applications, and printed publications with the Commissioner of Patents. The request for re-examination must also include written submissions setting forth the pertinency of the prior art and the manner of applying the prior art to the claims in issue.

A request for re-examination may be made at any time after a patent has issued, until the expiration date of the patent. Once the request is made, the Patent Office will forward a copy of the request to the patentee. A re-examination board is then established and makes a determination as to whether a substantial new question of patentability affecting any claim of the patent in issue has been raised in the request. This determination is made within 3 months.

Where it is determined that a substantial new question has not been raised, the board will notify the requesting party and its decision in this regard is final for all purposes and is not subject to appeal or review by any court. Of the 79 re-examination requests made in Canada, no substantial new question of patentability was found in 19 cases.

Where, however, it is determined that a substantial new question has been raised in the request, the patentee is notified and has 3 months to file a reply to the notice setting out submissions on the new question of patentability.

In response to the notification, the patentee may suggest amendments to the claims at issue, submit new claims or cancel certain claims, so long as the scope of the claims is not broadened as compared to the claims of the original patent.

Upon receipt of a reply, or in the absence of a reply from the patentee, the re-examination board causes the re-examination process to be initiated. The board must render a decision as to patentability of the claims at issue within 12 months from the date that the board commenced the re-examination process. The board's decision may be appealed to the Federal Court, but only by the patentee.

If the board decides to cancel one or more of the claims, the patent is deemed to have been issued from its date of grant, but in its corrected form. If all the claims are cancelled, the patent is deemed to never have been issued. If a new claim is incorporated, or a claim is amended, the new or amended claim is effective from the date of the issued re-examination certificate and will remain valid until the expiry of the patent term.

In approximately two thirds of all re-examination board decisions to date, at least one claim at issue was cancelled or amended.


Pursuant to section 60 of the Act, proceedings for impeachment may be brought against any issued patent before the Federal Court and may be instituted by any interested person. "Interested person" has been interpreted broadly by the Court, and can include, for example, a party which may expect to have the patent asserted against it (e.g. in view of the manufacture or sale of a product in Canada which may arguably fall within the scope of the patent). Receipt of a cease and desist letter from the patentee is typically not a pre-requisite to commencing such a proceeding.

In an impeachment proceeding, the burden is on the interested person to prove that the patent or one or more of the patent's claims are invalid or void. An impeachment proceeding can raise any ground of invalidity, including obviousness and novelty attacks based on prior art and technical grounds pertaining to certain intrinsic defects in the patent itself.

An impeachment proceeding is typically brought by way of action. An action in the Federal Court includes the following basic steps:

  1. Pleadings: In the pleadings, the parties set out the relief sought, and particulars as to allegations made (including all bases for invalidity alleged). It can also be expected that the patentee would counterclaim for infringement.
  2. Documentary Discovery: Each party is required to serve a list of relevant documents. Copies of non-privileged documents are exchanged.
  3. Oral Discovery: Usually a party has the opportunity to examine a single representative of an adverse party. Inventors of the patent in issue may also be examined.
  4. Pre-Trial Steps: Pre-trial steps may include a mediation or other court-directed settlement meeting, exchange of expert reports, and setting of a trial date.
  5. Trial: A trial in the Federal Court is conducted before a judge who decides all legal and factual issues.

Typically, an impeachment action will require 2-3 years to complete. However, if pursued aggressively, it is possible to have the action completed within two years. A decision of the Federal Court may be appealed to the Federal Court of Appeal by either party.

Re-examination versus Impeachment

Re-examination is a relatively quick and inexpensive procedure for third parties to challenge the validity of a patent. However, it is subject to important limitations, which may account (in part) for the relatively few re-examinations in Canada to date. Importantly, once the process is initiated, a third party does not have the opportunity to make further submissions with respect to the patentability of the existing claims, or any amended or new claims. Moreover, as noted above, only the patentee has a right of appeal, and there is no opportunity to appeal a finding of the re-examination board that no substantial new question affecting patentability of any claim has been raised by the request for re-examination. Further, only patents, applications and printed publications may be submitted for review on re-examination. Therefore, prior uses and sales, and other important validity issues such as utility and sufficiency, cannot be raised during a re-examination.

For these reasons, in important cases, it may be preferable for a third party to proceed by way of a patent impeachment action, in which all invalidity issues may be raised, discovery may be pursued, evidence (including expert evidence) may be adduced, and detailed submissions may be made to a judge for consideration. Weighing against these advantages are the cost and timeline. Because the impeachment action is a contested proceeding before the Federal Court, and may also involve a counter-claim for infringement brought by the patentee, the costs associated with an impeachment action are significantly higher than those associated with a re-examination proceeding and the timeline may be significantly longer.


Whether re-examination or a patent impeachment action is commenced depends largely on an assessment of issues such as cost, timing, and the relative importance of initiating an attack on an issued patent. Experienced patent counsel can help determine which procedure might be most advantageous in any given situation. Overall, the narrow scope of re-examination in Canada is often a deciding factor in choosing between these two alternatives.

If you have any questions regarding the above, please do not hesitate to contact a member of our firm's Patents group.

The preceding is intended as a timely update on Canadian intellectual property and technology law. The content is informational only and does not constitute legal or professional advice. To obtain such advice, please communicate with our offices directly.

The preceding is intended as a timely update on Canadian intellectual property and technology law. The content is informational only and does not constitute legal or professional advice. To obtain such advice, please communicate with our offices directly.

To print this article, all you need is to be registered on

Click to Login as an existing user or Register so you can print this article.

Cameron Weir
Similar Articles
Relevancy Powered by MondaqAI
In association with
Related Topics
Similar Articles
Relevancy Powered by MondaqAI
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of

To Use you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions