Kevin A. Jarzyna
BScE (Mechanical Engineering) Registered Patent Agent in Canada;
works with Moffat & Co and Macera & Jarzyna in Ottawa, Canada.
E-mail: [email protected]

Keywords: Canada, Patents, Examination Practice, Excess Claims

With the amendments to the Canadian Patent Rules now in effect, Applicants are now faced with the possibilities of Requests for Continued Examination and Excess Claim fees. This article outlines the different challenges presented, as well as some possible strategies to implement going forward.


On October 3, 2022, amendments to the Canadian Patent Rules came into effect. The amendments introduced excess claim fees for more than 20 claims on file at any time after the request for examination is filed and the need to file Requests for Continued Examination (RCE), with an additional fee, to continue examination once a third office action has been issued. One goal of these new rules is to streamline the examination process and reduce the number of patent applications pending.

These changes are related to the recent Canada-United States-Mexico Agreement (CUSMA), which requires that Canada adopt a new patent term adjustment (PTA) system by January 1, 2025. The new PTA system will compensate patent owners for “unreasonable delays” in the processing of their patent applications. The Canadian Patent Office is therefore encouraged to greatly reduce prosecution time.


Excess fees for claims in excess of 20 are aimed to limit the number of claims in an application, while RCEs are aimed to reduce the number of Office Actions. These concepts are familiar to those practicing at the United States Patent and Trademark Office (USPTO) and the European Patent Office (EPO). While excess claims fees are now common in these jurisdictions, there are important differences that provide additional challenges in Canada.

In the United States, there are mechanisms to manage the issue by filing additional applications such as Continuation Applications or Continuation-in-part Applications. In Canada, there are no such mechanisms, and the only option is to file a divisional application. However, the filing of multiple applications raises the issue of the judicially derived concept of double patenting (“same invention” or “obvious-type”), which is intended to prevent more than one patent being issued with claims protecting the same subject matter. United States patent law allows applicants to file terminal disclaimers (where the term of a second patent ends at the same date as a first patent directed to a similar invention) to address double patenting objections. However, Canada does not allow terminal disclaimers. If the claims of a divisional application are not patentably distinct from the issued parent, the claims may not be allowable and the applicant may then have no recourse available to obtain those claims.


One way to resolve the double patenting issue is to include claims for any and all possible embodiments in the parent application, thereby eliciting a stance from the Examiner regarding unity of invention. If the Examiner raises a unity objection, the Applicant is then free to file a divisional application free from any possible double patenting allegations. However, this option may now require payment of excess claim fees. Furthermore, this strategy may prolong examination because an office action may be issued simply to raise a unity of invention objection before substantive examination of the claims takes place, increasing the chance that an RCE will be required to complete prosecution before the application is allowed.

One strategy is to include independent claims directed to all desired embodiments of the invention in the original application, while limiting the overall number of claims to 20 or fewer, thus eliminating excess claim fees. This will force the Examiner to establish a stance on unity. If a unity objection is raised, any non-elected claims may become the subject of a divisional application without the risk of a double patenting objection. However, in the case where a unity of invention objection is not raised and the application proceeds directly to allowance, the applicant is left with the possibility of having to withdraw the Notice of Allowance and file an RCE to add important dependent claims that were left out of the original application.

A possible solution is to use alternative/optional language. For example, a single dependent claim could be drafted by combining features of two or more dependent claims using language such as “or”, “and/or”, “optionally”, “preferably”, “in particular” or the like. Since such alternative/optional language is generally not permitted in Canada the Patent Office will almost certainly object. However, the goal is not to get the claims allowed but to keep the claim number as low as possible, while at the same time having the maximum amount of subject matter considered by the examiner. It also guarantees at least one Office Action.

Unfortunately, there are many instances where Canadian Examiners do not raise any objections towards a particular claim in a first Office Action, only to reject it at a later time. Since Applicants will now have to pay for RCEs to extend prosecution beyond the first two office actions, the hope is that Examiner training will improve, and these problems will be alleviated.

In conclusion, with the new Canadian Patent Rules there are new issues to consider, and no two patent applications are alike. Devising claim reduction strategies in Canada will require a delicate balance between excess claim fees, RCE costs, and the desired scope of protection for the invention. It will be up to each Applicant to determine how much time, and money, they are willing to invest to protect different aspects of an invention.

Of course, that is where having a knowledgeable patent agent to address these issues can provide great benefit. With over 45 years of experience, Moffat & Co. ensures that all of our Canadian and international clients receive efficient and effective intellectual property protection and guidance, in Canada and throughout the world.