NAVIGATING THE NEW CANADIAN PATENT RULES.

Managing multiple inventions while limiting costs and mitigating double patenting risks
Laurence Bourget-Merle1, Isabelle Girard2 and Julien Fleurance3
ROBIC, LLP
1 Ph.D., Chemist and Patent Agent, 2 Physicist, Partner and Patent Agent, 3 Partner and Patent Agent
The new Canadian Patent Rules that came into force on October 3, 2022, introduced new fees and procedures which have the potential of substantially increasing the costs of patent prosecution in Canada. Under the new Patent Rules, excess claim fees of $100 CAD per claim beyond the 20th must be paid at two instances during prosecution of the application: at the time of filing the Request for examination and at the time of paying the final fee. The amount due at the time of filing the Request for examination is based on the current number of claims contained in the application. The amount due at the time of payment of the final fee is based on the difference between (i) the fees associated with the maximum number of claims reached during prosecution and (ii) the excess claim fees, if any, already paid at the time of payment of the Request for examination. The new Patent Rules also introduced the required filing of a Request for Continued Examination (RCE) after the first three examination reports and after every two subsequent examination reports. The filing of an RCE is also required for entering any amendment after allowance under the new rules. Each RCE requires an accompanying fee of $816 CAD.
These changes apply to all patent applications for which the Request for examination is filed on or after October 3, 2022. Among other issues, they will considerably impact the way Applicants must manage patent applications disclosing multiple inventions, specifically in view of the stringent double patenting doctrine in Canada. While most jurisdictions, including the United States and Europe, allow the filing of voluntary divisional or continuation applications to pursue additional inventions, filing voluntary divisional applications in Canada is generally not recommended, due to potential invalidity concerns on the grounds of double patenting. Rather, divisional applications should be filed in response to a lack of unity of invention rejection identifying multiple invention groups, providing a path to immunize the resulting patents against double patenting invalidity.
A common practice in Canada is to file large claim sets including all of the claims considered for a given patent family, with the express purpose of obtaining the Examiner’s assessment of unity of invention. Such a strategy can, however, be quite onerous for patent applications subject to the excess claim fees provisions of the new Patent Rules. This article outlines some practice tips that can mitigate the impact of the changes to the Canadian Patent Rules with respect to patent applications disclosing multiple inventions. Examples are also provided below to illustrate these practice tips.
Making Good Use of Voluntary Amendment
In Canada, voluntary amendments can be made at any time after a direct filing of a patent application or after the national phase entry of a PCT application. Any amendment must be supported by the application as originally filed, i.e., “reasonably inferred” from the original text and drawings. Under the new Patent Rules, the filing of the Request for examination will become a key strategic moment to consider the filing of a voluntary amendment, if only to reduce the claim count and avoid or minimize excess claim fees. The opportunity can also be taken to optimize the claims in view of Canadian practice. It is to be noted that claims with multiple dependencies are permitted in Canada and each multi-dependent claim will count as a single claim for the purpose of calculating excess claim fees. The same is true for claims that define subject matter in the alternative. In addition, amendments made during the pendency of a patent application may impact the reasonable compensation to the patentee for infringement acts committed between the application publication date and issuance date.
A voluntary amendment can be filed prior to or at the time of filing the Request for examination and can also be used to introduce claims to any additional invention(s) disclosed in the application and not yet claimed. This is likely to trigger a rejection for lack of unity of invention and give the Applicant the chance to safely file a divisional application, in contrast to filing a voluntary divisional application. To do so without paying undue amounts in excess claim fees, one strategy that Applicants can consider is to file a voluntary amendment to introduce claims directed to the various disclosed inventive concepts, using broadest (independent) claims and key dependent claims with multiple dependencies while keeping the number of claims to a total of 20, as far as possible. It can also be possible to combine dependent claims in alternative format while making sure that commercially important embodiments are claimed by themselves to limit their exposure to invalidity.
Since voluntary amendments can be filed at any time during examination, it could also be possible to introduce claims directed to another inventive concept to trigger a lack of unity rejection, during examination such as when responding to an examination report for instance. However, this timing could increase the prosecution costs since the lack of unity rejection would count for an additional examination report potentially resulting in the necessity to file an RCE. Therefore, it would be preferable to introduce claims to any additional inventive concept(s) early in the application pendency and before examination starts.
However, Applicants noticing, after the receipt of a notice of allowance, that the allowed claims do not cover all the inventive concepts they want to protect, will still have the opportunity to amend the claims after allowance under the new rules. More particularly, a voluntary amendment can be filed with an RCE, after allowance, to introduce independent claims covering each of the additional inventive concepts to be protected, to trigger a rejection for lack of unity of invention, and then be able to safely file one or more divisional applications on the additional concepts.
Examples illustrating different scenarios of managing multiple inventions under the new Canadian Patent Rules will now be provided.
Example of Managing Multiple Inventions Before Requesting Examination
Figure 1 shows the prosecution timeline according to a first scenario where an application discloses more than one inventive concept and was filed with more than 20 claims.
Figure 1

If the claim set as filed includes claims directed to all the inventive concepts to be covered, let’s say concepts A and B, a voluntary amendment is filed before requesting examination, to reduce the total number of claims to 20, to optionally introduce dependent claims to key embodiments and/or to add multiple dependencies. If the original claim set only includes claims to concept A but concept B is to be protected, an independent claim to concept B should be introduced by way of a voluntary amendment before requesting examination. Dependent claims to key embodiments of concept B and/or multiple dependencies can also be introduced at the same time. When filing the Request for examination, within four years from the filing date, no excess claim fees need to be paid since the total number of pending claims at this stage is 20.
A first examination report issues rejecting the application for lack of unity, identifying two groups of inventions corresponding to concepts A and B. Applicant then responds to the report electing concept A (e.g., claim 1 and claims depending thereon) within four months of the report date. This implies removing any claims to concept B. Since we can have 20 claims at any time during pendency without having to pay excess claim fees, additional dependent claims to concept A, up to a maximum of 20 claims, can be added when responding to the lack of unity rejection. In the scenario shown in Figure 1, a second examination report issues raising substantive rejections on claims to concept A, such as lack of novelty, obviousness and/or lack of utility, and potential clarity objections. A response is filed to this second report while keeping the number of claims to 20 in total. At this stage, if the examiner determines that the application complies with the Patent Act and Rules, a notice of allowance will issue. However, in the scenario shown in Figure 1, the examiner determines after revising the response to the second report that the application is still not compliant, and a third examination report is sent to the Applicant with an RCE notice. For the application to be further examined, the Applicant must file the response to the third report with the payment of the statutory RCE fee. The application is then returned to the examiner for further review. If the examiner finds the application to be compliant, a notice of allowance issues and the Applicant has four months to pay the final fee. In the present scenario, the number of claims was kept to 20 in total throughout the patent application pendency, and, therefore, no excess claim fee is payable with the final fee. Even if divisional applications can be filed until the day before the patent from the parent application is granted, it is strongly recommended filing any divisional application before paying the final fee. Hence, as shown in Figure 1, a divisional application to concept B should be filed as soon as possible after receiving the notice of allowance and preferably before paying the final fee. In the divisional application on concept B, the applicant can include the associated claims removed from the parent application, in response to the lack of unity rejection, and add any additional dependent claims of interest until reaching 20 claims in total.
Example of Managing Multiple Inventions After Allowance
Figure 2 shows the prosecution timeline according to another scenario where an application disclosing more than one inventive concept is filed, examined, and allowed with claims to only one of the concepts, but the Applicant wants to obtain patent protection for at least another inventive concept. Such a scenario is typical of cases where a continuation strategy in the United States is to be mirrored in Canada. Since filing a voluntary divisional application is very risky in Canada due to double patenting, steps need to be taken after allowance to reduce the risks.
Figure 2

In this scenario, the application as filed includes 20 claims covering a single inventive concept A. Since the application contains 20 claims, no excess claim fee is payable at the time of requesting examination. A first examination report issues raising substantive rejections and/or objections for lack of clarity. Applicant files a response to the first report within the prescribed four-month period, amending the application to overcome the issues raised by the examiner while keeping the claim number to a total of 20. The claims remain directed to concept A at this stage. The examiner reviews the application as amended and finds that it still does not comply with the Patent Act and Rules and issues a second examination report. A response is then filed to the second report to address any rejections and/or objections raised in the second report. At this stage, the 20 pending claims are still directed to concept A only. After a review of the response to the second report, the examiner determines that the application complies with Canadian patent practice and a notice of allowance issues. Upon reviewing the case after allowance, the Applicant notices that a second inventive concept B disclosed in the patent application should also be protected. In view of the double patenting risk, the filing of voluntary divisional covering concept B is not recommended and the preferred way to pursue claims to concept B is to file a voluntary amendment after allowance, to then trigger a lack of unity rejection and safely file the divisional application to concept B. Under the new Patent Rules, such amendment after allowance is only possible if accompanied with an RCE and the payment of the statutory RCE fee. The voluntary amendment with an RCE, in this scenario, must be filed before the expiration of the four-month period from the date of the notice of allowance. In the voluntary amendment, some of the dependent claims on concept A are replaced with one independent claim and key dependent claims on concept B, to maintain the total number of claims to 20 to avoid excess claim fees. The application is then returned to the examiner for further review. Since the claims are now covering two different inventive concepts, the examiner issues a first post-allowance examination report raising a rejection for lack of unity, identifying one claim group to concept A and another claim group to concept B. Applicant then files a response to the report electing concept A, and removing claims to concept B. When filing the response, dependent claims to concept A, which were removed at the time of filing the voluntary amendment after allowance, can be reintroduced. Hence, the total number of claims at this stage is still 20. After filing the response to the post-allowance examination report, a notice of allowance issues if the examiner determines that the application is compliant. Then, as explained above for the first scenario, the Applicant has four months to pay the final fee and should file the divisional application on concept B before paying the final fee. In the divisional application on concept B, the Applicant can include the claims removed from the parent application, in response to the lack of unity rejection, and add any additional dependent claims of interest until reaching 20 claims in total.
Conclusion
Canadian divisional practice is less flexible than in most other jurisdictions, including the United States and Europe, and the filing of voluntary divisional applications is generally not recommended due to potential double patenting issues. Rather, divisional applications should be filed in response to a unity of invention rejection. As a result, Applicants are advised to use a claim consolidation approach in which all claims of potential interest are submitted for consideration by the examiner, who will then either allow the claims to proceed in the same application or issue a unity rejection allowing the safe filing of divisional applications. Because this claim consolidation approach typically involves the filing of large claim sets, its implementation has become more challenging with the introduction of excess claim fees under the new Patent Rules. Thus, if Applicants seek to cover multiple inventions disclosed in a patent application or pursue independent claims of varying scope or format that may not be directed to distinct inventions (e.g., corresponding to U.S. Continuation claims), Canadian patent agents can provide guidance on potential strategies to optimize claim scope in a cost-effective manner. Examples of such strategies have been presented above.