Divisional Practice in Canada

Time Periods for filing a Divisional Application

In Canada, a divisional application must be filed before issuance of an original application (parent application).   If a parent application becomes abandoned, a divisional application can be filed before the expiration of the time limit for reinstatement of the parent.  Divisional applications can be filed for any reason (often referred to as “voluntary” divisional applications) or in response to a lack of unity rejection.  Cascading divisionals (meaning a divisional application filed from another divisional application) are permitted.

Requirements for Filing a Divisional Application

When filing a divisional application, a copy of the specification, abstract and drawings from the parent application must be filed.  A set of claims (either the original claims from the parent application or a new claim set) must also be included.  In addition, the following are also required:

1.  A written statement that a patent is being sought;

2.  Payment of all the necessary filing fees, as well as the annuity fees accrued since the filing date of the parent application;

3.  The name of the Applicant; and

4.  The address of the Applicant’s agent.

Claims of a Divisional Application

A divisional application may be filed with the claims as originally filed in the parent or PCT application.  However, the claims of a divisional application filed with the same claims of a parent or PCT application will need to be amended at some point during prosecution to ensure that neither the parent or divisional application claim the exact same subject matter and are patentably distinct (meaning novel and nonobvious) from one another. 

Double Patenting

In Canada, much like the United States (U.S.), there is a prohibition against double patenting.  This prohibition comprises 2 branches:

1.  A “same invention” or “coterminousness” branch; and

2.  An “obviousness” branch.

The “same invention” or “coterminousness” branch is similar to statutory double patenting in the U.S., where claims of a pending application and an issued patent cannot have the same exact (identical) scope.  A rejection based on the “same invention” or “coterminousness” generally is not fatal and can be overcome by amending the rejected claims so as not to have the identical scope as claims of the issued patent or copending application. 

The “obviousness” branch is similar to “obviousness-type” double patenting in the U.S. but can be much more problematic in Canada.  Under this branch, the claims of a pending application (such as a divisional application) must be patentably distinct (meaning novel and nonobvious) over the claims of an issued patent or copending application.  In the U.S., in most instances, an obviousness-type double patenting rejection can be obviated by the filing of a terminal disclaimer.  However, Canadian law does not provide for the procedural equivalent of a terminal disclaimer.

Nonetheless, according to Canadian case law, if the claims being pursued in a divisional application were filed in response to a lack of unity rejection in a parent application, then the claims of the divisional application are immune from a double patenting attack based on the parent application (See, Consolboard Inc. v. MacMillan Bloedel (Saskatchewan) Ltd., [1981] 1 S.C.R. 504).

Therefore, an Applicant filing a voluntary divisional in Canada must be very careful to make sure that the claims of its divisional application:  (1) do not claim the same invention as the parent application; and (2) are patentably distinct over the claims of the parent application.

Similar to the U.S., an issued patent can be invalidated for double patenting in Canada.  However, in contrast to the U.S., no procedural remedy exists in Canada to cure a deficiency under either branch once a patent has issued.

As a matter of practice, the best option in Canada is to file all claims of interest in the parent application, and allow the Examiner to make an assessment of whether there is more than one invention so that a formal requirement for division is on record before a divisional application is filed, even if the parent application is already allowed.  In effect, voluntarily filed divisional applications should be avoided in Canada where possible.

Examination of Divisional Applications

A divisional application is treated as a separate application and is accorded a separate application number, requires separate fees, requires a separate request for examination, will be prosecuted separately from the parent application, and will result in an independent patent from the parent application.  The fees for a divisional application are the same as for any parent application.  The term of patent for a divisional application is twenty years from the filing date of the very first parent application. 

When prosecuting a divisional application, care should be taken to avoid amendments that might cause the claims to depart significantly from what the Examiner originally considered to be a separate invention.  Therefore, to ensure validity of both parent and the divisional patents, it is advisable to refer back to the original requirement to divide a set of claims so that new issues of double patenting are not created inadvertently.

This is Part 7 of a nine-part series examining divisional practice in the BRIC as well as several non-BRIC countries.  To view Part 1 (Divisional Practice in Mexico), click here.  To view Part 2 (Divisional Practice in Brazil), click here.  To view Part 3 (Divisional Practice in the United States), click here.  To view Part 4 (Divisional Practice in India), click here.  To view Part 5 (Divisional Practice in Russia), click here.  To view Part 6 (Divisional Practice in China), click here.

Trevor Newton of Gowlings also contributed to this article.

To view Part 1 (Divisional Practice in Mexico), click here. 

To view Part 2 (Divisional Practice in Brazil), click here. 

To view Part 3 (Divisional Practice in the United States), click here. 

To view Part 4 (Divisional Practice in India), click here. 

To view Part 5 (Divisional Practice in Russia), click here.

To view Part 6 (Divisional Practice in China), click here.