March 23, 2023

Change to IPONZ examination practice – parent-divisional claim overlap


The Intellectual Property Office of New Zealand recently implemented changes to its examination practice for examining New Zealand patent applications under the Patents Act 2013. The changes relate to how IPONZ examines overlapping scope between parent and divisional applications.

Parent and Divisional Patent Applications

Patent applications sometimes describe multiple inventions. Since a patent is only permitted to protect a single invention, a second invention described in the same patent application can be protected by “dividing out” claims protecting the second invention in a divisional application. The divisional application inherits the basic properties (e.g. filing date, priority details) from the original application, which is known as the “parent”. The divisional application then provides separate legal protection for the second invention.

It is a common principle of patent law that the same applicant should not obtain multiple patents for the same invention, and the law in NZ specifically prevents this. For this reason, IPONZ carefully examines divisional applications to assess the extent of overlap with the parent applications.

IPONZ’s Previous Practice for Examining Parent-Divisional Claim Overlap

The extent to which there can be overlapping claim scope between parent and divisional applications is governed by regulation 82 of the Patents Act 2013, which requires that, in order for a parent/divisional application to be accepted, it must not include a claim for substantially the same matter as an accepted divisional/parent application.

Up until recently, IPONZ has examined this requirement in much the same way as parent-divisional claim overlap was examined under the previous New Zealand patent legislation: the Patents Act 1953. That is, IPONZ would raise an objection if the scope of one claim in a parent or divisional was wholly contained within the scope of a claim of the other parent / divisional case.

In addition, IPONZ has interpreted regulation 82 as requiring the comparison between the pending case and accepted case to be made based on the claims of the accepted case as they stood at the time they were accepted, and to disregard any changes to the claims or their status after that time.

Two IPONZ decisions issued in 2021 that relate to the issue of parent-divisional claim overlap:

Recently, IPONZ updated the section of the Examination Manual dealing with examination of parent-divisional claim overlap under regulation 82 as a result of these decisions: Regulation 82: Parent and divisional claims “for substantially the same matter”.

Meaning of “Substantially the Same” & Double Infringement Test (Oracle)

Following the Oracle decision, the requirement that a parent and divisional do not include claims for “substantially the same matter” has been clarified as meaning that the claims must not relate to subject matter that is “essentially the same”, “the same but for minor unimportant details”, and/or “not substantially different” (see paragraph [15] of the Examination Manual).

Oracle introduced the “double infringement test” as a way to assess this overlap, and this test has been adopted into IPONZ’s examination practice by its inclusion in the Examination Manual. The key points about this test are:

1. To assess overlap between a claim of a parent and a claim of the divisional, ask whether:

a. An infringement of the claim of the parent would also be an infringement of the claim of the divisional; and
b. An infringement of the claim of the divisional would also be an infringement of the claim of the parent.

2. If the answer to both questions is “yes” then there is impermissible claim overlap.

3. Crucially, the term “an infringement” in the double infringement test is taken to mean “all infringing embodiments” that fall within the scope of the claim, not just any “single infringing embodiment”. If there are infringing embodiments within the scope of one claim which are not within the scope of the other claim, this will not meet both arms of the double infringement test.

The double infringement test applies to all claims in the parent and divisional applications, including both independent and dependent claims.

The Examination Manual also provides a few examples of hypothetical claims that do and don’t fail the double infringement test.

Overlap Can be Resolved By Amending / Withdrawing Accepted Case (Ganymed)

The Ganymed decision has clarified that a parent-divisional claim overlap objection can be addressed in one of three ways:

1. Arguing with the merits of the objection;
2. Amending the claims of the pending application to remove the claim overlap; and
3. Amending the claims of the accepted case, or withdrawing the accepted case.

The change in practice introduced by the Ganymed decision is the addition of option 3 in the list above. This is now an option by which to overcome a claim overlap objection even if the claims of the pending application would have overlapped with the claims of the accepted case as they stood at the time the accepted case was accepted.

Not Limited to Parent and Immediate Divisional

The Examination Manual clarifies that, although regulation 82 refers only to parent and divisional applications, IPONZ will apply the restrictions on claim overlap under this regulation to any two applications in the same divisional family, including “grandparent”, “parent”, “sibling” and “child” applications, i.e. any two applications that are linked by a divisional chain back to the same NZ parent application. 


The effect of these changes to IPONZ’s examination practice is likely to be generally beneficial to patent applicants as the changes allow a greater amount of overlap between parent and divisional applications. Previously, claim overlap would be found wherever the scope of a claim in one application fell wholly within the scope of a claim in its parent/divisional application. Now, claim overlap will only be found where there are two claims that have substantially the same scope.

In addition, these changes align examination of parent-divisional claim overlap in New Zealand much more closely with how this is assessed in major trading partners, including Australia.

For more information please contact us or your usual James & Wells advisor.

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