This month an update to Japanese patent practice took effect.  For applications filed after 1 April 2022, so called “multi-multi claims” are no longer allowed.  This includes applications which have entered Japan via a PCT application, where the filing date of the PCT application is also considered the filing date of the resulting Japanese application.  As requests for examination of Japanese patents occurs three years after filing, applications are now being considered under the new regime.

Multi-multi claims are claims which are dependent on multiple claims which are themselves dependent on multiple claims.  These types of claims can be more time consuming to examine as each combination of claims features must be considered.  The Japanese Patent Office is not alone in seeking to reduce the use of these types of claims.  The USPTO also penalises their use, with each claim combination being counted as a separate claim when calculating any excess claims fees.

The consequences of maintaining multi-multi claims during examination before the JPO are however more severe.  Any offending claims will be rejected without consideration of the other patentability requirements.  The claims will continue to suffer consequences in later examination, if in response to an objection in the first office action the claims are amended, any objections on other patentability grounds will result in a Final office action, limiting the applicant’s scope for overcoming the objection.

It is therefore highly advisable that Japanese applications are put in good order prior to examination.  Where multi-multi claims are removed before examination, the consequences are avoided.

These changes are a timely reminder that filing patent applications overseas requires careful consideration.  For more information, or advice regarding overseas patent applications, please contact one of our attorneys.