Changes in Japanese Patent Law: Multiple-Multiple Dependent Claims Prohibited

By November 7, 2023 News

Recent changes in Japanese patent law have introduced significant restrictions on the drafting of patent claims. In Japan, much like in the United States and other jurisdictions (except EP), a significant modification in patent claim drafting has been implemented, which has brought an end to the practice of using “multiple-multiple dependent” claims. This change is important for patent applicants and practitioners to understand, as it affects the strategy of preparing claims in both PCT (Patent Cooperation Treaty) applications and Paris route applications in Japan.

The change in Japanese patent law pertains to the prohibition of “multiple-multiple dependent” claims, a practice that was previously allowed. Applications with an effective filing date as of April 1, 2022, international filing date for PCT applications and the Convention priority date for Paris route applications specifically, cannot include multiple-multiple dependent claims. This is a significant shift, as applications that contain such claims will be rejected solely on this ground.

In our next post, McCoy Russell will discuss what multiple-multiple dependent claims are and the impact on patent filings.