Merits and Requirements of Divisional Applications

2021.11.04
Aki Ryuka
Patent Attorney, Japan


1. Why to file a divisional application?

Protecting Different Aspects
If the applicant wishes to protect different features of the invention in the future, it is advisable to file a divisional application.

Helping Litigation and Licensing
In the infringement litigation, the accused infringer always alleges non-infringement by proving how the structure of their products is different from the patent. Here, if the patent owner has a divisional application, the owner can amend the claims to cover the infringer’s “proved” structure. This makes it hard to prove the difference and weakens the infringer’s position, thereby elevating the patent owner position during patent licensing or settlement negotiations.

However, the advantages are available only when the claims can be amended, namely during the examination period of about one to two years. For keeping the amendment opportunities longer, the applicant needs to file a chain of divisional applications.

Our Suggestions
Balancing the fees and costs with the above benefits, we suggest filing divisional applications when the value of the patent or the risk of infringement is high.

2. When to file a divisional application?



3. Filing a divisional application with new claims?
If a feature is deleted when a divisional application is filed, the deleted feature cannot be reinstalled. Accordingly, we suggest filing a divisional application that is the same as the parent application and introducing new claims by a preliminary amendment or translation for maximizing the scope of future amendments.

4. Avoiding the first and final OA.
If the parent application receives an OA before the examination is requested for the divisional application, the reasons of the parent OA must be cured in the divisional application beforehand. Otherwise, the first OA to the divisional application will be made final, and the applicant can only limit the elements that already exist in the claims.

If you need any other information, feel free to contact us.


This information is provided for general informational purposes only, and is not intended as legal advice. Because every case is unique, readers should not take any action, or refrain from acting based on this information without first consulting their own attorneys. The law is constantly developing, and this information may not be updated with each and every development. The mere presentation of this information does not create an attorney-client relationship with RYUKA IP Law Firm. RYUKA IP Law Firm specifically and wholly disclaims liability for this information.