A patent’s duration is fairly standard in Japan: 20 years from the filing date. (For a PCT international application that enters the national phase in Japan, that is 20 years from the international filing date.) Sometimes, though, an applicant might not be able to work the invention right away and want to extend the expiration date of the patent. What then?

(When) can I extend my patent’s duration?

Unlike with the USPTO, the JPO does not automatically give an extension based on delays in the examination process. However, the Japanese Patent Act allows for an extension if there is a period when the patented invention cannot be worked by means of producing, using and assigning the invention of a product, due to specific regulative delays caused by other laws (Article 67 [2]). A Japanese patent attorney can request to extend the expiration date of a patent up to 5 years.

Article 67 (2) of the Patent Act giving the requirements for extending a patent’s duration is translated as follows:

Where there is a period during which the patented invention is unable to be worked because approvals prescribed by relevant Acts that are intended to ensure the safely, etc. or any other disposition designated by Cabinet Order as requiring considerable time for the proper execution of the disposition in light of the purpose, procedures, etc., of such a disposition is necessary to obtain for the working of the patented invention, the duration of the patent right may be extended, upon the filing of a request for the registration of extension of the duration, by a period not exceeding 5 years.

What if I have multiple patents for one product that I was not able to work immediately, and want an extension on each patent? Will all the patents get the same extended duration?

Each application is considered and would be extended separately. That is, if multiple patents for the same product exist, each patent may be extended, based on Article 67 (2), based on its own application date alone. As a result, each patent may end up expiring on a different date, and the part of the invention whose patent expires earlier would no longer be protected.

(The information provided on this website is for informational purposes only and is not intended as legal advice. For questions or inquiries, please contact us for more information.)


Translated Articles 67, 67-2 of “Patent Act.” Japanese Law Translation.
Japan Patent Act, original text. E-Gov. Effective May 30, 2017.