About Us
Global Law Experts Logo
Global Law Experts Logo

Find a Global Law Expert

Practice Area


Since 2010, the Global Law Experts annual awards have been celebrating excellence, innovation and performance across the legal communities from around the world.

New Rule, April 2023: Reinstatement for Patent Applications to Meet “Unintentional” Instead of “Due Care” Standards

posted 1 year ago

April 1, 2023 marks an important shift for those who might realize, with dread, that a key patent deadline in Japan has been missed. The standard for Reinstatement (Revival with a late filing) is softening from “Justifiable” to “Unintentional” Delay. We want to summarize for you this important change.


The Japanese patent examination standards up to March 31, 2023 have asked whether the applicant or agent acted with such “Due Care” that failure to file on time had a “justifiable cause.” Japan’s standard for what constituted “Due Care” was notoriously and extremely rigorous. For comparison, other major examining offices with similar standards might have a 60-95% reinstatement rate, that rate has been around 10-20% in Japan.

Therefore, the Japanese government recently passed amendments to the Patent Act to lighten the burden of proof for the applicant and improve reinstatement acceptance rates, and this goes into effect April 1, 2023.

Filings Now Reinstated for “Unintentional Delay” and Deadlines

If the applicant lives outside of Japan, procedures such as the following may be filed with a Petition for Reinstatement (Revival) and accepted late under the rubric of “Unintentionality,” when the deadline falls on or after April 1, 2023:
– Paris Convention Priority Claim*
– Japanese translation of an application initially filed in another language (like English)
– Japanese translation of international PCT application filed in a foreign language**
– Request for Examination by JPO
– Payment of Patent Fee or Patent Fee surcharge

The assumption is that the applicant failed to meet the pertinent deadline (on or after April 1, 2023) unintentionally. In this case, the applicant still needs to file the procedure with a Request for Reinstatement (回復理由書 kaifuku riyusho) within 2 months after remedy of the missed deadline becomes possible (i.e. the need and possibility is recognized) and before 1 year after the missed deadline has elapsed.[1]

Please note, there are also filings for Utility Models, Designs, and Trademarks that may be filed late under the “Unintentional Delay” rubric, as well.[1]

* Exception: a Paris Convention Priority Claim may be filed for the applicable application (patent application with Paris Convention priority claim or PCT international application) only up to within 1 year and 2 months of the Priority date.[1]

** Qualifying statement: If a PCT international patent application claiming priority includes the JPO as a Designated Office, then the window to file the Petition for Reinstatement extends to only 1 month beyond the National Phase entry deadline (or, if the deadline for Japanese translation of the PCT application is separate, 1 month from that deadline).[2]

Explaining the Situation in the Petition for Reinstatement

The Japanese patent agent needs to file a Petition for Reinstatement briefly stating (in a few lines) the reason the applicant could not file on time and the day when the applicant realized the filing was possible, as well as the fact that missing the deadline was “not intentional.”[1]

Under the stricter, pre-April 2023 standard of “Due Care” in cases of late filing, it was necessary to submit reasons and evidence that there was “justifiable cause,” with extreme burden to the applicant. However, with the present amendments, this burden of proof will likely decrease dramatically.

Reinstatement Fees

There was no official fee for recovery by Reason for Reinstatement until March 2023, but when filing a Petition for Reinstatement under the “Unintentionality standard,” 212,100 yen (about US$ 1,500) is due for the official fee.[1]


The Unintentional Delay standard sounds like a welcome change, but how much will reinstatement become easier in Japan? Only more time will tell.

If you have any questions, please contact us.

* The information provided on this website is for informational purposes only and is not intended as legal advice.
** For questions or consultation, please contact Taro Yaguchi or our firm for more information.



Japan Patent Office. “期間徒過後の救済規定に係る回復要件が「正当な理由があること」から「故意によるものでないこと」に緩和されます [Reinstatement standard for remedy of missed deadline to change from ‘justifiable cause’ to ‘unintentional delay’].” February 13, 2023. Accessed March 31, 2023.

Header image by chihiro sakai from Pixabay

Find the right Legal Expert for your business

The premier guide to leading legal professionals throughout the world

Practice Area
0 m+


who are already getting the benefits

Sign up for the latest legal briefings and news within Global Law Experts’ community, as well as a whole host of features, editorial and conference updates direct to your email inbox.

Naturally you can unsubscribe at any time.

Newsletter Sign Up

About Us

Global Law Experts is dedicated to providing exceptional legal services to clients around the world. With a vast network of highly skilled and experienced lawyers, we are committed to delivering innovative and tailored solutions to meet the diverse needs of our clients in various jurisdictions.

Contact Us

Stay Informed

Join Mailing List