South Korea allows a one-year grace period for pre-filing disclosures by inventors or applicants so that these disclosures are not regarded as prejudicial prior art in terms of novelty and inventiveness (Article 30 of the Patent Act).


In Korea, this grace period system has evolved over time. The law opened the door to all types of disclosures except for patent publications in Korea or foreign countries (as of March 3, 2006), extended the duration from six months to one year (as of March 15, 2012), and added procedural flexibility by allowing later claiming of the grace period such that it does not have to be made at the time of patent filing (as of July 29, 2015).

Before all these changes, some portion of patent applications had to be rejected when they failed to comply with the procedural requirements, which appear quite stringent from the present perspective.

The Korean Supreme Court took another step forward in 2022. Without changing the law itself but through the interpretation thereof, it was declared that a divisional application can claim the benefit of the grace period (that the parent application could have claimed) even if the parent application had not claimed the same benefit (Supreme Court Decision 2020Hu11479, August 31, 2022).

Facts and case history

In this case, the applicant did not claim the grace period for the prior disclosure (his master’s thesis published around August 2014) at the time of filing the parent application on December 23, 2014. The Examiner at the Korean Intellectual Property Office (KIPO) rejected the parent application for lacking novelty and inventiveness over the applicant’s thesis.

Since the parent application was filed before the enforcement date (July 29, 2015) of the amended provision of the Patent Act, which allows for a chance to amend defects in claiming the grace period during the prosecution, there was no option to amend the procedural defects in response to the Examiner’s rejection.

Given the situation, the applicant filed a divisional application claiming the grace period within the allowed timeframe, and then withdrew the parent application. However, KIPO did not acknowledge the claimed grace period, and the divisional application was ultimately rejected for lacking novelty and inventiveness. Despite the applicant’s appeal, the Intellectual Property Trial and Appeal Board affirmed the Examiner’s rejection, as did the Patent Court.

Supreme Court’s decision

However, the Supreme Court expressed a different view on the matter, and concluded that even though the grace period had not been claimed in the parent application, in view of the purpose of the relevant provisions, it is reasonable to interpret that the divisional application can enjoy the benefit of the grace period based on ‘its’ (i.e., the divisional application’s) filing date if:

The procedures for claiming the grace period had been duly observed in the divisional application; and

The parent application had been filed within 12 months from the prior disclosure date.

In this decision, Hanol IP & Law believes that the Supreme Court properly recognized the essence of the divisional system of Korea. In this jurisdiction, the applicant can file divisional applications for any subject matter that was included in the original application, even if the examiner has not issued a rejection for lack of unity of invention.

If, in the parent application, the applicant was not interested in pursuing the subject matter that had been pre-disclosed by the applicant, there would have been no need to claim the grace period. But if the applicant were to change their mind later to have patents directed to those subject matters, it was probably not the lawmakers’ intention to block the patenting of such subject matters only because the applicant did not pursue them from the beginning, by prohibiting claiming of the benefit at the later divisional stage.

Final remarks

Fortunately, under the present law, there are ample opportunities to amend defects in claiming the grace period during the prosecution, even if the claiming procedure had been mistakenly missed at the time of filing. However, if the Patent Cooperation Treaty or Korean filing date is before July 29, 2015, this option is not available. Instead, filing a divisional application can be an alternative in view of this recent Supreme Court decision.

This case is meaningful because it shows that even if the old law applies, a missed claiming procedure can be remedied by filing a divisional application claiming the grace period, as long as the original application was filed within the one-year grace period.


Our thanks to Min SON, Ph.D., Patent Attorney for this article which was first published in the HANOL 2022/23 newsletter. 

Image for illustrative purposes only, shows appointment of new judges to Korean Supreme Court 2023 (copyright KSC)

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