What is the grace period under the disclosure exception in Korea?

Sangwook Je, Partner · Published 30 October 2026

Last verified 9 October 2026

Time limits at a glance

As of October 2026.

The Korean application must be filed within 12 months from the disclosure

Article 30(1) of the Patent Act requires the patent application to be filed within 12 months from the date the invention was disclosed. [1] If the application is filed within that period, the disclosure is not treated as prior art when novelty and inventive step are assessed. [1]

Two kinds of disclosure are covered. One is a disclosure made by the person with the right to obtain a patent. The other is a disclosure made against the intention of that person. [1] The form of the disclosure is not limited, and the disclosure can be in Korea or abroad. [1][6]

However, laying-open of an application and publication of registration are excluded from disclosures made by that person. The proviso to Art. 30(1), subparagraph 1 excludes laying-open of an application and publication of registration in Korea or abroad. [1] If another application filed earlier by the same applicant has been published in a gazette, the disclosure exception cannot remove it. [6]

The first day of the 12 months is not counted (Patent Act, Art. 14, subparagraph 1). [1] A period set in months ends on the day before the day in the last month that corresponds to the day on which the period started to run (Art. 14, subparagraph 3). [1] If the last day is a public holiday, Workers’ Day (노동절) or a Saturday, the period ends on the next day (Art. 14, subparagraph 4). [1] If the exact disclosure date is not known, the period is counted from the first day of the month or year that is known. [6]

The invention in the application does not have to be the same as the disclosed invention. The Supreme Court of Korea held that the disclosed invention does not necessarily have to be identical to the invention in the application (Supreme Court Decision 2023Hu10712 Decided May 29, 2025). [12] The reason is that differences can arise from research and development or improvement after the disclosure. [12]

The disclosure exception does not move the filing date back. [6] If a third party discloses the same invention between the disclosure and the filing, the application is rejected. [6] The only exception is where the third party’s disclosure is clearly a disclosure of an invention learned from the applicant’s disclosure. [6]

The 12 months are counted to the Korean filing date, not the priority date

Even if a priority claim under the Treaty is made, the Korean application must be filed within 12 months from the disclosure date. The Patent Examination Guidelines (특허·실용신안 심사기준) of the Ministry of Intellectual Property (지식재산처, MOIP) state this. [6] Article 54(1) of the Patent Act treats the foreign filing date as the Korean filing date only when Article 29 and Article 36 are applied. [1] Article 30 is not listed in that provision.

A PCT international application is different. An international application designating Korea is deemed a patent application filed on its international filing date (Patent Act, Art. 199(1)). [1] The 12 months of Art. 30(1) are therefore counted to the international filing date. [1] They are not counted to the date of entry into the Korean national phase or to the priority date.

For domestic priority, the earlier application is the reference. Article 55(3) of the Patent Act deems the later-filed application to have been filed when the earlier application was filed, for the purpose of Art. 30(1). [1] If the earlier application was filed within 12 months from the disclosure date, the later-filed application can be filed after the 12 months. [6]

This effect extends only to inventions described in the original specification or drawings of the earlier application. [1][6] For an invention newly added in the later-filed application, the filing date of the later-filed application must be within 12 months from the disclosure date. [6] The disclosure exception claim must also be stated in the written patent application of the later-filed application, and the supporting documents must be filed. [6] If the content is the same as the supporting documents filed for the earlier application, the applicant can invoke those documents. [4][6]

If the applicant disclosed the invention, state the claim in the written patent application and prove it within 30 days

Where the applicant disclosed the invention, the written patent application must state that the applicant claims the disclosure exception (Patent Act, Art. 30(2)). [1] The supporting documents are filed within 30 days from the filing date. [1] The form is the Submission of Documents, Form 13 of the Enforcement Rules of the Patent Act (특허법 시행규칙). [4] When the supporting documents are filed together with the application, a statement in the written patent application that the supporting documents are submitted can replace the Submission of Documents form. [4]

The examiner checks four points in the supporting documents: the disclosure date, the person who made the disclosure, the form of the disclosure and the content of the disclosed invention. [6] If the person who made the disclosure is different from the applicant or the inventor, the applicant must prove that the right had been succeeded to at the time of the disclosure. [6]

A disclosure made by a third party at the request of the applicant is also treated as a disclosure made by the applicant. [6] Examples are an article by a news organisation that received a press release, and a paper that cites the invention with permission. [6]

For a disclosure made against the intention of the person with the right to obtain a patent, the written patent application does not need to state the disclosure exception claim. [6] However, the application must still be filed within 12 months. [6] The applicant must prove that the invention was leaked or misappropriated against the applicant’s intention. [6]

If this was missed, supplementation is possible on payment of a fee

Even if the disclosure exception claim was not stated at filing, or the supporting documents were not filed, supplementation is possible (Patent Act, Art. 30(3)). [1] There are two periods for supplementation.

• The period in which an amendment can be filed under Art. 47(1) [1]
• 3 months from the date on which the certified copy of the decision to grant is served. If the date when the applicant intends to have the grant of the patent registered is earlier, the period ends on that date [1]

An amendment can be filed before the certified copy of the decision to grant is served. [1] After a notice of grounds for rejection has been received, an amendment can be filed only within the period for submission of a written argument and when re-examination is requested (proviso to Art. 47(1)). [1]

The same 3 months apply where the applicant receives the certified copy of a trial decision that revokes a decision of rejection (decision to reject a patent application) and is a trial decision made to register a patent (Art. 30(3), subparagraph 2). [1]

The supplementary fee is KRW 18,000 for an electronic application and KRW 20,000 for a paper-based application, for each supplementation (Regulation on the Collection of Patent Fees, etc. (특허료 등의 징수규칙), “Fee Regulation”, Art. 2(1), subparagraph 6-2). [5] The disclosure exception claim is stated in a written amendment in Form 9. [4] The supporting documents are attached to the Submission of Documents, Form 13. [4]

Supplementation does not extend the 12 months. What Art. 30(3) allows to be filed later is the document stating the disclosure exception claim and the supporting documents of paragraph (2). [1] The Examination Guidelines also state that a disclosure exception claim that does not meet the time requirement has a defect that cannot be cured. [6]

With several disclosures, a claim for the first disclosure can extend to the others

Where the invention was disclosed several times within the 12 months and only the first disclosure was claimed, the effect can extend to the other disclosures. The other disclosures must be within the scope in which identity with the first disclosure is recognised (Supreme Court Decision 2023Hu10712). [12] The Examination Guidelines state the same. [6]

A disclosure for which identity is not recognised must be claimed separately. [6] The Examination Guidelines give the example of an invention exhibited at a trade fair and separately sold on the market. The exhibition and the sale are each claimed, and supporting documents are filed for each. [6] If the sale is recognised as inseparably linked to the exhibition, the supporting documents for the sale can be omitted. [6]

Divisional applications and the PCT national phase have their own time limits

For a divisional application, the procedure is taken by reference to the time when the divisional application is filed. This is because Art. 52(2), subparagraph 2 of the Patent Act deems the divisional application to have been filed when it was actually filed, for the purpose of Art. 30(2). [1] The disclosure exception claim is stated in the written patent application of the divisional application, and the supporting documents are filed within 30 days from the date of the divisional application. [1][7]

The disclosure exception can be claimed in a divisional application even if it was not claimed in the original application (parent application). The Supreme Court held that the effect can be recognised if the original application was filed within 12 months from the disclosure date (Supreme Court Decision 2020Hu11479 Decided August 31, 2022). [7]

The same rule exists for a separational application (splitting-off) and a converted application (Patent Act, Art. 52-2(2) and Art. 53(2), subparagraph 2). [1]

For a PCT national phase application, the document stating the disclosure exception claim and the supporting documents can be filed within 30 days after the reference date (Patent Act, Art. 200; Enforcement Rules, Art. 111). [1][4] It does not matter if the disclosure exception procedure was not taken on the international filing date. [6]

The reference date is the day on which the period for submitting domestic documents ends. The period for submitting domestic documents is 2 years and 7 months from the priority date (Patent Act, Art. 201(1)). [1] If an extension of the period for filing the Korean translation was requested, the reference date is the day on which the extended period ends (Art. 201(3) and (5)). [1][6] If examination was requested within that period, the date of the request for examination is the reference date (Art. 201(5)). [1]

If the request form of the international application contains a declaration as to exceptions to lack of novelty, the disclosure exception claim is treated as stated. [6] Even then, the supporting documents must be filed within 30 days after the reference date. [6]

The 12 months date from 2012 and are unchanged in the 2027 amendment

The grace period changed from 6 months to 12 months on 15 March 2012. [2]

Articles 30, 200 and 201 are the same in the amended Patent Act (Act No. 21955) that enters into force on 16 March 2027. [3]

Example

Assume that the inventor presented the invention at a conference on 15 April 2026 and filed a US provisional application on 6 May 2026. The last day of the grace period is 15 April 2027 (Patent Act, Art. 14, subparagraphs 1 and 3). [1]

The PCT application in the third case is within the priority period of the US provisional application. Even so, in Korea more than 12 months have passed since the presentation date.

Assume that the PCT application in the second case claims priority from the US provisional application. If the period for filing the Korean translation is not extended and examination is not requested early, the reference date is 6 December 2028. The last day for the document stating the disclosure exception claim and the supporting documents is 5 January 2029.

How Korea differs

The US provision counts the 1 year back from the effective filing date (35 U.S.C. 102(b)(1)). [8] The effective filing date includes the filing date of the earliest application on which priority is based (35 U.S.C. 100(i)(1)(B)). [8] Korea counts to the Korean filing date, not to the priority date. A schedule set by the US rule can miss the period in Korea.

Article 30 of the Japanese Patent Act sets a period of 1 year, and the procedure is similar to the Korean procedure. A document is filed at the same time as the application, and a certificate is filed within 30 days. [10] The Japanese provision allows the certificate to be filed later only where the 30 days were missed for a reason beyond the applicant’s control. [10] Article 30(3) of the Korean Patent Act has no requirement as to the reason. Payment of the supplementary fee is enough. [1]

Article 55 of the European Patent Convention recognises only evident abuse and display at an officially recognised international exhibition. The period is 6 months. [9] A conference presentation or a product release made by the applicant is not in that provision.

Article 24 of the Patent Law of China sets out only four cases within 6 months before the filing date. Two are a first disclosure for the public interest in a national emergency, and a first exhibition at an international exhibition sponsored or recognised by the Chinese government. The other two are a first publication at a prescribed academic or technical conference, and a leak without the consent of the applicant. [11]

Article 54(2) of the European Patent Convention treats everything made available to the public before the filing date as prior art. [9] Article 22 of the Patent Law of China also defines prior art as technology known to the public in China or abroad before the filing date. [11] A disclosure that benefits from the disclosure exception in Korea remains prior art in both places unless it falls under Article 55 or Article 24. [9][11]

What applicants should do

In general, we suggest the following.

• Make it the rule to file before disclosing. The disclosure exception does not protect against a third party’s disclosure between the disclosure and the filing.
• If the invention has already been disclosed, find the earliest disclosure date and set the day 12 months from that date as the deadline for the Korean filing.
• Set the date of the direct Korean application or the PCT application by the 12 months from the disclosure date, not by the end of the priority period.
• Collect materials that show the disclosure date, the person who made the disclosure, the form of the disclosure and the content of the disclosure, right after the disclosure.
• If there were several disclosures and the content changed, state the disclosure exception claim for each disclosure and prepare supporting documents for each.
• If filings in Europe or China are also planned, make a separate schedule that does not rely on the disclosure exception.

Please confirm the time limits of an individual case with your agent.

FAQ

Is the grace period in Korea 6 months or 12 months?

It is 12 months (Patent Act, Art. 30(1)). [1] The period changed from 6 months to 12 months on 15 March 2012. [2]

If a US application is filed first and priority is claimed, are the 12 months counted to the priority date?

No. Even if a priority claim under the Treaty is made, the Korean application must be filed within 12 months from the disclosure date. [6] For a PCT application, the international filing date is the Korean filing date (Patent Act, Art. 199(1)). [1]

The disclosure exception claim was not stated at filing. Can this be fixed?

Yes, by supplementation (Patent Act, Art. 30(3)). [1] The supplementation is made, with the supplementary fee, within the period in which an amendment can be filed or within 3 months from service of the certified copy of the decision to grant. [1][5] If the date when the applicant intends to have the grant of the patent registered is earlier, the period ends on that date. [1]

Can the disclosure exception cover the laying-open of the applicant’s own US application?

No. The proviso to Art. 30(1), subparagraph 1 excludes laying-open of an application and publication of registration in Korea or abroad. [1]

Can a disclosure exception that was not claimed in the original application be claimed in a divisional application?

Yes. The original application must have been filed within 12 months from the disclosure date (Supreme Court Decision 2020Hu11479). [7] The disclosure exception claim is stated in the written patent application of the divisional application, and the supporting documents are filed within 30 days from the date of the divisional application. [1]

How DEFINE IP Law Firm handles this

DEFINE IP Law Firm checks the disclosure history of the invention at the first step of preparing a Korean application. If there was a disclosure, we manage the day 12 months from the earliest disclosure date as the filing deadline. We calculate the priority period and the grace period of the disclosure exception separately. For questions about the disclosure exception for Korean applications, please write to contact@defineip.kr.

Sources

1. Patent Act (특허법), Act No. 21134, in force from 11 November 2025. Articles 14, 29, 30, 47, 52, 52-2, 53, 54, 55, 199, 200 and 201. https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
2. Patent Act (특허법), Article 30 in versions before amendment: Act No. 10716 (in force from 1 July 2011), Act No. 11117 (in force from 15 March 2012). https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
3. Act on Partial Amendment of the Patent Act (특허법 일부개정법률), Act No. 21955, promulgated 15 September 2026, to enter into force on 16 March 2027. Articles 30, 200 and 201. https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
4. Enforcement Rules of the Patent Act (특허법 시행규칙), Prime Ministerial Decree No. 2115, in force from 14 May 2026. Articles 10, 20-2, 20-3 and 111. https://www.law.go.kr/법령/특허법시행규칙 (verified 9 October 2026)
5. Regulation on the Collection of Patent Fees, etc. (특허료 등의 징수규칙), Prime Ministerial Decree No. 2098, in force from 27 February 2026. Article 2(1), subparagraph 6-2. https://www.law.go.kr/법령/특허료등의징수규칙 (verified 9 October 2026)
6. Ministry of Intellectual Property (지식재산처), Patent Examination Guidelines (특허·실용신안 심사기준), MOIP Established Rule No. 7, in force from 13 March 2026. Part 1, Chapter 2, 5.; Part 3, Chapter 2, 5.; Part 5, Chapter 3, 4.3 and 4.6; Part 6, Chapter 1, 4.; Part 6, Chapter 4, 4. and 7.5. https://www.law.go.kr/행정규칙/특허·실용신안심사기준 (verified 9 October 2026)
7. Supreme Court Decision 2020Hu11479 Decided August 31, 2022 (대법원 2022. 8. 31. 선고 2020후11479 판결). https://www.law.go.kr/판례/(2020후11479) (verified 9 October 2026)
8. USPTO, Manual of Patent Examining Procedure, Appendix L (Patent Laws), 35 U.S.C. 100(i), 102(a) and (b). https://www.uspto.gov/web/offices/pac/mpep/mpep-9015-appx-l.html (verified 9 October 2026)
9. EPO, European Patent Convention, Article 54, Article 55. https://www.epo.org/en/legal/epc/2020/a54.html , https://www.epo.org/en/legal/epc/2020/a55.html (verified 9 October 2026)
10. e-Gov Laws and Regulations Search (Japan), 特許法 (Patent Act, Act No. 121 of 1959 (昭和三十四年法律第百二十一号)) 第三十条 (Article 30), current text. https://laws.e-gov.go.jp/law/334AC0000000121 (verified 9 October 2026)
11. China National Intellectual Property Administration (国家知识产权局), 中华人民共和国专利法(2020年修正) (Patent Law of the People’s Republic of China, as amended in 2020) 第二十二条, 第二十四条 (Articles 22 and 24), posted 23 November 2020. https://www.cnipa.gov.cn/art/2020/11/23/art_97_155167.html (verified 9 October 2026)
12. Supreme Court Decision 2023Hu10712 Decided May 29, 2025 (대법원 2025. 5. 29. 선고 2023후10712 판결). https://www.law.go.kr/판례/(2023후10712) (verified 9 October 2026)