Korea PCT National Phase Deadline: The 31-Month Rule
The Korean national-phase deadline is 31 months from the PCT priority date under both PCT Article 22 and Article 39. If the international application claims no priority, the period is calculated from the international filing date.
Deadline calculation
The calculation should use the earliest valid priority date recorded for the PCT application. The international publication date, search-report date, and instruction date do not control the national-phase period.
The WIPO bibliographic record, priority claims, and applicant docket should be reconciled before Korean filing instructions are issued. If the calculated last day is a non-working day, the applicable Korean rule should be checked against the official calendar.
National-phase requirements
The Korean national-phase filing normally includes:
- the national-phase transmittal document identifying the international application, applicant, and inventor;
- the Korean translation of the description, claims, text in the drawings, and abstract;
- the required treatment and translation of any PCT Article 19 or Article 34 amendments;
- the national filing fee; and
- supporting records for any applicant or bibliographic change that is not reflected in the international record.
WIPO Form No. 57 is recommended for Korean national-phase entry. The filing instruction should identify the exact claim version to be translated and pursued.
One-month translation extension
Article 201(1) of the Korean Patent Act permits a one-month extension for the Korean translation in a defined procedure. The applicant must request the extension in the national-phase document during the one-month period before the 31-month deadline and before submitting the Korean translation.
The national-phase document and national fee still require timely handling. The extension applies to the Korean translation under the statutory conditions and should not be treated as a general extension of the 31-month national-phase deadline.
A long specification, sequence listing, chemical formula, table set, or amended claim package should be instructed early enough for terminology, dependency, and numerical review even when the extension is available.
No routine late national-phase reinstatement
The WIPO Applicant’s Guide states that Korea does not permit reinstatement under PCT Rule 49.6 and does not excuse failure to comply with national-phase time limits. A late fee does not provide routine restoration of a missed Korean national-phase entry.
A suspected missed deadline requires immediate review of the priority record, filing documents, receipt times, and any applicable non-working-day rule. Relief should not be assumed before that review is completed.
Examination request
National-phase entry and substantive examination are separate procedures. A request for examination and the applicable fee are required within three years from the international filing date.
An application entering Korea at 31 months may have approximately five months remaining before the three-year examination-request deadline. Both dates should appear in the initial Korean filing instruction and docket.
Preferential examination
A Korean national-phase application may qualify for preferential examination. PPH or PCT-PPH requires qualifying work product, sufficient correspondence between the Korean claims and claims found allowable, and the prescribed supporting documents.
Current Ministry guidance provides for first examination within approximately three months after the preferential-examination decision in PPH and PCT-PPH cases. The procedure accelerates examination but does not establish patentability.
Filing record
The instruction record should contain the PCT application number, priority date, international filing date, applicant and inventor data, published application, Article 19 and Article 34 amendments, sequence listing, selected Korean claim text, translation-extension decision, examination-request deadline, and any preferential-examination instruction.
Official sources
- WIPO PCT Applicant’s Guide: Republic of Korea
- Ministry of Intellectual Property: Korean PCT national phase
- Korean Patent Act, Article 201
- Ministry of Intellectual Property: Patent Prosecution Highway
Related guidance for Korean patent matters
- Korean Patent Filing by Foreign Companies
- Korean Patent Application Fees and Budget
- Documents Required for a Korean Patent Application
Legal and editorial review: July 16, 2026. Korea’s patent authority is the Ministry of Intellectual Property (MOIP), formerly KIPO.
This article provides general information and does not constitute legal advice. Deadlines, fees, and procedures may change, and the current requirements should be confirmed for each matter.
