1. Extension for regulatory approval
Patents for medicines and agrochemicals containing a new active ingredient, first approved or registered in Korea, can be extended for the period in which the invention could not be worked because of the approval process:
- Up to 5 years, once. Time attributable to the approval holder is not counted.
- For approvals obtained since 22 July 2025, the extended term cannot run more than 14 years from the approval, and only one patent can be extended per approval; applying for two or more means none is extended.
- Apply within three months of the approval, and not within the last six months of the patent term. Co-owners must apply together.
- The term is treated as extended while the application is pending.
2. Extension for registration delay
If a patent is registered later than four years from the filing date or three years from the examination request, whichever is later, the term can be extended by the delay, less the delays caused by the applicant. For a PCT application, the four years run from the date the national phase submission was filed.
Apply within three months of registration. The applicant's delays are deducted, such as extensions of response periods.
Working with us
When we report a registration, we check whether a delay extension is available and tell you the deadline. For regulatory extensions, send us the approval as soon as it is issued.
Questions
How long is a Korean patent term?
20 years from the filing date, subject to extensions for regulatory approval and for registration delay.
How long can a Korean patent be extended for regulatory approval?
Up to 5 years, once, for medicines and agrochemicals with a new active ingredient. For approvals since 22 July 2025, the extended term cannot exceed 14 years from the approval, and only one patent can be extended per approval.
When must the extension be applied for?
Within three months of the approval for a regulatory extension, and within three months of registration for a registration-delay extension.
How is registration delay calculated for a PCT application?
The four years run from the date the national phase submission was filed in Korea, and delays caused by the applicant are deducted.
Legal basis
- Patent Act, Art. 88 — 20-year term
- Patent Act, Art. 89, Patent Act, Art. 90 — regulatory extension: 5 years, 14-year cap, three-month deadline, one patent per approval (paras. 7 and 8)
- Enforcement Decree of the Patent Act, Art. 7 — medicines, narcotics and agrochemicals with a new active ingredient
- Act No. 20700 (21 January 2025), Addendum Arts. 1 and 2 — in force 22 July 2025, for approvals obtained from that date
- Patent Act, Art. 92-2, Patent Act, Art. 92-3 — registration-delay extension: calculation, PCT start date (para. 4), three months from registration