(1) If a person who intends to obtain grant of a patent registered or a patentee fails to pay a patent fee during the period for late payment or fails to pay an under-paid patent fee during the period for payment of the under-paid patent fee, due to good cause, the person may pay the patent fee or under-paid patent fee within two months from the date when the cause ceases to exist: Provided, That the foregoing shall not apply if one year has elapsed since the expiration of the period for late payment or for payment of the under-paid patent fee, whichever occurs later. <Amended on Oct. 19, 2021>
(2) Notwithstanding Article 81 (3), a person who has paid a patent fee or under-paid patent fee pursuant to paragraph (1) shall be deemed not to have abandoned the patent application, and the patent shall be deemed to survive.
(3) If the patent on an invention has expired due to a patentee's failure to pay a patent fee during the period for late payment or an under-paid patent fee during the period for payment of the under-paid patent fee, the patentee may pay double the patent fee payable under Article 79 within three months from the expiration of the period for late payment or the period for payment of the under-paid patent fee, and files an application for reinstating the expired right. In such cases, the patent shall be deemed to survive.
(4) No patent application or patent referred to in paragraph (2) or (3) shall affect any third person's practice of the invention claimed in the patent application or the patented invention during the period following the expiration of the period for late payment or the period for payment of a deficiency until the date the overdue patent fee or deficiency is paid (hereafter referred to as "period of limited effect" in this Article).
(5) A person who for business purposes practices, or prepares to practice, an invention claimed in a patent application or a patented invention under paragraph (2) or (3) in good faith in the Republic of Korea during a period of limited effect shall have a non-exclusive license over the invention claimed in the patent application within the scope of objectives of the patented invention that the person practices or prepares to practice or objectives of the business.
(6) A non-exclusive license holder prescribed under paragraph (5) shall pay equitable remuneration to the patentee or exclusive licensee.
(7) Matters necessary for making late payment or payment of an under-paid patent fee under the main clause of paragraph (1) or for filing applications under the former part of paragraph (3) shall be prescribed by Ordinance of the Ministry of Trade, Industry and Energy.[This Article Wholly Amended on Jun. 11, 2014]