Brief summary
- A Korean patent annual fee can still be paid within 6 months after the payment period. An additional fee of 3% to 18% of the patent fee is added, depending on the time that has passed.
- If the fee is not paid within the 6 months, the patent right is deemed to have lapsed (deemed to have expired). The lapse is retroactive to the day after the end of the period covered by the fees already paid.
- After the lapse, reinstatement can still be requested within 3 months from the expiration date of the 6 months, by paying twice the patent fee. This rule changes on 16 March 2027.
Amounts are taken from the Regulation on the Collection of Patent Fees, etc. (특허료 등의 징수규칙) in force from 27 February 2026. Time limits are taken from the Patent Act (특허법) in force from 11 November 2025. Last verified on 9 October 2026.
Last verified
Stages at a glance
As of October 2026. The Patent Act term is “patent fee” (특허료). The Enforcement Rules of the Decree on Registration of Patent Rights (특허권 등의 등록령 시행규칙) and the guidance of the Ministry of Intellectual Property (지식재산처) call the patent fees from year 4 onward the “annual registration fee” (연차등록료). [5][6] In this article, “annual fee” has the same meaning.
| Stage | Period | Amount to pay | Basis |
|---|---|---|---|
| Normal payment | The year before the fee year. The expiration date is the anniversary of the date of registration of the grant of the patent (registration date) | Patent fee | Patent Act, Art. 79(1); Fee Regulation, Art. 8(8), main clause |
| Late payment | 6 months after the payment period | Patent fee + 3% to 18% | Patent Act, Art. 81(1) and (2); Fee Regulation, Art. 8(8), proviso |
| Payment of under-paid patent fees after a partial payment | 1 month from receipt of the order to pay the under-paid patent fee | The under-paid amount. If it is paid after the payment period or the period for late payment, 3% of the under-paid amount is added | Patent Act, Art. 81-2; Fee Regulation, Art. 8(9) |
| Request for reinstatement after the lapse | 3 months from the expiration date of the period for late payment or the period for payment of under-paid patent fees | Twice the patent fee | Patent Act, Art. 81-3(3); Fee Regulation, Art. 8(10) |
| Where there is good cause | 2 months from the date the cause ceases to exist. Not possible after 1 year from the later of the expiration date of the period for late payment and the expiration date of the period for payment of under-paid patent fees | That patent fee (Ministry of Intellectual Property guidance: the normal payment amount) | Patent Act, Art. 81-3(1) |
The last two rows apply where the period for late payment or the period for payment of under-paid patent fees expired on or before 15 March 2027. For periods that expire later, see “The reinstatement rules change on 16 March 2027” below.
After the payment period, the fee can be paid for 6 months with an additional fee
The patentee can pay the patent fee late, within 6 months after the payment period (Patent Act, Art. 81(1)). [1] The Patent Act calls these 6 months the “period for late payment” (추가납부기간). [1]
In the period for late payment, an additional fee is added to the patent fee. Article 81(2) of the Patent Act sets the upper limit of the amount at twice the patent fee and leaves the specific amount to a Prime Ministerial Decree (총리령). [1] The proviso to Article 8(8) of the Fee Regulation sets the following additional fee rates. [3]
| Counted from the day after the payment period | Additional fee rate |
|---|---|
| Before 1 month has passed | 3% |
| Before 2 months have passed | 6% |
| Before 3 months have passed | 9% |
| Before 4 months have passed | 12% |
| Before 5 months have passed | 15% |
| Before 6 months have passed | 18% |
The patent fees from year 4 onward are paid one year at a time, in the year before the fee year, counted from the registration date (Fee Regulation, Art. 8(8), main clause). [3] The Ministry of Intellectual Property states that the expiration date of the normal payment period is the anniversary of the registration date for that fee year. [6] If the payment date is an official holiday, the fee is paid by the first working day after that date (Fee Regulation, Art. 8(2)). [3][6] Official holidays under this provision include Workers’ Day (근로자의 날) and Saturdays. [3]
In the period for late payment, an interested party who is not the patentee can also pay the patent fee (Patent Act, Art. 80(1)). [1][6]
The patent fees for the first three years, paid after the decision to grant, follow the same structure. The payment period for the first three years is 3 months from receipt of a certified copy of the decision to grant (Fee Regulation, Art. 8(5)). [3] After this period, the fees can still be paid within 6 months at the same additional fee rates (Art. 8(6)). [3] If the fees are not paid within these 6 months either, the patent application is deemed abandoned (Patent Act, Art. 81(3)). [1]
A partial payment leads to an order to pay the under-paid patent fee
If only part of the patent fee has been paid, the Minister of Intellectual Property orders payment of the under-paid patent fee (Patent Act, Art. 81-2(1)). [1] A person who has received the order can pay the under-paid patent fee within 1 month from the date of receipt (Art. 81-2(2)). [1] The Patent Act calls this 1 month the “period for payment of under-paid patent fees” (보전기간). [1]
If the under-paid patent fee is paid after the payment period or the period for late payment, 3% of the under-paid amount is added (Fee Regulation, Art. 8(9), proviso). [3]
Even if the period for late payment has ended, the patent right has not yet lapsed while the period for payment of under-paid patent fees is still running. In that case, Article 81(3) of the Patent Act looks at whether the under-paid patent fee was paid within that period. [1]
If the fee is not paid within the 6 months, the patent right lapses retroactively
If the patent fee is not paid within the period for late payment, the patent right is deemed to have lapsed (Patent Act, Art. 81(3)). [1] The lapse does not take effect at the end of the period for late payment. It is retroactive to the day after the end of the period covered by the fees already paid. [1]
A patent right for which the year-4 fee is not paid lapses retroactively on the day after the end of the period covered by the fees up to year 3 (Patent Act, Art. 81(3)). [1] The Ministry of Intellectual Property describes this point in time as the “day after the expiration date of the normal payment period”. [6] The 6 months of the period for late payment also fall within the time in which the patent right has lapsed.
The Minister of Intellectual Property registers the lapse of the patent right ex officio (Decree on Registration of Patent Rights (특허권 등의 등록령), Art. 14(1), subparagraph 1). [5] When the lapse is registered, the register for that right is closed (Registration Decree, Art. 12(1), subparagraph 1). [5]
Within 3 months after the lapse, reinstatement can be requested by paying twice the fee
There is a period in which reinstatement can be requested even after the patent right has lapsed for non-payment. The patentee can request reinstatement of the patent within 3 months from the expiration date of the period for late payment or the period for payment of under-paid patent fees, by paying twice the patent fee (Patent Act, Art. 81-3(3)). [1] In this case, the patent right is deemed to have continued to exist. [1]
“Twice” is calculated on the patent fee in attached Table 1 of the Fee Regulation (Fee Regulation, Art. 8(10), subparagraph 1). [3] Article 81-3(3) of the Patent Act states no requirement about the reason for the delay. [1]
The request for reinstatement is made in the payment form. The patentee states the request in the payment form, Form 25 of the Enforcement Rules of the Decree on Registration of Patent Rights, and submits it (Enforcement Rules of the Patent Act (특허법 시행규칙), Art. 55-2(2)). [4] The application for registration of reinstatement (Form 19) is not used in this case. [5]
Article 81-3(3) of the Patent Act names “the patentee” as the person who can make the request. [1] The Ministry of Intellectual Property also states that an interested party cannot request reinstatement. [6] For a jointly owned right, one of the right holders can make the request alone. [6]
Article 81-3(3) of the Patent Act covers the case where “the patent right of a patented invention has lapsed”. [1] A patent application that is deemed abandoned because the patent fees for the first three years were not paid is not mentioned in paragraph (3). Such an application is mentioned in paragraph (1) of the same Article (good cause). [1]
With good cause, payment is possible for up to 1 year
There is a separate route where the fee could not be paid within the period for late payment due to good cause. The patent fee or the under-paid patent fee can be paid within 2 months from the date the cause ceases to exist (Patent Act, Art. 81-3(1), main clause). [1] Payment is not possible after 1 year from the later of the expiration date of the period for late payment and the expiration date of the period for payment of under-paid patent fees (Art. 81-3(1), proviso). [1]
In this case, a document proving the good cause is attached to the payment form (Enforcement Rules of the Patent Act, Art. 55-2(1), subparagraph 1). [4] The Ministry of Intellectual Property describes the amount to pay in this case as the “corresponding normal payment amount”. [10]
The Ministry of Intellectual Property states that it recognizes good cause only in limited cases, under a strict standard. [6][10] According to the Ministry, good cause means that the period could not be met even though the patentee took the general care required of a patentee. [10] The Ministry states that not knowing about the duty to pay annual fees, or not receiving the annual fee notice, is not recognized as good cause. [10]
Paragraph (1) applies both to a patentee and to a person who intends to obtain registration of the grant of a patent (registration of establishment of a patent right). [1] Where payment is made under paragraph (1), the patent application is deemed not to have been abandoned, and the patent right is deemed to have continued to exist (Art. 81-3(2)). [1]
The wording “good cause” (정당한 사유) was introduced by an amendment that entered into force on 20 April 2022. Before that, the requirement was “a cause not attributable to the person”. [1]
A reinstated patent has limited effect
A reinstated patent has no effect against acts of working (practice) by other persons during the period of limited effect (효력제한기간) (Patent Act, Art. 81-3(4)). [1] The period of limited effect runs from the day after the period for late payment or the period for payment of under-paid patent fees to the day on which the patent fee or the under-paid patent fee is paid. [1] This applies both to reinstatement under paragraph (3) and to payment under paragraph (1). [1]
A person who, during the period of limited effect, worked the patented invention for business purposes in Korea in good faith, or prepared to do so, has a non-exclusive license (Art. 81-3(5)). [1] The license is limited to the invention being worked or prepared and to the purpose of that business. [1] The holder of this non-exclusive license must pay equitable remuneration to the patentee or the exclusive licensee (Art. 81-3(6)). [1]
The reinstatement rules change on 16 March 2027
The amended Patent Act promulgated on 15 September 2026 (Act No. 21955) revised Article 81-3. The enforcement date is 16 March 2027. [2]
| Item | Current (periods expired on or before 15 March 2027) | Amended (periods expired on or after 16 March 2027) |
|---|---|---|
| Reinstatement regardless of the reason | 3 months from the expiration date, twice the patent fee (paragraph (3)) | Paragraph (3) deleted. Merged into paragraph (1) |
| Requirement of paragraph (1) | Good cause | Excluded only where the non-payment was intentional |
| Period of paragraph (1) | 2 months from the date the cause ceases to exist, and within 1 year from the later expiration date | Within 1 year from the later expiration date |
| Amount | Paragraph (3): twice the patent fee. Paragraph (1): that patent fee | An amount set by Prime Ministerial Decree |
| Covered | Paragraph (3): only a lapsed patent right. Paragraph (1): patent applications and patent rights | Abandoned patent applications and lapsed patent rights |
“Expired” in the table refers to the expiration of the period for late payment or the period for payment of under-paid patent fees. Article 2 of the Addenda to the amending Act provides that the amended Article 81-3 applies to cases in which the period for late payment or the period for payment of under-paid patent fees expires on or after the date the Act enters into force. [2] The reference point is the expiration date of the period for late payment or the period for payment of under-paid patent fees, not the payment period or the registration date.
Cases in which the period for late payment and the period for payment of under-paid patent fees expired before 16 March 2027 are not covered by the amended Article 81-3 (Addenda to the amending Act, Art. 2). [2] The Addenda to the amending Act consist only of Article 1 (Enforcement Date) and Article 2 (Applicability). [2] They contain no transitional measure stating that the previous provision applies to those cases. [2]
The amount under the amended paragraph (1) is left to a Prime Ministerial Decree. [2] As of 9 October 2026, the Fee Regulation in force (Prime Ministerial Decree No. 2098) does not yet contain that amount. [3] Article 81 of the Patent Act, which sets the 6 months of the period for late payment, was not changed by this amendment. [2] As of 9 October 2026, there is no promulgated version of the Fee Regulation, which sets the additional fee rates, that is scheduled to enter into force. [3]
Example: the year-4 fee for a patent with 10 claims
The example assumes a patentee with no fee reduction. The year-4 patent fee is KRW 36,000 plus KRW 20,000 per claim, which is KRW 236,000 (Fee Regulation, attached Table 1). [3] Agent fees are not included.
The registration date is 10 June 2023. The expiration date of the normal payment period for the year-4 fee is 10 June 2026. [6] The day after the payment period is 11 June 2026.
| Time of payment | Stage | Amount to pay |
|---|---|---|
| Until 10 June 2026 | Normal payment | KRW 236,000 |
| From 11 June 2026, before 1 month has passed | Late payment, 3% | KRW 243,080 |
| Before 2 months have passed | Late payment, 6% | KRW 250,160 |
| Before 3 months have passed | Late payment, 9% | KRW 257,240 |
| Before 4 months have passed | Late payment, 12% | KRW 264,320 |
| Before 5 months have passed | Late payment, 15% | KRW 271,400 |
| Before 6 months have passed (until 10 December 2026) | Late payment, 18% | KRW 278,480 |
| Until 10 March 2027 | Request for reinstatement, twice the patent fee | KRW 472,000 |
The periods were calculated under Article 14 of the Patent Act. [1] A period set in months is counted by the calendar and expires on the day before the day in the last month that corresponds to the start date of the period. [1]
The period for late payment for this patent ends on 10 December 2026. If the fee is not paid, the patent right lapses retroactively as of 11 June 2026. [1][6] Because the period for late payment ends before 16 March 2027, the amended Article 81-3 does not apply (Addenda to the amending Act, Art. 2). [2]
The result is different if the registration date is 20 October 2023. The expiration date of the normal payment period for the year-4 fee is 20 October 2026, and the period for late payment ends on 20 April 2027. Because this period expires on or after 16 March 2027, the amended Article 81-3 applies. [2] Unless the non-payment was intentional, reinstatement can be requested within 1 year from that date, and the amount is set by Prime Ministerial Decree. [2]
How Korea differs
The 6-month period for late payment is the same as in the United States and Europe. The differences are in how the additional fee is set and in the remedy after the period has ended.
| Office | Period for payment with an additional fee | Form of the additional fee | After the period |
|---|---|---|---|
| Korea | 6 months after the payment period | 3% for each month, up to 18% | Request for reinstatement within 3 months by paying twice the patent fee. Up to 1 year where there is good cause [1][3] |
| United States | 3.5 to 4 years, 7.5 to 8 years and 11.5 to 12 years from the issue date | Surcharge | Petition with a statement that the delay was unintentional and the petition fee [7][8] |
| Europe (EPO, pending application) | 6 months after the due date | Additional fee | When the 6 months end, the application is deemed withdrawn (EPC, Article 86(1)) [9] |
The USPTO describes 3.5 to 4 years, 7.5 to 8 years and 11.5 to 12 years from the issue date as the periods in which the fee can be paid with a surcharge. [7] The USPTO states that the patent expires if the maintenance fee and the surcharge are not paid by the end of year 4, 8 or 12. [7] After expiry, a delayed payment can be accepted on a petition under 37 CFR 1.378. [8] The USPTO states that it requires additional information for a petition filed more than 2 years after the date of expiry. [7]
The current 3-month reinstatement in Korea does not ask for the reason, but the period is short and the amount is twice the fee. [1] For cases in which the period for late payment expires on or after 16 March 2027, reinstatement can be requested within 1 year unless the non-payment was intentional. [2]
What applicants should do
- In general, we suggest managing the annual fee deadline of a Korean patent by the expiration date of the normal payment period, not by the end of the period for late payment. If the fee is not paid within the period for late payment, the lapse is retroactive.
- For a patent that will not be maintained, we suggest recording that decision before the expiration date of the normal payment period. It should be possible later to tell a missed payment from an intended abandonment.
- If a missed payment is found after the period for late payment has ended, we suggest first checking the expiration date of the period for late payment. The period and the amount differ depending on whether that date is before 16 March 2027 or not.
- Before requesting reinstatement, we suggest reviewing the period of limited effect and the non-exclusive license together. A reinstated patent has no effect against acts of working by other persons during the period of limited effect.
- When acquiring a patent right or taking a license, we suggest checking in the patent register the last fee year paid and whether the right has lapsed.
Please confirm the deadlines and amounts for an individual patent with your agent.
FAQ
How much more is paid if the annual fee is paid one day late?
3% of the patent fee is added. The additional fee rate is 3% until 1 month has passed from the day after the payment period (Fee Regulation, Art. 8(8), proviso, subparagraph 1). [3]
Is the patent right valid during the 6-month period for late payment?
If the fee is paid with the additional fee within the period for late payment, the patent right is not interrupted. [1] If it is not paid, the patent right lapses retroactively on the day after the end of the period covered by the fees paid, not at the end of the period for late payment (Patent Act, Art. 81(3)). [1]
The period for late payment has also ended. Is there any remedy?
Within 3 months from the expiration date of the period for late payment, reinstatement can be requested by paying twice the patent fee (Patent Act, Art. 81-3(3)). [1] Where there is good cause, the fee can be paid within 2 months from the date the cause ceases to exist and within 1 year from the expiration date (Art. 81-3(1)). [1] The amended provision applies to cases in which the period for late payment expires on or after 16 March 2027. [2]
After reinstatement, can the right be enforced against a third party who worked the invention in the meantime?
The patent right has no effect against acts of working during the period of limited effect (Patent Act, Art. 81-3(4)). [1] A person who worked the invention in good faith, or prepared to do so, in that period has a non-exclusive license and must pay equitable remuneration (Art. 81-3(5) and (6)). [1]
What changes from 16 March 2027?
The 3-month reinstatement by paying twice the patent fee is removed. [2] Unless the non-payment was intentional, reinstatement can be requested within 1 year from the expiration date by paying an amount set by Prime Ministerial Decree. [2] The amended provision applies to cases in which the period for late payment or the period for payment of under-paid patent fees expires on or after that date. [2]
How DEFINE IP Law Firm handles this
DEFINE IP Law Firm checks the annual fees of Korean patents against the expiration date of the normal payment period. For a late payment, we first determine the expiration date of the period for late payment and the reinstatement rule that applies. For questions about payment of annual fees and reinstatement of Korean patents, please write to contact@defineip.kr.
Sources
- Patent Act (특허법), Act No. 21134, in force from 11 November 2025. Articles 14, 79, 80, 81, 81-2 and 81-3, Addenda (Act No. 18505, 19 October 2021) Arts. 1 and 9. https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
- Patent Act (특허법), Act No. 21955, promulgated 15 September 2026, in force from 16 March 2027. Articles 81, 81-3 and 87(2), Addenda Arts. 1 and 2. https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
- Ministry of Intellectual Property (지식재산처), Regulation on the Collection of Patent Fees, etc. (특허료 등의 징수규칙), Prime Ministerial Decree No. 2098, in force from 27 February 2026. Article 8(2), (5), (6), (8), (9) and (10), attached Table 1. https://www.law.go.kr/법령/특허료등의징수규칙 (verified 9 October 2026)
- Ministry of Intellectual Property (지식재산처), Enforcement Rules of the Patent Act (특허법 시행규칙), Prime Ministerial Decree No. 2115, in force from 14 May 2026. Article 55-2. https://www.law.go.kr/법령/특허법시행규칙 (verified 9 October 2026)
- Decree on Registration of Patent Rights (특허권 등의 등록령), Presidential Decree No. 35809, in force from 1 October 2025. Articles 12 and 14. Enforcement Rules of the Decree on Registration of Patent Rights (특허권 등의 등록령 시행규칙), Prime Ministerial Decree No. 2062, in force from 28 November 2025. Article 13(4), Form 19. https://www.law.go.kr/법령/특허권등의등록령 (verified 9 October 2026)
- Ministry of Intellectual Property (지식재산처), “[유지등록 (특허·실용신안·디자인권)] 연차등록” (Maintenance of registration: annual registration), last updated 16 December 2025. https://www.kipo.go.kr/ko/kpoContentView.do?menuCd=SCD0200208 (verified 9 October 2026)
- USPTO, “Maintain your patent”, last updated 2 September 2025. https://www.uspto.gov/patents/maintain (verified 9 October 2026)
- 37 CFR 1.378 (eCFR, version current as of 6 October 2026). https://www.ecfr.gov/current/title-37/chapter-I/subchapter-A/part-1/subpart-B/subject-group-ECFR4d7f8a7bd8b4b47/section-1.378 (verified 9 October 2026)
- EPO, European Patent Convention, Article 86(1), Rule 51(2). https://www.epo.org/en/legal/epc/2020/r51.html , https://www.epo.org/en/legal/epc/2020/a86.html (verified 9 October 2026)
- Ministry of Intellectual Property (지식재산처), Industrial property registration system, “자주 문의하는 사항” (Frequently asked questions), item 2, last updated 16 December 2025. https://www.kipo.go.kr/ko/kpoContentView.do?menuCd=SCD0200206 (verified 9 October 2026)