How does Korean patent practice differ from EPO practice?

Chanjoong Kim, Partner · Published 26 October 2026

Last verified 9 October 2026

At a glance: how Korea and the EPO differ

Amounts are not included in this table. In the table, “Act” means the Korean Patent Act, “Enforcement Rules” means the Enforcement Rules of the Patent Act, and “Fee Regulation” means the Regulation on the Collection of Patent Fees, etc. “EPC” means the articles of the European Patent Convention, and “Rule” means its Implementing Regulations. “Handling Regulations” means the Regulations for the Handling of Patent and Utility Model Examination Affairs. The rows for Europe contain only what was read in the original text of the EPO. [1][3][4][5][6][7]

The time of publication of the application and the term of the patent are similar in the two offices. Korea lays the application open after the lapse of 1 year and 6 months from the date specified in the applicable subparagraph of Art. 64(1) of the Act. The EPO publishes the application after the expiry of 18 months from the date of filing or the date of priority (EPC Art. 93(1)). The term of a Korean patent runs from the date of registration of the grant of a patent (registration of establishment of a patent right) until the date that falls 20 years after the filing date of the patent application (Act, Art. 88(1)). The term of a European patent is 20 years from the date of filing (EPC Art. 63(1)). [1][5]

The amended Patent Act (Act No. 21955), promulgated on 15 September 2026 and entering into force on 16 March 2027, does not change the text of the articles and paragraphs cited in this article. Article 2 of the Addenda to that Act concerns the amended provisions of Art. 81-3 and Art. 87(2). [2]

An application can be filed in English, but the time limit for the translation starts from a different date

In Korea, if the intention is stated in the written patent application, the specification and the captions in the drawings can be written in English (Act, Art. 42-3(1); Enforcement Rules, Art. 21-2(1)). The Korean translation is submitted by the date that falls 1 year and 2 months after the date specified in the applicable subparagraph of Art. 64(1) of the Act. That date is the filing date of the application on which the priority claim is based, or the filing date of the patent application if there is no priority claim. If the applicant is notified of a third party’s request for examination before that time limit, the time limit is the earlier of the date that falls 3 months after the date of the notification and the date that falls 1 year and 2 months after the date specified in the applicable subparagraph of Art. 64(1) (Act, Art. 42-3(2), proviso). If the Korean translation of the specification is not submitted, the application is deemed withdrawn on the day after the time limit (Art. 42-3(4)). Before the Korean translation is submitted, the application cannot be amended, a divisional application cannot be filed, and the applicant cannot request examination (Act, Art. 47(5); Art. 52(1), proviso; Art. 59(2), subparagraph 2). [1][3]

An application can be filed at the EPO in any language. If the language is not an official language, a translation into an official language must be filed within 2 months of filing, and if it is not filed the application is deemed withdrawn (EPC Art. 14(2), Rule 6(1)). Europe counts the time limit for the translation from the filing of the application. Korea counts it from the filing date of the application on which the priority claim is based, or from the filing date of the patent application if there is no priority claim. [5][6]

The time limit for entry of a PCT international application is 31 months in both offices. In Korea, an applicant who filed an international patent application in a foreign language submits the Korean translation within 2 years and 7 months from the priority date (Act, Art. 201(1)). The EPO requires the acts for entry to be performed within 31 months from the date of filing or, if priority has been claimed, from the priority date (Rule 159(1)). In Korea, the translation can be submitted 1 month later if a document stating the intention to extend is submitted in the period from 1 month before the expiration date of the period for submitting domestic documents until that expiration date (Act, Art. 201(1), proviso). The extension is not available if the Korean translation was submitted before that document. If the Korean translation of the description of the invention and the claims is not submitted within the period, the international patent application is deemed withdrawn (Act, Art. 201(4)). The applicant of an international patent application must also submit the document under Art. 203(1) of the Act in the period for submitting domestic documents. The same applies to an international patent application filed in Korean. [1][6]

For details, see “Can I file a patent application in English in Korea?” and “What is the deadline for entering the Korean national phase?“.

The time limit for the request for examination runs from the filing date, not from the search report

In Korea, any person may file a request for examination within 3 years from the filing date of the patent application (Act, Art. 59(2)). The 3 years are the time limit for patent applications filed on or after 1 March 2017. Patent applications filed before that date follow the previous provision (Addenda to Act No. 14035, Art. 19). For an application filed by the legitimate right holder, a divisional application, a separational application (splitting-off) and a converted application, the request can be filed within 30 days from the date on which that application was filed, even after the 3 years have passed (Act, Art. 59(3)). If no request is filed within the period, the application is deemed withdrawn, and a request cannot be withdrawn (Art. 59(4) and (5)). [1]

The EPO draws up and publishes a European search report (EPC Art. 92). The applicant may request examination up to 6 months after the date on which the European Patent Bulletin mentions that publication (Rule 70(1)). The request is not deemed to be filed until the examination fee has been paid (EPC Art. 94(1)). On entry into the European phase through the PCT, if the period under Rule 70(1) has expired earlier, the request for examination is filed within 31 months (Rule 159(1)(f)). If no request is filed within the time limit, the application is deemed withdrawn in both offices (Act, Art. 59(5); EPC Art. 94(2)). [1][5][6]

The 3 years in Korea run from the filing date of the patent application, whatever the result of the search. An international application that designates the Republic of Korea is regarded as a patent application filed on its international filing date (Act, Art. 199(1)). For an international patent application, the time at which examination can be requested is set separately. The applicant can file the request only after submitting the Korean translation and paying the official fees under Art. 82(1) of the Act. An international patent application filed in Korean does not need a Korean translation. A person other than the applicant can file the request only after the period for submitting domestic documents has passed (Act, Art. 210). [1]

For details, see “When must examination be requested in Korea?“.

Korea charges from the first claim, and has no annual fees while the application is pending

The Korean fee for request for examination is a basic fee per case plus an additional fee for each claim (Fee Regulation, Art. 2(1), subparagraph 7). If claims are added by amendment after the request for examination, an official fee is paid for each added claim (subparagraph 9 of the same paragraph). An amendment made when requesting re-examination is excluded from subparagraph 9. The patent fees are also a basic fee for each year plus an additional fee for each claim (Fee Regulation, attached Table 1). The amount of the fee for request for examination depends on the filing date. Where the patent application was filed before 1 August 2023, the previous provisions apply (Fee Regulation, Addenda , Art. 3(2)). For the official fee for added claims, the previous provisions apply where the patent application was filed before 1 May 2024 (Addenda , Art. 3). [4]

The EPO charges claims fees from the 16th claim on an application with more than 15 claims (Rule 45(1)). The same standard applies to an application that has come through the PCT (Rule 162(1)). If the text intended for grant has more than 15 claims and those fees have not yet been paid, they are paid before grant (Rule 71(4)). [6]

The structure of the annual fees also differs. Renewal fees for a European patent application are paid to the EPO from the 3rd year, counted from the date of filing (EPC Art. 86(1)). The due date is the last day of the month containing the anniversary of the date of filing, and the fee can still be paid within 6 months together with an additional fee (Rule 51(1), (2)). If it is not paid within those 6 months either, the application is deemed withdrawn. In Korea, a person who intends to have the grant of a patent registered pays the patent fees for 3 years, and the patentee pays them every year from the following year (Act, Art. 79(1)). Article 79 of the Act does not provide for patent fees on a pending patent application. [1][5][6]

For details, see “How many claims should I keep when entering Korea?“, “How much are Korean patent annual fees, and when are they due?” and “What official fees does a Korean patent cost over its life?“.

Amendments are made only in fixed periods, and the permitted scope narrows at later stages

In Korea, the examiner sets the period for submission of a written argument at up to 4 months (Act, Art. 63(1); Enforcement Rules, Art. 16(1), subparagraph 2). Where time is needed for tests and the measurement of results, the period is set as the time needed for them (Enforcement Rules, Art. 16(1), proviso). The range of up to 4 months was set by the amended Enforcement Rules in force from 11 July 2025 (Ordinance of the Ministry of Trade, Industry and Energy No. 609). The Enforcement Rules before that set the range at up to 2 months. The Addenda to the amended Enforcement Rules contain only the enforcement date and no applicability provision. [1][3]

A period set by the examiner can be extended on request (Act, Art. 15(2)). An extension is requested in units of 1 month (Handling Regulations, Art. 23(2)). If the expiration date of the requested extension is within 4 months from the expiration date of the designated period (specified period), the extension is deemed approved when the request is received (Art. 23(3)). An extension beyond that period can be approved where the examiner finds it necessary (Art. 23(4)). A period specified by the EPO is not less than 2 months and not more than 4 months, and up to 6 months in certain circumstances. In special cases, the period can be extended on a request presented before it expires (Rule 132(2)). [1][6][7]

In Korea, the specification and the drawings can be amended until the certified copy of the decision to grant is served. After a notice of grounds for rejection, however, an amendment can be made only in the period for submission of a written argument under that notice and when re-examination is requested (Act, Art. 47(1)). Amendment of the claims is restricted where the applicant has received a notice of grounds for rejection on a ground for rejection that arose from an amendment, and where re-examination is requested. It is possible only in the cases in the subparagraphs of Art. 47(3) of the Act, such as narrowing the claims, correction of clerical errors and clarification of an ambiguous description. If such an amendment violates Art. 47(2) or (3) of the Act or creates a new ground for rejection, the examiner dismisses it by decision. Amendments that delete a claim, amendments made before a request for re-examination and certain others are exceptions (Act, Art. 51(1)). A decision to dismiss the amendment (decision to reject an amendment) cannot be appealed separately and is contested in the appeal against the examiner’s decision to reject a patent application (trial on rulings rejecting patent applications). A decision to dismiss the amendment made before a request for re-examination, and one made before a decision to grant that was revoked by ex officio re-examination, cannot be contested in that appeal either (Act, Art. 51(3)). [1]

Amendment of a patent application in a foreign language filed in English has one more limit. The amendment must stay within the scope of the original specification or drawings, and also within the scope of the final Korean translation or the original drawings (excluding the captions in the drawings) (Act, Art. 47(2), latter part). For an international patent application filed in a foreign language, that scope is the final Korean translation under Art. 201(5) of the Act and the drawings submitted by the international filing date (Act, Art. 208(4)). An international patent application can be amended only after the official fees have been paid, the Korean translation has been submitted and the reference date has passed (Act, Art. 208(1)). The reference date is the expiration date of the period for submitting domestic documents, or the date of the request if the applicant requested examination in that period (Act, Art. 201(5)). An international patent application filed in Korean does not need a Korean translation. Amendments under Art. 204(2) and Art. 205(2) of the Act are excluded from this restriction. [1]

At the EPO, as a rule, the application cannot be amended before the European search report is received (Rule 137(1)). The applicant can amend of its own volition when replying to a communication under Rule 70a or Rule 161, and further amendments need the consent of the Examining Division (Rule 137(2), (3)). Both offices prohibit amendments that go beyond the content of the application as filed (Act, Art. 47(2), former part; EPC Art. 123(2)). [1][5][6]

The remedies for a missed time limit also differ. The EPO has further processing. The applicant pays the fee and completes the omitted act within 2 months of the communication concerning the failure to observe a time limit (EPC Art. 121, Rule 135(1)). However, some periods, such as the period for appeal, are ruled out from further processing (EPC Art. 121(4), Rule 135(2)). Restoration under Art. 67-3 of the Korean Patent Act concerns the period for requesting examination and the period for requesting re-examination, and it requires good cause. It must be requested within 2 months from the date on which the cause ceases to exist, and it is not available once 1 year has passed from the expiration date of the period. For the period for filing a petition for trial against a decision of rejection, subsequent completion is possible where the period was not observed for a cause not attributable to the person. This too must be done within 2 months from the date on which the cause ceases to exist, and it is not available once 1 year has passed from the expiration date of the period (Act, Art. 17). [1][5][6]

For details, see “How long do I have to respond to a Korean office action? Period for submission of a written argument, extensions and fees“, “When can claims be amended in Korea?” and “What happens if I miss an office action deadline in Korea?”.

A divisional application cannot be filed merely because the application is pending

At the EPO, a divisional application can be filed relating to any pending earlier European patent application (Rule 36(1)). In Korea, an application can be divided only in the periods in the subparagraphs of Art. 52(1) of the Act. [1][6]

After a notice of grounds for rejection, the period in the first row narrows to the period for submission of a written argument and the time when re-examination is requested (Act, Art. 47(1), proviso). A patent application in a foreign language can be divided only if the Korean translation has been submitted (Act, Art. 52(1), proviso). The 3 months in the second row apply beginning with divisional applications based on a patent application for which the certified copy of the decision of rejection is served on or after 20 April 2022 (Addenda to Act No. 18505, Art. 3(1)). Where the appeal against the decision to reject is dismissed, a separational application can be filed within 30 days from the date on which the certified copy of the trial decision is served, and the claims that can be stated in it are restricted (Act, Art. 52-2(1)). A separational application is available beginning with patent applications for which the appeal against the decision to reject is filed on or after 20 April 2022 (Addenda to Act No. 18505, Art. 4). [1]

For details, see “When can I file a divisional application in Korea?“.

After a decision to grant, the patent fees are paid; after a decision of rejection, the applicant chooses re-examination or an appeal

In Korea, the patent fees for the first 3 years are paid in one payment within 3 months from the date of receipt of the certified copy of the decision to grant (Fee Regulation, Art. 8(5)). After that period, they can still be paid within 6 months together with an additional amount (Act, Art. 81(1); Fee Regulation, Art. 8(6)). If they are not paid in the period for late payment either, the patent application is deemed abandoned. If the period for payment of under-paid patent fees has not ended, the time runs until the end of that period (Act, Art. 81(3)). The EPO informs the applicant of the text in which it intends to grant the patent and invites the applicant to pay the fee for grant and publishing and to file a translation of the claims within 4 months. The translation is in the two official languages other than the language of the proceedings (Rule 71(3)). If the applicant pays the fees and files the translations within that period, the applicant is deemed to have approved that text (Rule 71(5)). If the fees are not paid or the translations are not filed, the application is deemed withdrawn (Rule 71(7)). After grant, if a Contracting State so prescribes, a translation of the European patent into an official language of that State must also be supplied to the office of that State (EPC Art. 65(1)). [1][4][5][6]

After a decision of rejection, Korea has two routes. The applicant may request re-examination, with an amendment to the specification or the drawings, within 3 months from the date on which the certified copy of the decision of rejection is served (Act, Art. 67-2(1)). Within the same 3 months, the applicant may also file an appeal against the decision to reject (Act, Art. 132-17). The period for filing a petition for trial can be extended only once, by up to 30 days, and if it is extended, the period for requesting re-examination becomes that extended period (Act, Art. 15(1), Art. 67-2(1)). A person in a remote area or an area with poor access to transport can obtain 1 further extension of up to 30 days (Act, Art. 15(1), proviso; Enforcement Rules, Art. 16(4)). Re-examination cannot be requested where a decision following re-examination has already been made, where a petition for trial has been filed, or where the application is a separational application. A request for re-examination cannot be withdrawn (Act, Art. 67-2(4)). These 3 months apply beginning with patent applications for which the certified copy of the decision of rejection is served on or after 20 April 2022 (Addenda to Act No. 18505, Art. 7 and Art. 11). [1][3]

A decision of the EPO is contested by appeal. The notice of appeal is filed within 2 months of notification of the decision, and it is not deemed to have been filed until the fee for appeal has been paid. The statement setting out the grounds of appeal is filed within 4 months of notification of the decision (EPC Art. 108). [5]

For details, see “What is the deadline to pay the registration fee in Korea?“, “What is re-examination in Korea, and when should it be requested?” and “How do I appeal a decision of rejection in Korea?“.

The request that any person can file after registration has a narrower period and narrower grounds

Any person may file an opposition to a European patent. The period is within 9 months of the publication of the mention of the grant in the European Patent Bulletin (EPC Art. 99(1)). There are three grounds: patentability (EPC Art. 52 to Art. 57), insufficient disclosure, and subject-matter extending beyond the content of the application as filed (EPC Art. 100). [5]

In Korea, what any person can file is a request for revocation of a granted patent (특허취소신청). The period runs from the registration date of the patent until the date that falls 6 months after the date of publication of registration (Act, Art. 132-2(1)). The grounds are a violation of Art. 29 of the Act and a violation of Art. 36(1) to (3). Within Art. 29, the cases that fall under paragraph (1), subparagraph 1 of that Article (inventions publicly known or publicly practiced) and the cases where the invention could easily be made from such an invention are excluded. A request cannot be filed on a ground based on prior art that was included in the grounds for rejection notified by the examiner and was therefore published in the publication of registration (Art. 132-2(2); Act, Art. 87(3), subparagraph 7). The request for revocation of a granted patent applies beginning with patents for which the grant is registered on or after 1 March 2017 (Addenda to Act No. 14035, Art. 10). Other grounds are contested in a trial for invalidation, and a trial for invalidation is requested by an interested party or an examiner (Act, Art. 133(1)). [1]

For details, see “What is a request for revocation of a granted patent in Korea, and what is its deadline?” and “How does a trial for invalidation work in Korea?“.

The disclosure exception is longer and wider in Korea

In Korea, it is sufficient to file the patent application within 12 months from the date on which the invention of the person with the right to obtain a patent came to fall under a subparagraph of Art. 29(1) of the Act (publicly known, publicly practiced, described in a printed publication, and so on). For the purposes of Art. 29(1) and (2) of the Act, the invention is then deemed not to fall under any subparagraph of paragraph (1) of that Article (Act, Art. 30(1)). [1]

The 12 months are counted up to the date on which the patent application is filed in Korea. Even with a priority claim under the Treaty, the application must be filed in Korea within 12 months from the date of disclosure (Patent Examination Guidelines (특허·실용신안 심사기준), Part III, Chapter 2, 5.5.3(5)). Article 54(1) of the Act regards the foreign filing date as the Korean filing date for the purposes of Art. 29 and Art. 36. Article 30 is not in that provision. For an international application that designates the Republic of Korea, the international filing date is the filing date of the patent application (Act, Art. 199(1)). [1][8]

Both a disclosure made by the right holder and a disclosure made against the intention of the right holder are covered. Among disclosures by the right holder, however, the case where the application was laid open or the registration was published, in Korea or abroad, under a treaty or an Act is excluded (Act, Art. 30(1), subparagraph 1, proviso). To rely on this provision for a disclosure made by the right holder, the intention is stated in the written patent application and the supporting documents are submitted within 30 days from the filing date of the patent application (Act, Art. 30(2)). If the supplementary fee is paid, they can also be submitted in the period in which an amendment can be made and in certain other periods (Art. 30(3)). For an international patent application, that document and the supporting documents can be submitted in the period prescribed by Prime Ministerial Decree (Act, Art. 200). [1]

The exception in the European Patent Convention is limited to a disclosure that occurred no earlier than 6 months before the filing of the European patent application. The disclosure must be due to an evident abuse in relation to the applicant or the applicant’s legal predecessor, or to a display at an officially recognised international exhibition (EPC Art. 55(1)). For a display at an exhibition, the applicant must state that fact when filing and file a certificate (Art. 55(2)). A disclosure that can benefit from the disclosure exception in Korea does not benefit from this exception in Europe unless it falls within one of the two cases of Article 55 of the European Patent Convention. [5]

For details, see “What is the grace period under the disclosure exception in Korea?”.

FAQ

How do the fees change if a claim set used at the EPO is filed in Korea as it is?

The EPO charges claims fees from the 16th claim (Rule 45(1)). Korea charges an additional fee for each claim in the fee for request for examination and in the patent fees (Fee Regulation, Art. 2(1), subparagraph 7, attached Table 1). In Korea, a claim set of 15 claims or fewer also carries a fee for each claim.

Does Korea have a procedure like further processing at the EPO?

Further processing at the EPO is a procedure in which the applicant pays the fee and completes the omitted act within 2 months of the communication concerning the failure to observe a time limit (EPC Art. 121, Rule 135(1)). Restoration under Art. 67-3 of the Korean Patent Act concerns the period for requesting examination and the period for requesting re-examination, and it requires good cause. The period for submission of a written argument set by the examiner can be extended on request (Act, Art. 15(2)). An extension is requested in units of 1 month (Handling Regulations, Art. 23(2)).

In Korea, can a divisional application be filed at any time while the application is pending?

No. In Korea, an application can be divided only in the period in which an amendment can be made, within 3 months from the date on which the certified copy of the decision of rejection is served, and within 3 months from the date on which the certified copy of the decision to grant is served (Act, Art. 52(1)). At the EPO, a divisional application can be filed while the earlier European patent application is pending (Rule 36(1)).

Can an invention that was disclosed in Europe more than 6 months ago still be filed in Korea?

Art. 30(1) of the Act applies if the patent application is filed in Korea within 12 months from the date on which the right holder’s invention came to fall under a subparagraph of Art. 29(1) of the Act. The 12 months are counted up to the Korean filing date, not the priority date, and for an international patent application up to the international filing date. However, if the disclosure is the laying-open of an application or the publication of a registration under a treaty or an Act, it is excluded as a disclosure by the right holder (Act, Art. 30(1), subparagraph 1, proviso). Individual cases should be checked with an agent.

How DEFINE IP Law Firm handles this

DEFINE IP Law Firm manages the number of claims as a cost item during prosecution. When a claim set filed at the EPO is to be filed in Korea, we check the number of claims and the times at which amendments can be made together with the applicant before the request for examination. When a notice of grounds for rejection is received, we also review whether a divisional application is needed within the period for submission of a written argument. For questions about the procedural differences between Korea and the EPO, please write to contact@defineip.kr.

Sources

1. Patent Act (특허법), Act No. 21134, in force from 11 November 2025. Articles 15, 30, 42-3, 47, 51, 52, 52-2, 59, 63, 64, 67-2, 67-3, 79, 81, 88, 132-2, 132-17, 133, 199, 200, 201, 203, 208 and 210, and Articles 17, 54 and 87. Articles 29, 36, 82, 204 and 205, which the text cites by number, were read on 10 October 2026. Addenda (Act No. 14035), Articles 1, 10 and 19; Addenda (Act No. 18505), Articles 1, 3, 4, 7 and 11. The enforcement dates of the Addenda were checked in the history list of the Ministry of Government Legislation (법제처). https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
2. Patent Act (특허법), Act No. 21955, promulgated on 15 September 2026, scheduled to enter into force on 16 March 2027. Compared with the articles in source 1; Addenda, Articles 1 and 2. Version history at https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
3. Enforcement Rules of the Patent Act (특허법 시행규칙), Prime Ministerial Decree No. 2115, in force from 14 May 2026. Articles 16 and 21-2. Article 16 before the amendment is from the version in force from 1 November 2024 (Ordinance of the Ministry of Trade, Industry and Energy (산업통상자원부령) No. 579); the version that changed the range to up to 4 months is the version in force from 11 July 2025 (Ordinance of the Ministry of Trade, Industry and Energy No. 609) and its Addenda. https://www.law.go.kr/법령/특허법시행규칙 (verified 9 October 2026)
4. Regulation on the Collection of Patent Fees, etc. (특허료 등의 징수규칙), Prime Ministerial Decree No. 2098, in force from 27 February 2026. Art. 2(1), subparagraphs 7 and 9, Art. 8(5) and (6), attached Table 1, Addenda , Articles 1 and 3, Addenda , Articles 1 and 3. https://www.law.go.kr/법령/특허료등의징수규칙 (verified 9 October 2026)
5. European Patent Office, European Patent Convention. Articles 14, 55, 63, 65, 86, 92, 93, 94, 99, 100, 108, 121, 123. https://www.epo.org/en/legal/epc/2020/a94.html (verified 9 October 2026)
6. European Patent Office, Implementing Regulations to the Convention on the Grant of European Patents. Rules 6, 36, 45, 51, 70, 70a, 71, 132, 135, 137, 159, 161, 162. https://www.epo.org/en/legal/epc/2020/r70.html (verified 9 October 2026)
7. Regulations for the Handling of Patent and Utility Model Examination Affairs (특허·실용신안 심사사무취급규정), MOIP Directive (지식재산처훈령) No. 41, in force from 1 July 2026. Article 23. https://www.law.go.kr/행정규칙/특허·실용신안심사사무취급규정 (verified 9 October 2026)
8. Patent Examination Guidelines (특허·실용신안 심사기준), MOIP Established Rule (지식재산처예규) No. 7, in force from 13 March 2026. Part III, Chapter 2, 5.5.3(5). https://www.law.go.kr/행정규칙/특허·실용신안심사기준 (verified 9 October 2026)