How does a trial for invalidation work in Korea?

Chanjoong Kim, Partner · Published 26 October 2026

Last verified 9 October 2026

At a glance

As of October 2026.

An interested party or an examiner files the petition, and there is no time limit

The persons who can request a trial for invalidation are an interested party and an examiner (Patent Act, Art. 133(1)). [1] A request for revocation of a granted patent (특허취소신청) can be filed by any person (Art. 132-2(1)). [1] However, a request for revocation of a granted patent can be filed only from the date of registration of the grant of the patent (registration of establishment of a patent right) until the date that is six months after the date of publication of registration (Art. 132-2(1)). [1] The request for revocation of a granted patent applies to patent rights registered on or after 1 March 2017 (Addenda to Act No. 14035, Art. 10). [1] In a trial for invalidation, the persons who can file the petition are limited.

The Supreme Court of Korea has interpreted “interested party” as follows. An interested party is a person who suffers or is likely to suffer a legal disadvantage from the continued existence of the right in the patented invention, and who therefore has a direct and actual interest in its extinction. [7] This includes a person who manufactures and sells, or will manufacture and sell, goods of the same kind. [7] This is the holding of Supreme Court en banc Decision 2017Hu2819 Decided February 21, 2019. [7]

The same decision also ruled on licensees. The fact that the patentee does not assert the right against a licensee, or that the licensee has no reason to fear that it will, is not, by itself, a reason to find that the interest that allows a request for a trial for invalidation has ceased. [7] The Supreme Court attached the qualification “unless there are special circumstances”. [7]

The provision interpreted in that decision is the first sentence of Art. 133(1) of the Patent Act before its amendment by Act No. 11654, promulgated on 22 March 2013. [7] The current Art. 133(1) names the petitioner with the same words, “interested party”. [1] However, the current provision places a parenthetical limitation after those words. [1]

A petition based on an application by an unentitled person or on a breach of the joint application rule is limited as to the petitioner. In the case of the main clause of Art. 133(1), subparagraph 2, only the person entitled to obtain the patent can file the petition. [1]

Article 133 of the Patent Act contains no wording that sets a time limit for the petition. Article 133(2) provides that a trial for invalidation can be requested even after the patent right has been extinguished. [1]

The petition can be filed claim by claim. Where there are two or more claims, a petition can be filed for each claim (Art. 133(1), latter part). [1] For a patent right with two or more claims, a patent right is deemed to exist for each claim when Art. 133(2) and (3) are applied (Art. 215). [1]

When a trial is requested against the patentee of a jointly owned patent right, all co-owners (joint owners) must be named as respondents (Art. 139(2)). [1] Where two or more persons request a trial for invalidation against the same patent right, they can file the petition jointly (Art. 139(1)). [1]

Patent rights registered before 1 March 2017 are subject to the previous provisions

The current Art. 133(1) was amended by Act No. 14035, promulgated on 29 February 2016. That Act entered into force on 1 March 2017. [1] Article 21 of the Addenda to that Act provides that the previous provisions apply to patent rights registered before it entered into force. [1]

The previous Art. 133(1) named the petitioner only as “an interested party or an examiner”. It had no parenthetical limiting the petitioner for the unentitled person ground to the entitled person. [2] It also had no proviso in subparagraph 2 excluding patents for which a transfer has been registered. [2]

The previous provision had one more proviso. From the registration date until three months after the date of publication of registration, any person could request a trial for invalidation on grounds other than subparagraph 2. [2] That proviso does not exist for patent rights registered on or after 1 March 2017. [1]

There are eight grounds for invalidation, listed in the subparagraphs of Art. 133(1)

A trial for invalidation can be requested where the patent falls under any of the subparagraphs of Art. 133(1) of the Patent Act. [1]

Article 29 provides together for an industrially applicable invention in the main clause of paragraph (1), the subparagraphs of paragraph (1), paragraph (2), and paragraphs (3) and (4). [1] Article 133(1), subparagraph 1 names the whole of Art. 29 as a ground for invalidation. [1] Two cases are excluded from the grounds for a request for revocation of a granted patent. They are the case that falls under Art. 29(1), subparagraph 1, and the case where the invention could easily have been made from an invention under that subparagraph (Art. 132-2(1), subparagraph 1). [1] Article 29(1), subparagraph 1 covers an invention that was publicly known or publicly practiced before the filing. [1]

Two of the description requirements for the specification are grounds for invalidation. One is that the description must be clear and detailed enough for a person skilled in the art to work (practice) the invention easily (Art. 42(3), subparagraph 1). [1] The other is that the claims must be supported by the description of the invention and must be stated clearly and concisely (Art. 42(4)). [1]

The scope of amendment in subparagraph 6 is only the former part of Art. 47(2). The former part refers to the scope of the matters described in the specification or drawings originally attached to the written patent application. [1] The background art requirement (Art. 42(3), subparagraph 2) and the latter part of Art. 47(2) are not among the subparagraphs of Art. 133(1). [1]

The separational application part of subparagraph 7 was introduced by Act No. 18505, promulgated on 19 October 2021. That Act entered into force on 20 April 2022. [1]

The proviso to subparagraph 2 is linked to the claim for transfer of the patent right. If a patent falls under the main clause of subparagraph 2, the person entitled to obtain the patent can ask a court for transfer of the patent right (Art. 99-2(1)). [1] This provision applies to patent rights of unentitled persons registered on or after 1 March 2017 (Addenda to Act No. 14035, Art. 8). [1]

The petition for trial is filed with the President of the IPTAB, and the official fee depends on the number of claims challenged

A person who requests a trial must file a petition for trial with the President of the Intellectual Property Trial and Appeal Board (Patent Act, Art. 140(1)). [1] The petition states the parties, the agent, the identification of the trial case, and the relief sought and its grounds. [1] The form is Form 31 of the Enforcement Rules of the Patent Act (특허법 시행규칙) (Enforcement Rules, Art. 57(3)). [4] If an agent conducts the procedure, a document verifying the agency authority is attached. [4]

A person with no domicile or place of business in Korea (an overseas resident, 재외자) can conduct a patent-related procedure only through a patent administrator (특허관리인) (Art. 5(1)). [1] A patent administrator is an agent with a domicile or place of business in Korea. The exception is where the overseas resident (for a legal entity, its representative) is staying in Korea. [1]

The trial request fee for a trial for invalidation is calculated on “the claims for which there is directly a ground for the trial request” (Fee Regulation, Art. 2(3), subparagraph 3). [3] For an electronic application, the fee is KRW 150,000 per case plus KRW 15,000 per claim. For a paper-based application, it is KRW 170,000 per case plus KRW 15,000 per claim (Art. 2(3), subparagraph 1). [3] These amounts are the same from the version in force from 25 March 2016 to the current version. [3] The Fee Regulation does not set out in more detail how to count those claims. [3]

If the official fee has not been paid or the petition does not comply with the formalities, the presiding administrative patent judge sets a period and orders an amendment (Art. 141(1), main clause). [1] If the matter to be amended is minor and clear, the presiding administrative patent judge can amend it ex officio (Art. 141(1), proviso). [1] If the amendment is not made within the designated period, the presiding administrative patent judge dismisses by decision the petition for trial, or the request or application relating to the procedure concerned (Art. 141(2)). [1] An unlawful petition for trial whose defects cannot be amended can be dismissed by a trial decision without giving an opportunity to file a written response (Art. 142). [1]

An amendment of the petition for trial must not change its gist (Art. 140(2), main clause). [1] An amendment of the grounds for the petition is an exception (Art. 140(2), subparagraph 2). [1] An amendment that corrects the statement of the patentee among the parties is also an exception (Art. 140(2), subparagraph 1). [1] Articles 146, 147 and 149 of the Civil Procedure Act (민사소송법) apply mutatis mutandis to the submission of arguments and evidence (Art. 158-2, the timely submission principle). [1]

When a trial for invalidation is requested, the presiding administrative patent judge must notify the exclusive licensee of the petition. The presiding administrative patent judge must also notify any other person who holds a registered right relating to the patent (Art. 133(4)). [1]

The patentee files a written response within the designated period and can request correction

The presiding administrative patent judge must serve a copy of the petition for trial on the respondent and give an opportunity to file a written response within a set period (Patent Act, Art. 147(1)). [1]

The Patent Act does not fix the length of that period. The Regulation on the Handling of Trial Affairs (심판사무취급규정) sets the period designated by the presiding administrative patent judge at one month or less (Art. 22(1)). [6] The first request to extend the period for the written response can be granted for one month without showing that the extension is unavoidable (Art. 22(3)). [6] Other requests for extension are approved only where it is shown that the extension is unavoidable (Art. 22(2), former part). [6] In fast-track trial cases and certain other cases, the presiding administrative patent judge gives advance notice that later requests for extension will not be approved (Art. 22(2), latter part). [6] The Regulation on the Handling of Trial Affairs is a Directive of the Ministry of Intellectual Property (MOIP, 지식재산처). [6]

For a foreign patentee, service is an issue. If an overseas resident has a patent administrator, documents are served on the patent administrator (Art. 220(1)). [1] If there is no patent administrator, the documents can be sent by registered airmail, and they are deemed served on the date of dispatch (Art. 220(2) and (3)). [1]

The Regulation on the Handling of Trial Affairs has a proviso on right holders who are overseas residents. It applies where there is an agent who was entrusted with trial procedures at the time the right was registered. The presiding administrative patent judge can first notify that agent of the designation of the administrative patent judges and of whether the appointment of the agent is confirmed, and then serve the copy (Art. 23(1), proviso). [6]

The patentee can file a request for correction within the period for the written response. Article 133-2(1) sets two periods in which a request for correction can be filed. They are the period designated under Art. 147(1) and the period designated under the latter part of Art. 159(1). [1] The period under the latter part of Art. 159(1) is the period given for stating an opinion when the administrative patent judges examine a ground that the parties did not plead. [1]

A further opportunity for a request for correction can arise after the period designated under Art. 147(1) has passed. This is where the petitioner has submitted evidence or asserted a new ground for invalidation. If the presiding administrative patent judge finds it necessary to allow a request for correction, the presiding administrative patent judge can set a period for it (Art. 133-2(1), latter part). [1]

A correction can be made only in the three cases of the subparagraphs of Art. 136(1). [1]

A correction must be made within the scope of the matters described in the specification or drawings of the patented invention (Art. 136(3), main clause). [1] For the correction of clerical errors, the reference is the specification or drawings originally attached to the written patent application (Art. 136(3), proviso). [1] A correction must not substantially extend or amend the claims (Art. 136(4)). [1] Both paragraphs apply mutatis mutandis to a request for correction (Art. 133-2(4)). [1]

Article 136(5) contains one more requirement. It applies where the claims are narrowed or clerical errors are corrected. The matters stated in the claims after the correction must be such that a patent could have been obtained at the time the patent application was filed. [1] This paragraph also applies mutatis mutandis to a request for correction (Art. 133-2(4)). [1] However, it does not apply mutatis mutandis where the correction is made to a claim for which the trial for invalidation has been requested (Art. 133-2(6)). [1]

There are five other rules on a request for correction.

• While a trial for invalidation is pending before the IPTAB, a trial for correction (정정심판) cannot be requested separately (Art. 136(2), subparagraph 2). [1]
• If a request for correction is filed again, the earlier request for correction in the same trial for invalidation is deemed withdrawn (Art. 133-2(2)). [1]
• A request for correction can be withdrawn only within fixed periods. These include the period designated for requesting correction and the period of one month from its expiration date (Art. 133-2(5)). [1]
• If there is an exclusive licensee, a pledgee or a non-exclusive licensee of certain kinds, their consent must be obtained (Art. 136(8), applied mutatis mutandis by Art. 133-2(4)). [1] The exception is where the person whose consent is required has requested the trial for invalidation (Art. 136(8), proviso). [1]
• If the patent right is jointly owned, all co-owners must file the request for correction jointly (Art. 139(3), applied mutatis mutandis by Art. 133-2(4)). [1]

The written request for correction is Form 32 of the Enforcement Rules of the Patent Act, and the corrected specification and drawings are attached (Enforcement Rules, Art. 57-2). [4] For an electronic application, the fee for a request for correction is KRW 30,000 per case plus KRW 7,000 for each claim in the claims (Fee Regulation, Art. 2(3), subparagraph 5 (a)). [3] For a paper-based application, it is KRW 40,000 per case plus KRW 7,000 per claim (item (b) of the same subparagraph). [3]

The presiding administrative patent judge must serve a copy of the written request for correction on the petitioner of the trial for invalidation (Art. 133-2(3)). [1]

The proceedings are oral or written, and the judges can examine grounds that were not pleaded

A trial is conducted by oral hearing or by written proceedings (Patent Act, Art. 154(1)). [1] If a party requests an oral hearing, an oral hearing must be held, except where it is found that the case can be decided by written proceedings alone (Art. 154(1), proviso). [1] Korean must be used at the oral hearing (Enforcement Rules, Art. 65(2)). [4]

The Regulation on the Handling of Trial Affairs provides that an oral hearing is held in inter partes cases (Art. 39-2(1)). [6] Exceptions include cases in which no written response was filed and cases found easy to decide on the documents filed. [6]

The administrative patent judges can also examine grounds that a party or an intervenor did not plead. In that case, they must set a period and give an opportunity to state an opinion (Art. 159(1)). [1] They cannot examine relief that the petitioner did not request (Art. 159(2)). [1]

A third party can intervene. A person who can request a trial for invalidation against the same patent right can intervene until the trial examination is closed (Art. 155(1)). [1] A person who has an interest in the result of the trial can intervene to assist one of the parties (Art. 155(3)). [1]

Article 164 governs the relationship with litigation. Where necessary in legal proceedings, a court can suspend the legal proceedings until a decision on a request for revocation of a granted patent or a trial decision on the patent becomes final (Art. 164(2)). [1] Where necessary, the presiding administrative patent judge can also suspend the trial proceedings until a decision on a request for revocation of a granted patent related to the trial case, or a trial decision in another trial, becomes final, or until the legal proceedings are concluded (Art. 164(1)). [1] Both provisions use the wording “can”. [1]

A trial for invalidation related to an infringement dispute is eligible for a fast-track trial (신속심판). Article 31-2(1), subparagraph 1 of the Regulation on the Handling of Trial Affairs names two kinds. One is a trial for invalidation related to an infringement action pending before a court including an application for a provisional disposition against infringement (preliminary injunction), and similar cases. [6] The other is a trial for invalidation requested by a party who received a warning letter or the like from the right holder. [6] A trial in which the parties are not the same as in the related case before the court or other body is excluded. [6] A party must file a request for a fast-track trial, and the presiding administrative patent judge decides whether the case qualifies. [6]

The schedule of a fast-track trial case is in Art. 31-2(3). The oral hearing is held within one month from the later of the expiration date of the period for the written response and the date of the decision to conduct a fast-track trial. [6] If a request for correction has been filed, the reference is the expiration date of the period for the petitioner’s written argument on the request for correction, in place of the expiration date of the period for the written response. [6] The trial decision is made within two weeks from the latest of the dates in the subparagraphs of that paragraph, such as the date of the oral hearing. Cases recognized by the President of the Intellectual Property Trial and Appeal Board are an exception. [6] For cases in which an oral hearing is found unnecessary, Art. 31-2(4) sets the time of the trial decision separately. [6]

With the consent of the parties, the presiding administrative patent judge can suspend the trial proceedings and refer the case to the mediation committee (Art. 164-2(1)). [1] If mediation is concluded, the petition for trial is deemed withdrawn (Art. 164-2(3)). [1]

When a trial decision of invalidation becomes final, the patent right is deemed never to have existed

When the case is ripe for a trial decision, the presiding administrative patent judge must notify the parties and intervenors of the closure of the trial examination (Patent Act, Art. 162(3)). [1] The trial decision is made within 20 days from the date of the notice of closure of the trial examination (Art. 162(5)). [1] Documents filed after the notice of closure are not taken into account in the trial decision (Enforcement Rules, Art. 66(1)). [4]

When a trial decision invalidating a patent becomes final, the patent right is deemed never to have existed (Art. 133(3), main clause). [1] Invalidation on the ground of subparagraph 4 is different. In that case, the patent right is deemed not to have existed from the time the patent came to fall under subparagraph 4 (Art. 133(3), proviso). [1]

When a trial decision of invalidation becomes final, the patent fees for the years from the year after the year in which it became final are refunded at the request of the person who paid them (Art. 84(1), subparagraph 2). [1]

A final trial decision has the effect of res judicata (일사부재리), a bar on a repeated petition for trial on the same facts and evidence. Once a trial decision is final, no person can request a trial again on the basis of the same facts and the same evidence (Art. 163, main clause). [1] This does not apply where the final trial decision is a trial decision of dismissal (Art. 163, proviso). [1] There are two reference times for res judicata. Whether the earlier trial decision has become final is assessed as of the time the petition for trial was filed. [8] This is Supreme Court en banc Decision 2009Hu2234 Decided January 19, 2012. [8] The provision interpreted in that decision is Art. 163 of the Patent Act before its amendment by Act No. 6411, promulgated on 3 February 2001. [8] That provision read “when a trial decision has become final and been registered, or a judgment has become final”, and the decision also ruled by reference to the time when the trial decision in another trial became final and was registered. [8] The current Art. 163 reads “when a trial decision has become final”. [1] Where a trial decision in another trial becomes final after the petition for trial was filed, the petition does not become unlawful by res judicata. [8] Whether the petition is based on the same facts and evidence as the earlier final trial decision is assessed as of the time of the trial decision. [12] This is Supreme Court Decision 2018Hu11360 Decided April 9, 2020. [12] That decision stated that Decision 2009Hu2234 changed the reference time only for the finality of the earlier trial decision. [12]

A petition for trial can be withdrawn until the trial decision becomes final. After a written response has been filed, the consent of the other party is required (Art. 161(1)). [1] Where a trial for invalidation was requested for two or more claims, the petition can be withdrawn claim by claim (Art. 161(2)). [1] If the petition for trial is withdrawn before the notice of closure of the trial examination is received, one half of the trial request fee is refunded (Art. 84(1), subparagraph 11). [1]

The allocation of trial costs is determined in the trial decision (Art. 165(1)). [1] The remuneration of a patent attorney who acted as agent in the trial is treated as trial costs within the amount set by the Minister of Intellectual Property (Art. 165(7)). [1]

A revocation action is filed with the IP High Court of Korea within 30 days

A revocation action is under the exclusive jurisdiction of the IP High Court of Korea (Patent Act, Art. 186(1)). [1] The action must be filed within 30 days from the date on which the certified copy of the trial decision is served, and this period is an invariable period (Art. 186(3) and (4)). [1] The presiding administrative patent judge can set an additional period ex officio (Art. 186(5)). [1] It is for a person whose domicile or residence is in a remote area or in an area with poor access to transport. [1] The Regulation on the Handling of Trial Affairs provides that an additional period of up to 30 days can be designated ex officio or on request (Art. 88(2)). [6] As a rule, the designation of the additional period is stated in the operative part of the written trial decision (Art. 88(3)). [6]

The Supreme Court of Korea held that Art. 161 of the Civil Act (민법), not Art. 14, subparagraph 4 of the Patent Act, applies to the calculation of the period for filing a revocation action. [13] This is Supreme Court Decision 2013Hu1573 Decided February 13, 2014. [13] That decision interpreted the Patent Act before its amendment of 3 March 2006. [13] The Supreme Court found that the procedure for a revocation action is not included in a “patent-related procedure”. [13] Article 161 of the Civil Act provides that if the last day of a period is a Saturday or a public holiday, the period expires on the following day. [14] Article 14, subparagraph 4 of the Patent Act includes Workers’ Day (노동절) in official holidays (public holidays). [1] Article 161 of the Civil Act does not mention Workers’ Day. [14] However, Article 2, subparagraph 5 of the Act on Public Holidays (공휴일에 관한 법률) makes Workers’ Day (1 May) a public holiday from 1 May 2026. [15]

The persons who can file the action are a party, an intervenor, and a person whose request to intervene was refused (Art. 186(2)). [1] In a revocation action against a trial decision in a trial for invalidation, the defendant is the petitioner or the respondent of the trial, not the Minister of Intellectual Property (Art. 187, proviso). [1]

The Supreme Court of Korea held that, in a revocation action, a party can assert and prove grounds of illegality that were not decided in the trial decision. [9] This is Supreme Court Decision 2000Hu1290 Decided June 25, 2002. [9] It held that the court can examine and decide them without restriction unless there are special circumstances. [9] There is an exception. It is different in a revocation action against a trial decision that dismissed a petition for trial for invalidation for breach of res judicata. The petitioner cannot assert a new ground for invalidation that was not asserted in the trial procedure. [12]

If a court gives a judgment revoking a trial decision and the judgment becomes final, the administrative patent judges must examine the case again and make a trial decision (Art. 189(2)). [1] The reasons on which the revocation in the judgment is based bind the IPTAB in that case (Art. 189(3)). [1] An appeal against the judgment of the IP High Court of Korea can be filed with the Supreme Court of Korea (Art. 186(8)). [1]

Example: official fees

The amounts assume that the petition for trial is filed as an electronic application and that there is no fee reduction. Agent fees are not included. The number of claims is the number of “the claims for which there is directly a ground for the trial request” under Art. 2(3), subparagraph 3 of the Fee Regulation. [3]

A patentee who files the written request for correction as an electronic application pays KRW 30,000 plus KRW 7,000 for each claim in the claims. [3] The fee for a request for extension of a designated period is KRW 20,000 for the part of the extension up to one month (Fee Regulation, Art. 2(3), subparagraph 11-2 (a)). [3]

How Korea differs

The Korean trial for invalidation differs from inter partes review in the United States in who can file and in the scope of the grounds. Article 123(2) of the Japanese Patent Act (特許法 第123条 第2項) limits the petitioner of a trial for patent invalidation (特許無効審判) to an interested party (利害関係人). [11] Article 133(1) of the Korean Patent Act names an examiner as a petitioner in addition to an interested party. [1]

The USPTO guidance states that the timing limit of 311(c) applies to first-inventor-to-file patents. [10] It states that the limit does not apply to first-to-invent patents. [10]

The United States has a time limit linked to infringement litigation. A review cannot be instituted on a petition filed more than 1 year after the date on which the petitioner or a related person was served with a complaint alleging infringement (35 U.S.C. 315(b)). [10] Article 133 of the Korean Patent Act has no time limit for the petition that is linked to the filing of an infringement action. [1]

United States law requires a time limit for the final determination. It is within 1 year from the date of the notice of institution, and it can be extended by up to 6 months for good cause (35 U.S.C. 316(a)(11)). [10] Article 162(5) of the Korean Patent Act provides that the trial decision is made within 20 days from the date of the notice of closure of the trial examination. [1]

A patentee in the United States can file one motion to amend in an inter partes review (35 U.S.C. 316(d)(1)). [10] Additional motions can be permitted in the cases set by 316(d)(2). [10] A Korean patentee files a request for correction within the designated period, and if the request is filed again, the earlier request for correction is deemed withdrawn (Art. 133-2(1) and (2)). [1]

Japan also limits the petitioner for the unentitled person ground to the person who has the right to obtain the patent (Japanese Patent Act, 第123条 第2項). [11]

What applicants should do

• For a company that plans to request a trial for invalidation, in general we suggest having the grounds for invalidation and the evidence ready at the stage of the petition for trial. The patentee’s request for correction is prepared in response to the petitioner’s arguments and evidence.
• We suggest preparing material that shows the interest before filing the petition. An example is material showing that the company manufactures and sells goods of the same kind or plans to do so.
• If the case is related to an infringement action or a warning letter, a request for a fast-track trial is worth considering.
• For a foreign company that holds a Korean patent, we suggest keeping a patent administrator appointed. Without a patent administrator, documents can be treated as served on the date of dispatch.
• We suggest that the patentee decide whether to request correction within the period for the written response. The patentee should first check that the proposed correction still covers the embodiment against which it intends to assert infringement.
• For a patent with a licensee or a pledgee, we suggest checking in advance the consent needed for a request for correction.
• Please check with a Korean agent on the prospects of invalidation and the response in an individual case.

FAQ

Can a licensee request a trial for invalidation in Korea?

The Supreme Court of Korea held that, unless there are special circumstances, the interest cannot be found to have ceased merely because the patentee does not assert the right against the licensee, or the licensee has no reason to fear that it will. [7] This is Supreme Court en banc Decision 2017Hu2819 Decided February 21, 2019. [7] That decision interpreted Art. 133(1) of the Patent Act before its amendment by Act No. 11654, promulgated on 22 March 2013. [7] The current Art. 133(1) also names the petitioner as an “interested party”. [1] However, in the case of the main clause of Art. 133(1), subparagraph 2, only the person entitled to obtain the patent can file the petition. [1]

Can a trial for invalidation be requested after the term of the patent has ended?

Yes. Article 133(2) of the Patent Act provides that a trial for invalidation can be requested even after the patent right has been extinguished. [1]

Can a trial for correction be requested separately while the trial for invalidation is in progress?

No. A trial for correction cannot be requested while a trial for invalidation is pending before the IPTAB (Patent Act, Art. 136(2), subparagraph 2). [1] The patentee files a request for correction within the designated period in the procedure of the trial for invalidation (Art. 133-2(1)). [1]

If an infringement action is pending, does the court wait for the result of the trial for invalidation?

Not necessarily. Article 164(2) of the Patent Act provides that the court can suspend the legal proceedings where necessary. [1] A trial for invalidation related to an infringement action can become a fast-track trial if a party requests it (Regulation on the Handling of Trial Affairs, Art. 31-2). [6]

If a petition for trial for invalidation is dismissed on the merits, can it not be filed again?

Only a petition based on the same facts and the same evidence is barred. Once a trial decision is final, no person can request a trial again on the basis of the same facts and the same evidence (Patent Act, Art. 163, main clause). [1] This does not apply where the final trial decision is a trial decision of dismissal (Art. 163, proviso). [1]

How DEFINE IP Law Firm handles this

In cases of a trial for invalidation, DEFINE IP Law Firm reviews the grounds for invalidation together with the scope in which correction is possible before filing the petition for trial or the written response. When we represent the patentee, we manage the period in which a request for correction can be filed as a deadline. Where an infringement action is running in parallel, we look at the schedules of the two procedures together. For questions about trials for invalidation of Korean patents, please write to contact@defineip.kr.

Sources

1. Patent Act (특허법), Act No. 21134, in force from 11 November 2025. Articles 5, 25, 29, 32, 33, 36, 42, 44, 47, 52, 52-2, 53, 84, 99-2, 132-2, 133, 133-2, 136, 139, 140, 141, 142, 146, 147, 154, 155, 158-2, 159, 161, 162, 163, 164, 164-2, 165, 186, 187, 189, 215, 220 and 14; Addenda (Act No. 14035, 29 February 2016) Arts. 1, 8, 10 and 21; Addenda (Act No. 18505, 19 October 2021). https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
2. Patent Act (특허법), Act No. 13096, in force from 29 July 2015 (Art. 133(1) before the amendment). Version history at https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
3. 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. Art. 2(3), subparagraphs 1, 3, 5 and 11-2. Compared with earlier versions (Ordinance of the Ministry of Trade, Industry and Energy No. 187, in force from 25 March 2016, and others). https://www.law.go.kr/법령/특허료등의징수규칙 (verified 9 October 2026)
4. Ministry of Intellectual Property (지식재산처), Enforcement Rules of the Patent Act (특허법 시행규칙), Prime Ministerial Decree No. 2115, in force from 14 May 2026. Articles 57, 57-2, 65 and 66. https://www.law.go.kr/법령/특허법시행규칙 (verified 9 October 2026)
5. Patent Act (특허법), Act No. 21955, promulgated on 15 September 2026, to enter into force on 16 March 2027. Compared article by article with the current version. Version history at https://www.law.go.kr/법령/특허법 (verified 9 October 2026)
6. Ministry of Intellectual Property (지식재산처), Regulation on the Handling of Trial Affairs (심판사무취급규정), MOIP Directive No. 35 (지식재산처훈령 제35호), in force from 29 June 2026. Articles 22, 23, 31-2, 39-2 and 88. https://www.law.go.kr/행정규칙/심판사무취급규정 (verified 9 October 2026)
7. Supreme Court of Korea (대법원), Supreme Court en banc Decision 2017Hu2819 Decided February 21, 2019 (대법원 2019. 2. 21. 선고 2017후2819 전원합의체 판결). https://www.law.go.kr/판례/(2017후2819) (verified 9 October 2026)
8. Supreme Court of Korea (대법원), Supreme Court en banc Decision 2009Hu2234 Decided January 19, 2012 (대법원 2012. 1. 19. 선고 2009후2234 전원합의체 판결). https://www.law.go.kr/판례/(2009후2234) (verified 9 October 2026)
9. Supreme Court of Korea (대법원), Supreme Court Decision 2000Hu1290 Decided June 25, 2002 (대법원 2002. 6. 25. 선고 2000후1290 판결). https://www.law.go.kr/판례/(2000후1290) (verified 9 October 2026)
10. United States Code, Title 35, §311, §315, §316 (2024 Edition, U.S. Government Publishing Office). https://www.govinfo.gov/link/uscode/35/311 (verified 9 October 2026). USPTO, Inter Partes Review, updated 10 October 2022. https://www.uspto.gov/patents/ptab/trials/inter-partes-review (verified 9 October 2026)
11. Japanese Patent Act (特許法, 昭和三十四年法律第百二十一号), 第123条, e-Gov 法令検索 (version reflecting the amendment in force from 24 June 2026). https://laws.e-gov.go.jp/law/334AC0000000121 (verified 9 October 2026)
12. Supreme Court of Korea (대법원), Supreme Court Decision 2018Hu11360 Decided April 9, 2020 (대법원 2020. 4. 9. 선고 2018후11360 판결). https://www.law.go.kr/판례/(2018후11360) (verified 9 October 2026)
13. Supreme Court of Korea (대법원), Supreme Court Decision 2013Hu1573 Decided February 13, 2014 (대법원 2014. 2. 13. 선고 2013후1573 판결). https://www.law.go.kr/판례/(2013후1573) (verified 9 October 2026)
14. Civil Act (민법), Act No. 21454, in force from 17 March 2026. Article 161. https://www.law.go.kr/법령/민법 (verified 9 October 2026)
15. Act on Public Holidays (공휴일에 관한 법률), Act No. 21338, in force from 11 May 2026. Article 2. Article 2, subparagraph 5 was added by the version in force from 1 May 2026 (Act No. 21543). https://www.law.go.kr/법령/공휴일에관한법률 (verified 9 October 2026)