Does Korea accept letters of consent for similar marks?

Jonghwan Choi, Managing Partner · Published 28 October 2026

Last verified 9 October 2026

At a glance

A similar trademark can be registered with consent

Art. 34(1), subparagraph 7 of the Trademark Act makes it a ground for rejection that a trademark is identical or similar to the registered trademark of another person based on an earlier application. The proviso to the same subparagraph provides that the trademark can be registered if the applicant has obtained the consent of that other person to the trademark registration. [1]

The same applies where the earlier trademark is an application that is not yet registered. Art. 35(6) provides that the later applicant can also obtain registration with the consent of the earlier applicant. Where the applications were filed on the same day, the consent of the applicant determined by consultation between the applicants or by lot is required. [1]

The two provisions have the same exception. Where an identical trademark is used on goods identical to the designated goods, the trademark cannot be registered even with consent. [1]

Before 1 May 2024, Art. 34(1), subparagraph 7 of the Trademark Act had no proviso, and Art. 35 had no paragraph (6). [3] At that time, the ground for rejection remained even if the right holder of the earlier registered trademark consented.

The provisions can also apply to applications filed before 1 May 2024

The consent provisions entered into force on 1 May 2024. Act No. 19809 was promulgated on 31 October 2023, and Art. 1 of its Addenda sets the enforcement date as the day on which 6 months have passed after promulgation. [1]

The relevant point in time is the decision on whether to grant trademark registration, not the filing date. Art. 2 of the Addenda provides that the consent provisions apply where the decision on whether to grant trademark registration is made on or after entry into force, even if the application was filed before it. [1] This covers trademark applications, converted applications, divisional applications and applications for registration of additional designated goods. [1] The decision on whether to grant trademark registration means the decision to reject trademark registration or the decision to grant trademark registration (decision to register a trademark) (Art. 34(2)). [1]

An international application under the Madrid Protocol that designates Korea is deemed a trademark application under the Trademark Act (Art. 180(1)). [1] The proviso to Art. 34(1), subparagraph 7 and Art. 35(6) therefore also apply to an application for international trademark registration (국제상표등록출원). The special provisions in Art. 181 to Art. 208 of the Trademark Act contain no article that excludes these two provisions. [1] The sample letter of consent in the Trademark Examination Guidelines also shows the international registration number together with the application number in the field for the application number. [4]

The scope of amendment is different for an application for international trademark registration. The designated goods can be amended only where a notification of grounds for rejection under Art. 55(1) has been received (Art. 185(1)). [1] Art. 55-2 on requests for re-examination also does not apply (Art. 193-2). [1]

The letter of consent is attached to the written application for trademark registration or a written opinion

An applicant who has obtained consent attaches a document that can prove the consent to the prescribed form and files it (Enforcement Rules of the Trademark Act (상표법 시행규칙), Art. 26-2(1)). [2] The Enforcement Rules set five occasions.

The period for submitting a written opinion against a notification of grounds for rejection is a period set by the examiner, up to 2 months (Enforcement Rules, Art. 50(2)). [2] The examiner can extend the period that the examiner has set, on the request of the person conducting the procedure or the agent (Trademark Act, Art. 17(2)). [1] An applicant who did not file a written opinion within that period can apply for continuing trademark-related procedures and file the written opinion within 2 months from the expiration date of the period (Trademark Act, Art. 55(3)). [1]

A letter of consent that was not filed together with the written opinion can be filed attached to a written amendment (Enforcement Rules, Art. 26-2(2)). [2] For an application with a decision to publish the application, this is possible until publication of the application. Where there is no decision to publish the application, it is possible until the decision to reject trademark registration (Trademark Act, Art. 40(1), subparagraphs 1-2 and 2). [1][2] Where the examination provisions apply mutatis mutandis in an appeal against the decision to reject and a written opinion is filed, it is possible within the period for submitting that written opinion (subparagraph 4 of the same paragraph). [1][2]

A letter of consent that was not attached to the written application for trademark registration can be filed with a written amendment within the periods in the subparagraphs of Art. 40(1) and Art. 41(1) of the Trademark Act (Enforcement Rules, Art. 26-2(2), subparagraph 4). [2] A letter of consent that was not attached to the written answer to an opposition can be filed with a written amendment within the period for the written answer (subparagraph 2 of the same paragraph; Trademark Act, Art. 41(1), subparagraph 3). [1][2]

Where the letter of consent is filed with the request for trial, it can be filed with a written amendment within 30 days from the date of the request for trial (Enforcement Rules, Art. 26-2(2), subparagraph 5; Trademark Act, Art. 40(1), subparagraph 3). [1][2] An appeal against the decision to reject is requested within 3 months from the date on which the certified copy of the decision to reject trademark registration is served (Trademark Act, Art. 116). [1] A letter of consent that was not attached to a written opinion in the appeal can be filed with a written amendment from the date of the request for trial until the date of the notice of closure of the trial examination (Enforcement Rules, Art. 26-2(2), subparagraph 3). [2]

An amendment that files or corrects a letter of consent is not regarded as a change of the substance of the application (Enforcement Rules, Art. 33, subparagraph 5). [2] This provision also applies where a letter of consent is filed on or after 1 May 2024 for an application filed before that date (Addenda to Ordinance of the Ministry of Trade, Industry and Energy No. 555, Art. 2). [2]

Conditional and blanket letters of consent are not accepted

The Trademark Examination Guidelines of the Ministry of Intellectual Property (지식재산처) set three kinds of letter of consent that are not accepted. [4]

• A conditional letter of consent: one with a condition such as a limit in time or territory, or the exclusion of part of the legal effect
• A blanket letter of consent: one that, for example, consents to all applied-for trademarks that contain the main part A
• A letter of consent for an applied-for trademark for which both the mark and the designated goods are identical

The Trademark Examination Guidelines list seven required entries in a letter of consent. They include the name of the individual or the corporation, the signature or seal, the applicant code (특허고객번호), and the registration number or application number. They also include the designated goods for which registration is consented to, a confirmation of the matters to be entered in the trademark register, and the date of consent. [4] If there is no applicant code, the reason is stated. [4]

There is one opportunity to correct a defective letter of consent. If a letter of consent attached to a written opinion or a written amendment has a defect, such as a missing required entry, the examiner sends an advance notice of a decision to reject trademark registration. If a valid letter of consent is still not filed after that, the examiner issues a decision to reject trademark registration. The same applies where a letter of consent that is not accepted has been filed. [4]

Consent can also be given for only some of the designated goods. In that case, the ground for rejection is overcome only for the designated goods consented to. [4]

If there are several conflicting earlier trademarks, the consent of all right holders of the earlier registered trademarks and all earlier applicants is required. [4]

One party cannot withdraw the consent alone. The Trademark Examination Guidelines state that a withdrawal by agreement between both parties can be accepted, but a withdrawal by one party is not accepted. [4]

If the earlier trademark is still a pending application, the examination of the later application is delayed. The Trademark Examination Guidelines provide that consent to registration is applied after the earlier application has been registered, and that examination is suspended before that. [4] Where the applications were filed on the same day, it is applied after the applicant with priority has been determined by consultation between the applicants or by lot. A letter of consent filed before that is not applied in the examination. [4]

In principle, consent to registration is not applied to applications for collective marks, certification marks or business emblems. [4]

Consent overcomes only the grounds under Art. 34(1), subparagraph 7 and Art. 35

The grounds for rejection that a letter of consent overcomes are Art. 34(1), subparagraph 7, Art. 35(1) and Art. 35(2) of the Trademark Act. The Trademark Examination Guidelines state that a letter of consent is not applied to other grounds for rejection. [4]

In Art. 34(1) of the Trademark Act, the subparagraph with a proviso on consent is subparagraph 7. Subparagraph 9, on a trademark of another person that is widely recognized among consumers, has no such proviso. Subparagraph 11, on confusion with the goods or business of another person that are remarkably recognized among consumers, also has no such proviso. The same is true of subparagraph 12, on misleading as to quality and deceiving consumers, and of subparagraph 13, on an unfair purpose. [1]

A conflict with a registered collective mark with geographical indication is a ground for rejection under subparagraph 8, not subparagraph 7. Consent to registration does not apply here either. [1][4]

Where the examiner finds that the two trademarks are not similar, the letter of consent is not applied in the examination. [4]

After registration, both trademarks can be subject to a trial to cancel trademark registration

A trademark registered with consent has the same effect as an ordinary registered trademark. A letter of consent does not need to be filed again at registration to renew the duration of the trademark right. [4]

For both the earlier registered trademark and the later trademark registered with consent, the trademark register indicates that the trademark is a registered trademark based on coexistence consent. [4]

Art. 119(1), subparagraph 5-2 of the Trademark Act sets a separate ground for cancellation for trademarks registered with consent. [1] It covers one of two persons: the right holder of the trademark registered with consent, or the person who consented to that trademark registration. [1] The first requirement is that this person used its own registered trademark, for the purpose of unfair competition, on goods identical or similar to the designated goods. [1] The second requirement is that this use misled consumers as to the quality of the goods or caused confusion with goods connected with the business of another person. [1]

Anyone can request this trial to cancel trademark registration (Art. 119(5)). [1] It cannot be requested after 3 years from the date on which the facts that constitute the ground for cancellation ceased to exist (Art. 122(2)). [1] When the trial decision of cancellation becomes final, the trademark right is extinguished from that time (Art. 119(6)). [1]

The party whose registration is cancelled cannot register the same trademark again immediately (Art. 34(3)). [1] This applies to the trademark right holder for whom a trial decision of cancellation became final on or after the date of the request for the trial to cancel trademark registration, and to a person who uses that trademark. [1] On an application filed before 3 years have passed from the date on which the decision became final, they cannot register an identical or similar trademark on identical or similar goods. [1] The same restriction applies where, on or after the date of the request for trial, the trademark right is extinguished by expiry of its term. It also applies where the trademark right or some of the designated goods are abandoned. [1]

A trademark registered in breach of the consent provisions is subject to a trial to invalidate trademark registration. A violation of Art. 34 or Art. 35 is a ground for invalidation (Art. 117(1), subparagraph 1). [1] An interested party or an examiner can request the trial to invalidate trademark registration (Art. 117(1)). [1] A trial to invalidate trademark registration based on Art. 34(1), subparagraph 7 or Art. 35 cannot be requested after 5 years from the date of the trademark registration (Art. 122(1)). [1]

Giving consent also affects the right holder of the earlier registered trademark. This is the case where, after the later trademark has been registered, the right holder of the earlier registered trademark seeks to register an identical or similar trademark on identical or similar designated goods. The Trademark Examination Guidelines state that the consent of the right holder of the later trademark is then required. [4]

What applicants should do

• In general, we suggest not filing a coexistence agreement used in another country as it is. If it contains a territorial limit or a time limit, it is treated in Korea as a conditional letter of consent and is not accepted.
• We suggest stating in the letter of consent, case by case, the Korean registration number or application number and the designated goods consented to.
• On receiving a ground for rejection under Art. 34(1), subparagraph 7, we suggest first estimating the schedule of the consent negotiation within the period for submitting a written opinion. The choice between a written opinion disputing similarity, a reduction of the designated goods and a letter of consent depends on that schedule.
• We suggest that the party giving consent first review the fact that its own later applications for similar trademarks will then need the consent of the other party.
• We suggest that both parties set out the manner of use after registration in a separate contract between them. For an individual case, please check with your agent.

FAQ

Can an identical trademark be registered with a letter of consent?

Yes, where the trademark is identical but the designated goods are similar and not identical. Only the case where both the trademark and the designated goods are identical is excluded (parenthetical in the proviso to Art. 34(1), subparagraph 7 of the Trademark Act). [1]

Can a letter of consent be filed for a trademark application filed before 1 May 2024?

Yes, if the decision on whether to grant trademark registration is made on or after that date (Addenda to Act No. 19809, Art. 2). [1]

Can a letter of consent be filed after the period for submitting a written opinion against the notification of grounds for rejection has ended?

For an application with no decision to publish the application, it can be filed attached to a written amendment until the decision to reject trademark registration (Enforcement Rules, Art. 26-2(2), subparagraph 1; Trademark Act, Art. 40(1), subparagraph 2). [1][2]

What happens if the right holder of the earlier registered trademark withdraws the consent?

The Trademark Examination Guidelines do not accept a withdrawal by one party. Before the decision on whether to grant trademark registration, materials on the withdrawal can be filed with a written opinion, a written amendment, a provision of information or the like. After the decision, the trial procedure is followed. [4]

Does the examiner still examine the likelihood of confusion when there is a letter of consent?

When a valid letter of consent is filed, the grounds for rejection under Art. 34(1), subparagraph 7 and Art. 35(1) and (2) are overcome. [4] However, other grounds for rejection, such as subparagraphs 9, 11, 12 and 13, are examined regardless of the consent. [1][4]

How DEFINE IP Law Firm handles this

When a ground for rejection under Art. 34(1), subparagraph 7 is received, DEFINE IP Law Firm first checks whether the case can be resolved with a letter of consent. We check whether both the trademark and the designated goods are identical, and whether any ground for rejection remains apart from the one that consent overcomes. We review the wording of the letter of consent against the required entries in the Trademark Examination Guidelines. For questions about consent to registration for Korean trademark applications, please write to contact@defineip.kr.

Sources

1. Trademark Act (상표법), Act No. 21134, in force from 11 November 2025. Articles 17, 34, 35, 40, 41, 55, 116, 117, 119, 122, 180, 185 and 193-2, Addenda (Act No. 19809, promulgated 31 October 2023, in force from 1 May 2024) Arts. 1 and 2. https://www.law.go.kr/법령/상표법 (verified 9 October 2026)
2. Ministry of Intellectual Property (지식재산처), Enforcement Rules of the Trademark Act (상표법 시행규칙), Prime Ministerial Decree No. 2120, in force from 17 June 2026. Articles 26-2, 33 and 50, Addenda (Ordinance of the Ministry of Trade, Industry and Energy No. 555, 1 May 2024) Art. 2. https://www.law.go.kr/법령/상표법시행규칙 (verified 9 October 2026)
3. Trademark Act (상표법), Act No. 19711, in force from 15 March 2024 (the version before the consent provisions were introduced). Article 34(1), subparagraph 7, and Article 35. Version history at https://www.law.go.kr/법령/상표법 (verified 9 October 2026)
4. Ministry of Intellectual Property (지식재산처), Trademark Examination Guidelines (상표심사기준), MOIP Established Rule No. 5, in force from 10 December 2025. Part 5, Chapter 7, Supplementary Standard 1 “Trademark coexistence consent system” (상표공존동의제도), and Part 4, 1.6.7. https://www.law.go.kr/행정규칙/상표심사기준 (verified 9 October 2026)