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Letter of Consent in Japan: Practice After the 2024 Amendment

Picture of Takefumi Sugiura – Japanese Patent Attorney

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Effective April 1, 2024, the Japan Trademark Act introduced a Letter of Consent (LoC) system under Article 4(4), bringing Japan in line with most major jurisdictions. This article explains how the LoC works in practice, what the JPO requires for acceptance, and how foreign counsel can leverage the new system to overcome Article 4(1)(11) refusals.

1. What Changed in April 2024

Before April 2024, a written consent from a prior right holder was not a basis to overcome an Article 4(1)(11) prior mark refusal in Japan. Foreign counsel were often surprised — and frustrated — that consent that worked in their home jurisdiction had no effect at the JPO.

The 2024 amendment introduced Article 4(4), which provides that Article 4(1)(11) does not apply where:

  1. The applicant has obtained the prior right holder's consent, AND
  2. There is no likelihood of source confusion between the two marks

Critical nuance: Japan's LoC is not a "true" consent regime. The consent alone is insufficient. The applicant must also demonstrate to the JPO that no source confusion will result.

2. JPO Acceptance Criteria

In examining a LoC submission, the JPO considers:

  • Distinctiveness of the marks: Highly distinctive marks support coexistence more easily
  • Trade channels: Different distribution channels reduce confusion
  • Geographic scope: Distinct geographic territories support coexistence
  • Customer base: Different consumer demographics or industries
  • Use history: Prior coexistence without confusion in Japan or other jurisdictions
  • Protective measures: Disclaimers, distinguishing marketing, separate logo elements

A bare consent ("we agree to your registration") will not succeed. The submission must build a fact-based case that confusion is unlikely.

3. What an Effective Letter of Consent Includes

EVORIX's standard LoC includes the following components:

  1. Identification: Both parties (legal entity, address, role)
  2. Mark details: Both marks, registration/application numbers, goods/services
  3. Express consent: Prior right holder's unconditional consent to the new application
  4. Non-confusion factual basis: Detailed explanation of why no source confusion will result
  5. Coexistence terms (optional): Practical arrangements (e.g., different logo styles, separate marketing channels, disclaimer language)
  6. Signatures: Authorized signatories of both parties, with dates

Submitted to the JPO with a Japanese translation if executed in another language. We provide a Japanese translation as part of the engagement.

4. Coordinating with the Prior Right Holder

Foreign counsel may not have direct contact with the Japanese prior right holder. EVORIX handles outreach in three modes:

Mode When Used
Direct outreach Prior right holder is a Japanese company or individual without foreign counsel
Foreign-counsel coordination Prior right holder is foreign with overseas counsel — we coordinate via your firm
Anonymous initial contact Where the applicant prefers not to disclose identity initially (subject to ethics rules)

5. Typical Cost and Timeline

EVORIX's LoC service typically costs JPY 80,000 – 150,000 for drafting and filing. This includes:

  • Strategy consultation and feasibility assessment
  • LoC drafting in Japanese and English
  • Up to two rounds of revisions per party
  • Coordination with prior right holder (mode varies)
  • Filing with the JPO and follow-up communication

Timeline depends on counterparty cooperation. Cooperative counterparties resolve in 2-4 weeks; uncooperative or hesitant ones may require 2-3 months. We typically request a JPO response deadline extension to allow time for coordination.

6. Strategic Considerations

Use the LoC route when:

  • The cited mark's owner is identifiable and reachable
  • Marks share clear distinguishing factors (logos, channels, geography)
  • No business conflict exists or can be resolved commercially
  • Pure dissimilarity arguments are weak

Avoid the LoC route when:

  • The prior right holder is a direct competitor with active commercial conflict
  • The marks are essentially identical with overlapping markets
  • The prior right holder has signaled enforcement intent
  • Time pressure is severe and counterparty is unresponsive

Frequently Asked Questions

Will any consent letter work, or does it need to be in a specific form?
There is no statutory form, but the consent must be in writing, dated, and signed by an authorized representative of the prior right holder. Consent expressed in emails, settlement agreements, or coexistence agreements may also qualify if the consent is unambiguous.
Can the LoC be revoked after it is given?
Once filed and relied upon by the JPO to grant registration, the consent is generally not revocable in a way that affects the registration. However, prior right holders may attempt to invalidate the registration on other grounds, so robust documentation of the consent transaction is important.
Is there any case law on Article 4(4) yet?
As of late 2026, JPO examination practice is still developing. Examiners are accepting LoC submissions in the majority of well-supported cases. Trial Board and IP High Court decisions are emerging gradually. We monitor practice developments and incorporate them into our drafting.

FOR FOREIGN COUNSEL

Need to respond to a JPO Provisional Refusal?

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