Protecting Your Patents in Japan: A Comprehensive Practical Guide

Published on October 31, 2025 and written by Cyril Jarnias

Protecting a patent in Japan, one of the world’s most dynamic innovation environments, requires a thorough understanding of the country’s legal intricacies. This practical guide provides a comprehensive introduction to effective methods for securing your inventions in the Japanese market, detailing crucial steps and nuances to consider when filing a patent application. Covering topics ranging from specific legal requirements to enforcement strategies, this article is designed to be an essential resource for businesses and inventors seeking to establish themselves in an ultra-competitive global arena.

Patent Filing Procedures in Japan

1. Basic Patent Filing Steps

• Preliminary Preparation: Conduct a prior art search to verify that the invention is novel. The search can be performed in databases such as J-PlatPat.
• Document Preparation and Submission: Prepare necessary documents (application form, description, patent claims, abstract, drawings) in accordance with required formats and submit them to the Japan Patent Office (JPO).
• Formality Examination: Verification that submitted documents comply with formal standards.
• Public Examination: The content is made public one year and six months after the filing date.
• Request for Substantive Examination: It’s necessary to request examination within three years of filing. This is where novelty and inventive step, among other criteria, are evaluated.

2. Required Documents

1. Patent Application:
   • Basic information, including names and addresses of the inventor and applicant, are recorded here.
2. Description:
   • Document describing the invention’s content and technical details. It’s important to write concretely and in sufficient detail for an expert in the field to understand.
3. Patent Claims:
   • Concisely and precisely express the portion of the invention to be protected by the patent.
4. Abstract:
   • Brief description of the entire invention. Used for public publication.
5. Drawings (Optional):
   • To explain technical content or structure. However, they’re not always necessary.

3. Fees

Main fees include:

• Filing fee: approximately ¥14,000
• Examination request fee: ¥130,000 or more

*Fees may be reduced for electronic filings. Additionally, fee reduction measures are available for SMEs and individuals.

4. Deadlines and Important Points

Deadlines to meet, with negative consequences for non-compliance:

• 1 year 6 months after filing date: automatic publication
• Examination request deadline: within 3 years of filing date

If appropriate measures aren’t taken within these deadlines, rights protection won’t be possible.

Comparison with Other Countries

Japan (JPO)	United States (USPTO)	Europe (EPO)
First-to-file priority	Same	Same
Substantive examination prerequisites	Examination request required	Automatic
Publication timing	After 18 months	Same
Language	Japanese	English

In Japan, prior art searches are particularly valued, and special attention is required toward provisions such as exceptions to loss of novelty. Conversely, an accelerated examination system is available earlier than in some Western countries.

Common Mistakes and Tips

Common Errors

• Correction orders due to incomplete documents
• Rejection notices received due to insufficient description

Tips

• Recommended consultation with patent attorneys: quality improvement through expert assistance
• Promotion of electronic submissions: cost reduction and efficiency improvement

Understanding Protection for Your Invention

The process of protecting inventions in Japan is conducted through the patent system. Below, I detail the process of obtaining a patent from the Japan Patent Office (JPO), different types of patents, their legal effects and rights, costs, as well as measures in case of infringement.

1. Patent Acquisition Process

• Application Preparation and Submission: To obtain a patent, prepare an “application form,” “description,” “patent claims,” “abstract,” and necessary drawings, then submit them to the Japan Patent Office. Applications can be made by mail or electronically.
• Formality Examination: Verification that submitted documents meet formal requirements.
• Request for Substantive Examination: An examination request must be made within three years of the filing date. This procedure verifies novelty, inventive step, etc.
• Registration and Publication: After passing examination, payment of required fees enables registration and rights grant. In principle, content is published 18 months after the filing date.

2. Different Types of Patents

• Standard Patents (Inventions): Applied to creations resulting from advanced technical thinking, requiring novelty, inventive step, and industrial applicability.
• Design Registration (Design Patent): System for protecting product designs, such as shape, pattern, and aesthetics.
• Utility Model Registration: Applicable to minor improvements or product ideas, mainly targeting “simple technologies.” Different options exist depending on usage and technological level.

3. Methods to Ensure Invention Novelty

To avoid competition with others and maintain novelty, it’s recommended to:

• Use prior art search tools (e.g., J-PlatPat)
• Prevent information leaks before publication

If overlapping with existing technologies, a new application may be refused.

4. Legal Effects and Rights

Valid only in Japan, but includes strong protection functions, such as:

• Injunction against use by others
• Financial remedies such as damages/profit compensation

Cost Overview

Items	Example Cost
Filing fee	¥14,000
Examination fee	¥138,000 + (¥4,000 per claim)
First year registration fee	Approx. ¥4,300 + amount for each additional claim

A fee reduction system is also available

Intellectual Property: Japanese Specificities

The Japanese patent system has unique characteristics that are important points regarding patent protection and impact on foreign companies. Here’s an explanation of differences between Japan and other countries, along with practical recommendations.

1. First-to-File System and Filing Procedure

• Japan has adopted a first-to-file system, where the first to file for the same or similar invention can obtain patent rights.
• When filing, the invention content must be described in detail, and this content is made public after one year and six months.
• Other countries (like the United States) previously used a first-to-invent system, but currently, the US also applies the first-to-file system like Japan. However, differences exist in implementation methods.

2. Patent Examination Process

• In Japan, an examination request must be made within three years of filing. During the examination period, criteria such as novelty, inventive step, and industrial applicability are verified.
• The examination process averages about 10 months, but it often takes several years to obtain a result. In other countries too, patent examination durations tend to lengthen, but in Japan, efforts are made to improve this process’s efficiency.

3. Patent Rights Validity Period

• In Japan, obtained patent rights are valid for 20 years from the filing date. For pharmaceutical products, for example, exceptions allow extensions up to 5 years.
• In this regard, there’s no major difference with Western countries. However, even during the validity period, payment of maintenance fees (annual fees) is necessary. This system is also common to most major jurisdictions.

4. Translation Issues

When submitting applications to Japan by foreign companies, it’s essential to provide accurate translation documents. However, errors or incomplete translations can lead to rejection reasons. Therefore, it’s important to strengthen the use of high-quality specialized translation services and collaboration with local patent agents.

5. Challenges for Foreign Companies and Territoriality Principle

For foreign companies, it’s essential to understand protection criteria and infringement judgment according to national legal standards for products targeting the Japanese market. Additionally, under Japanese law, the territoriality principle imposes limits on the possibility of direct lawsuits against foreign companies.

Practical Recommendations:

1. Quick Response: Quickly engage the filing process and establish a priority management system based on the first-to-file system.
2. Translation Accuracy: Strengthen the document creation and verification process with local translators or agents having specialized expertise.
3. Expert Utilization: Build collaboration with intellectual property experts such as patent attorneys to address Japan’s specific rules.
4. Long-term Strategy: Develop a maintenance fee payment plan and adjust new product development cycles.

Understanding these points and implementing measures can improve success in entering the Japanese market.