• last updated : 26 February, 2024

Insider’s Guide: Crucial Points for Filing Patents in Japan

Category: Blog
Crucial Points for Filing Patents in Japan

Japan is among the top three countries in the world for patent applications, only surpassed by China and the US. Just 19% of the more than 300,000 applications that the Japan Patent Office (JPO) received in 2018 were submitted by non-residents.

This disparity highlights the difficulties faced by foreign applicants wishing to file in Japan, as they may encounter difficulties with patent translations in addition to expensive filing fees.


As one of the world’s leading hubs for innovation and technology, Japan offers a promising landscape for inventors and businesses seeking to protect their intellectual property through patents.

However, navigating the patent filing process in Japan requires careful consideration of various factors to ensure a smooth and successful application.

In this blog, we’ll explore 11 key considerations to keep in mind when filing a patent in Japan.

1. Understanding Japan’s Patent System

Before delving into the patent filing process, it’s essential to familiarize yourself with Japan’s patent system. Japan operates under a first-to-file system, meaning that the first inventor or applicant to file a patent application is typically granted priority rights.

Additionally, Japan is a member of the Patent Cooperation Treaty (PCT), allowing applicants to streamline the international patent application process.

2. Conducting Prior Art Search

As with any patent application, conducting a thorough prior art search is crucial to assess the novelty and patentability of your invention.

Identifying existing patents, technical literature, and other relevant materials will help you gauge the uniqueness of your invention and refine your patent application accordingly.

3. Language Requirements

Japanese is the official language of patent filings in Japan. While it’s possible to submit patent documents in English, applicants are required to provide a Japanese translation of the specification and claims within a designated timeframe.

Working with a qualified patent translator or attorney proficient in Japanese is essential to ensure accurate and compliant translations.

4. Hiring a Local Agent

To navigate Japan’s patent system effectively, it’s advisable to engage the services of a local patent agent or attorney with expertise in Japanese patent law. A qualified agent can provide valuable insights, assist with documentation, and represent you before the Japan Patent Office (JPO) throughout the application process.

5. Filing Strategy

Developing a comprehensive filing strategy is essential for maximizing the protection and value of your patent in Japan.

Consider factors such as the scope of protection, potential competitors, and long-term business objectives when drafting your patent application and selecting appropriate filing routes.

6. Patent Examination Process

Upon filing your patent application with the JPO, it undergoes a rigorous examination process to assess its novelty, inventive step, and industrial applicability.

The examination process typically involves multiple rounds of review and may require responding to office actions or objections raised by patent examiners.

7. Patentability Criteria

In Japan, patents are granted for inventions that are novel, involve an inventive step, and are industrially applicable. Ensuring that your invention meets these patentability criteria is essential for a successful application.

Conducting a thorough patentability assessment and consulting with a patent professional can help strengthen your application.

8. Patent Term Extensions

In certain cases, it may be possible to extend the term of your patent in Japan through supplementary protection certificates (SPCs) or patent term extensions (PTEs).

In Japan, Supplementary Protection Certificates (SPCs) or Patent Term Extensions (PTEs) are critical tools for compensating patent holders for the time lost during the regulatory approval process of pharmaceuticals and agricultural chemicals.

By extending the life of a patent beyond its original term, SPCs/PTEs ensure that inventors can adequately recoup their investment in research and development. The Japanese Patent Office (JPO) administers these extensions, which can significantly impact the commercial viability and profitability of patented innovations in these sectors.

This mechanism is designed to balance the need for stimulating innovation and the public’s access to drugs and agricultural products, reflecting the country’s commitment to supporting advancements in science and technology while ensuring public health and food security.

These mechanisms are available for pharmaceutical and agrochemical products that undergo regulatory review processes, allowing patentees to recover lost patent term due to regulatory delays.

9. Patent Enforcement and Litigation

Understanding the process of patent enforcement and litigation in Japan is crucial for protecting your patent rights against infringement. Japan’s legal system provides robust mechanisms for enforcing patents through civil litigation and administrative proceedings.

Engaging experienced intellectual property litigators can help you navigate potential disputes effectively.

10. Patent Prosecution Costs

The costs associated with prosecuting a patent application in Japan can vary depending on various factors, including the complexity of the invention, the extent of prior art, and the duration of the examination process. Budgeting for patent prosecution costs and seeking cost-effective strategies can help manage expenses while ensuring comprehensive patent protection.

11. Patent Maintenance and Renewal

Once your patent is granted in Japan, it’s essential to stay informed about maintenance and renewal requirements to keep your patent in force.

Maintenance fees are payable at regular intervals throughout the patent term, and failure to pay these fees can result in the expiration of your patent rights.

How XLSCOUT’s Novelty Checker LLM Helps in Conducting Prior Art Searches?

The Novelty Checker LLM makes prior art searches easier for inventors. The tool searches for similar inventions to yours to determine whether a patent is feasible.

XLSCOUT leverages ParaEmbed model in its AI-based prior art search tool, Novelty Checker, to get quality prior art search reports within few minutes. The Novelty Checker uses reinforcement learning to filter the noise by showing the relevant results on top of the list.

To be precise, it assists in conducting patentability search to help you ensure that your innovation is unique. By selecting a few relevant and non-relevant results, users can apply them to the result set.

The system takes the user’s feedback and then learns from it. It uses conceptual searching and re-ranks the results by bringing the quality results to the top and sending the noise to the bottom.

Drafting Precise and Comprehensive Patent Applications in Japanese with Drafting LLM

XLSCOUT’s Drafting LLM, an innovative AI patent drafting tool, utilizes cutting-edge technologies such as Large Language Models (LLMs) and Generative AI to swiftly generate preliminary patent drafts.

This module not only crafts detailed claims, abstracts, backgrounds, descriptions, and drawings (including flowcharts and block diagrams) but also excels in creating a concise description of these drawings, all within minutes.

A standout feature of this automated patent drafting tool is its ability to draft patent applications compliant with Japanese jurisdiction, showcasing its versatility. Additionally, the AI patent drafting module is enhanced with an AI chatbot, offering real-time, iterative refinements to the patent draft, ensuring that the final product is polished and precisely tailored to the user’s needs.

This integration of AI technologies significantly streamlines the patent drafting process, making it more efficient and accessible.


In conclusion, filing a patent in Japan offers exciting opportunities for protecting and commercializing your inventions in a thriving innovation ecosystem. By considering these 11 key factors and working closely with experienced patent professionals, you can navigate the patent filing process in Japan with confidence and maximize the value of your intellectual property assets in one of the world’s most dynamic markets.

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