From Filing to Grant: The Complete Patent Prosecution Process in Japan and the US

Obtaining a patent is not a single act but a multi-stage administrative process that typically spans one to five years. Understanding each step—from the initial filing to the issuance of a patent certificate—is essential for anyone managing a patent portfolio, planning a technology launch, or evaluating freedom to operate. This article traces the full prosecution path under Japanese law and compares it with US and European practice.

Step 1: Filing the Application

A patent application in Japan is filed with the Japan Patent Office (JPO) and must include: (1) the written request, (2) the specification (detailed description of the invention), (3) the claims (scope of protection), (4) the abstract, and (5) drawings where necessary (Patent Act, Article 36). The filing date—the date the complete application is received by the JPO—becomes the priority date: it determines the cutoff for prior art in novelty and inventive step analysis, and it starts the 20-year patent term.

Government filing fees are assessed per claim. Under JPO’s fee schedule for 2024, the basic filing fee is ¥14,000 plus ¥1,700 per claim. A typical 10-claim application therefore incurs a government fee of approximately ¥31,000 (~USD 200). Patent attorney fees for drafting and filing add substantially to this—generally ¥200,000–¥500,000 in Japan depending on complexity.

Applicants may claim priority under the Paris Convention (1883) by filing foreign applications within 12 months of the first (priority) filing. This allows inventors to assess commercial prospects during the 12-month window before committing to the expense of multi-country filing.

Step 2: Publication—Compulsory Disclosure at 18 Months

Under Japan’s publication system (Patent Act, Article 64), every pending application is published in the official Patent Gazette 18 months after the filing date (or priority date). This publication serves the patent system’s core disclosure function—making technical information available to the public even before a patent is granted.

From the date of publication, the applicant acquires a “right to claim compensation” (Article 65): if a third party commercially exploits the published invention before the patent is granted, the patentee may claim a monetary amount equivalent to a reasonable royalty after grant. This right attaches retroactively to pre-grant infringement, giving the applicant a form of interim protection.

Early publication (before the 18-month default) can be requested where speed of disclosure is strategically important—for instance, to establish prior art against competitors’ overlapping applications. Conversely, withdrawing an application before publication prevents disclosure entirely.

Step 3: Examination Request—A Three-Year Window

Japan operates a deferred examination system: substantive examination does not begin automatically upon filing. The applicant must file a separate “Request for Examination” within three years of the filing date; failure to do so results in the application being deemed withdrawn (Patent Act, Article 48-3).

This deferred system allows applicants to evaluate commercial viability and competitor activity before investing in examination. The examination request fee scales with the number of claims: ¥138,000 base fee plus ¥4,000 per claim (2024 schedule). For a 10-claim application, the total examination request fee is approximately ¥178,000.

The Early Examination system (Article 48-6) allows expedited processing for applications that meet certain criteria—such as commercialization of the invention, relevance to national policy priorities, or eligibility under the Patent Prosecution Highway (PPH) with a partner office. Under the PPH, a positive examination result from one participating office can accelerate examination at another.

Step 4: Substantive Examination

Once examination begins, the JPO examiner conducts a prior art search covering domestic and foreign patent documents and non-patent literature (scientific publications, product manuals, websites). The examiner evaluates the application against the requirements of novelty (Article 29(1)), inventive step (Article 29(2)), industrial applicability (Article 29(1) preamble), and disclosure adequacy (Article 36).

According to JPO statistics for FY2023, the average time from examination request to the first examination result (Office Action or allowance) was approximately 9.5 months across all technology fields. Biotechnology and information communications fields—which receive high application volumes—tend to have longer wait times.

Step 5: Office Action (Notice of Reasons for Refusal)

If the examiner identifies deficiencies, a Notice of Reasons for Refusal (拒絶理由通知) is issued under Article 50. This document identifies the specific legal grounds for rejection—most commonly lack of novelty, lack of inventive step, or inadequate disclosure—and cites the relevant prior art references.

The applicant has a set response period, typically 60 days from the dispatch date (extendable by request), to submit a response comprising a written argument (opinion letter) and/or an amendment to the claims or specification. The written argument challenges the examiner’s legal and technical reasoning; the amendment narrows the claims to distinguish the invention from cited prior art.

Amendments are subject to the prohibition on adding “new matter”—any amendment must remain within the scope of the originally filed disclosure (Article 17-2(3)). This requirement, common to all major patent systems, prevents applicants from expanding their original invention through post-filing amendments.

Step 6: Grant or Final Rejection

After reviewing the applicant’s response, the examiner either issues a Notice of Allowance (登録査定) or a Final Rejection (拒絶査定). If allowed, the applicant must pay the registration fee within 30 days to effectuate the patent (Article 66). The first three years of maintenance fees are ¥6,300 plus ¥500 per claim; annual renewal fees escalate over the patent term.

If a second Office Action is issued and the applicant’s second response does not resolve the examiner’s objections, a Final Rejection follows. In some cases, examiners issue only one Office Action before a Final Rejection; in others, multiple rounds of exchange occur.

Step 7: Appeal—Board of Appeal and IP High Court

A finally rejected applicant may file an Appeal against the Examiner’s Decision of Refusal (拒絶査定不服審判) with the JPO’s Board of Appeal within three months of the final rejection (Article 121). The Board, consisting of three or five appeal examiners, conducts an independent review and may allow the application, confirm the rejection, or remand it to the examiner. Additional claim amendments may be submitted with the appeal. Average appeal pendency is approximately 14 months (FY2023).

If the Board affirms the rejection, the applicant may file an action to revoke the appeal decision (審決取消訴訟) before the Intellectual Property High Court (IP High Court) within 30 days (Article 178). The IP High Court, established in 2005 as a specialized IP tribunal, hears these cases before a panel of technical judges who may obtain expert opinions. Decisions of the IP High Court may be further appealed to the Supreme Court, though such appeals are rarely accepted.

US and European Comparison

In the United States, substantive examination begins automatically upon filing—no examination request is required. The average total pendency (filing to grant) at the USPTO has historically been around 25–30 months, though Track 1 Prioritized Examination reduces this to approximately 6–12 months for an additional fee (~USD 4,000 for large entities). Post-grant, third parties may challenge patents through Inter Partes Review (IPR) or Post-Grant Review (PGR) before the Patent Trial and Appeal Board (PTAB), which has become an active venue for challenging patent validity since the America Invents Act (AIA, 2011).

At the European Patent Office (EPO), examination is also substantially automatic. A single EPO application, if granted, can be validated in any of the 39 member states. The new Unitary Patent system, which launched in June 2023, allows a single post-grant request to provide unitary protection in up to 17 participating EU states—streamlining what previously required separate national validation in each country. EPO opposition proceedings, available within nine months of grant, allow third parties to challenge European patents before the EPO itself.

The next article in this series examines the patent claims—the legal text that defines the scope of the patent right and determines whether a product or process infringes.