PCT National Phase in Japan: The Essential 30-Month Guide

A PCT application buys you time, not a patent. It holds your filing date across most of the world while you decide where protection is worth the spend, but it never becomes an enforceable Japanese right on its own. To turn that option into a real patent you have to leave the international system and enter the country, and the PCT national phase in Japan is where that happens. Japan is not part of the European system, so there is no validation shortcut — you enter the JPO directly. Two separate clocks govern the process, and applicants who watch only one of them lose rights they thought were safe.

How the PCT National Phase in Japan Works

Your PCT application went through an international phase — an international search, perhaps a preliminary examination, and publication by WIPO. None of that grants a patent anywhere. A PCT application is a placeholder that holds your filing date in over 150 states while you decide where protection actually earns its keep. Every national deadline still runs from your original priority date.

Entering the PCT national phase in Japan converts that reservation into a live Japanese application before the Japan Patent Office (JPO). Because Japan is not a member of the European Patent Convention, there is no European validation route into the country: you cannot reach Japan by validating a European patent. You enter the JPO directly, whether from a PCT application or by a direct Paris Convention filing.

If you are mapping your overall route into the country, read this alongside our guide on how to file a patent in Japan, which compares the PCT and direct options at a higher level.

The 30-Month Deadline — Stricter Than Europe’s

Japan’s national-phase deadline is 30 months from the priority date — a month tighter than the 31 months many European offices allow, and a difference that quietly catches out teams docketing everything to a single global date. If your PCT application claimed no priority, the clock runs 30 months from the international filing date.

Treat it as a hard wall. Japan does allow national-phase entry after the 30-month period in limited cases where the delay was unintentional and the prescribed procedure and fees are met, but this relief is narrow, discretionary and expensive, and it should never form part of a filing plan. In practice, missing 30 months ends the Japanese route for that invention.

The takeaway is simple: dock Japan separately at 30 months the moment you file the PCT application, and never assume it shares the deadline you use for your European targets.

The Japanese Translation You Must File

Unless your PCT application was filed in Japanese, entry requires a Japanese translation of the description, claims, abstract and any text in the drawings. As a rule, that translation is due within the 30-month period along with the national document.

The JPO builds in a modest cushion. If you file the national document (the request to enter, on the JPO’s Form 53) during the last two months before the 30-month date, you may file the Japanese translation within two months of that national document — which can push the translation slightly past the 30-month mark. It is a safety valve, not a strategy: budget the translation early, because a poor or rushed rendering narrows the claims you can later enforce. The Japanese text, not your original, defines the granted right.

Because claim scope in Japan is read strictly from the Japanese wording, a specialist translator who understands your technology is worth far more than the cost saved by a generic one. This is not a place to economise.

The Second Clock: Request Examination Within Three Years

Here is the trap that surprises the most applicants. Entering the national phase does not put your application into examination. In Japan, examination happens only if you file a request for examination, and that request must be made within three years of the international filing date — not three years from national-phase entry, and not from the priority date.

For a PCT application that entered at 30 months, the three-year window can be close, so the two clocks — 30 months to enter, three years from filing to request examination — need docketing side by side from day one. Miss the examination request and the application is deemed withdrawn; there is no ordinary way to revive it. If no request is filed by anyone, the case simply dies.

Requesting examination is also where the largest official fee falls due, so it doubles as a natural decision point: it is the moment to confirm Japan still justifies the investment before you commit to substantive prosecution.

JPO Fees for 2026

Two official fees dominate the budget. The JPO filing fee for national-phase entry is around JPY 14,000 (about JPY 22,000 where the application is filed in a foreign language). The far larger cost is the request for examination, at roughly JPY 138,000 plus about JPY 4,000 per claim, which is why claim count materially affects your Japanese budget and why trimming redundant claims before you request examination pays off directly.

Annual renewal fees then keep the application and granted patent alive, rising in steps over the patent’s twenty-year term. These figures move periodically, so confirm the current schedule on the JPO’s own site before you pay, and note that professional translation and local-agent costs usually exceed the official fees themselves.

For a broader view of how the international application is assembled before any of this, see our guide on filing a PCT international patent application. Drawings that meet JPO formalities matter too — our overview of patent drawings in Japan covers the specifics.

After Grant: Where You Enforce a Japanese Patent

Japanese patent infringement is litigated at first instance before two specialised venues: the Tokyo District Court and the Osaka District Court, which hold exclusive jurisdiction split roughly by the defendant’s location in eastern or western Japan. Appeals go to the Intellectual Property High Court in Tokyo, a dedicated IP appellate court whose decisions shape national practice.

Validity can be challenged either through an invalidation trial at the JPO or as a defence in the infringement suit, and the courts and the JPO coordinate closely. Injunctions are available and damages are calculated under statutory formulas, but discovery is limited compared with the US, so building your evidence early matters. None of this is reachable through the European systems — there is no UPC dimension to a Japanese patent, only the Japanese courts.

The practical lesson is that national-phase entry is the first move in a litigation strategy you will execute years later. Choose Japan deliberately, translate it well, and docket both clocks — the market rewards applicants who treat entry as more than a formality.

How PerspireIP Can Help

PerspireIP dockets both your 30-month entry deadline and the three-year examination clock, coordinates specialist Japanese translation, and manages the JPO national phase from entry through grant. Explore our Japan IP hub and our teams in Tokyo and Osaka, then contact us well before the clock runs out.

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