"We received a Notice of Reasons for Refusal from the JPO. How long do we have?" "The examiner says our claims are unclear, but they were fine in China." "We just found a translation error in the Japanese text — can it be fixed?"
Most Japanese patent applications receive at least one Office Action — in Japan called a Notice of Reasons for Refusal. It is not a final rejection: with well-reasoned arguments and amendments, many applications go on to grant. But when your Japanese application is a translation of an English or Chinese specification, there are extra points to watch. In this article, Japanese Patent Attorney Toru Kano of BrandAgent explains how to respond, covering deadlines for overseas applicants, amendment limits and the correction of mistranslations.
*Information as of November 2026. Official fees are listed in the JPO schedule of fees.
What you will learn
- How translated applications work in Japan (foreign-language filings and PCT national phase)
- The most common grounds for refusal
- Response deadlines and extensions for overseas applicants
- Limits on amendments, including after a "final" notice
- Correcting mistranslations — procedure and official fee
Responses must be filed through a Japanese patent attorney
An applicant with no domicile or business office in Japan cannot respond to the JPO directly. Arguments, amendments, extension requests and appeals are filed through a representative in Japan — a licensed Japanese patent attorney (Benrishi). At BrandAgent, every case is handled personally by the patent attorney; we report Office Actions with an English or Chinese explanation and a recommended strategy, and payment can be made by PayPal (in JPY) or bank transfer.
Translated applications: foreign-language filings and PCT national phase
Japan allows a foreign-language application: you file the specification in English (or another language) and submit the Japanese translation later. The translation is due within 1 year and 4 months of the filing date — or of the earliest priority date if priority is claimed. If it is missing, the JPO sends a notice and allows 2 more months; after that, the application is deemed withdrawn. For a PCT application, the Japanese translation is filed on entering the national phase, within 30 months of the priority date.
In both cases, the JPO examines the Japanese translation. For a foreign-language application, the translation is deemed to be the description, claims and drawings as filed. In other words, the quality of the translation is the quality of your patent.
Common grounds for refusal
| Ground | What it means |
|---|---|
| Novelty (Art. 29(1)) | The same invention was publicly known before filing. |
| Inventive step (Art. 29(2)) | A person skilled in the art could easily have made the invention from the prior art. The most common ground. |
| Clarity (Art. 36(6)(ii)) | The claims are unclear — often caused by literal translation or inconsistent terminology. |
| Support (Art. 36(6)(i)) | The claimed invention goes beyond what the description discloses. |
| Enablement (Art. 36(4)(i)) | The description does not allow a skilled person to carry out the invention. |
| Matter beyond the original text (Art. 49(vi)) | In a foreign-language application, the Japanese text contains matter not described in the original foreign-language document. |
Clarity objections are especially frequent for translated applications. A Chinese claim translated word for word into one very long Japanese sentence, or a component given two different Japanese terms, can easily be judged unclear — even if the claim passed examination in China. Different offices apply different standards, so an allowance abroad is useful evidence but not a guarantee.
Response deadlines and extensions for overseas applicants
The response period set in a Notice of Reasons for Refusal is 60 days for domestic residents and 3 months for overseas applicants. For notices issued during examination of a patent application, the JPO allows the following extensions (practice since 1 April 2016):
| Extension | Overseas applicants | Official fee |
|---|---|---|
| Requested within the period | 1st request: 2 months; 2nd request: 1 more month (max. 3 months) | JPY 2,100 per request |
| Requested after the period expired | 2 months, if requested within 2 months after expiry | JPY 51,000 |
No reason is needed for an extension, and the two in-period requests can be filed at the same time. A late extension request is not available if an in-period extension was already granted or if you already responded within the original period. These rules do not apply to notices issued after an appeal against a decision of refusal has been filed.
With translation into and out of Japanese and internal review on your side, 3 months goes quickly. We recommend deciding early whether to extend — the in-period extension is far cheaper than the late one.
How to respond: arguments and amendments
- Written opinion (arguments): rebut the examiner's findings and explain the differences from the cited references and the advantageous effects of the invention.
- Amendment: narrow the claims or fix unclear wording.
Filing arguments and an ordinary amendment carries no official fee. For inventive step, the key is to attack the logic of combining the references and to show the invention's effects. If the same invention is being examined in China, the US or Europe, the amendments and reasoning there are valuable input. Interviews with the examiner (including online) are also possible through your Japanese attorney.
Limits on amendments
Main restrictions on amendments
- No new matter (Art. 17-2(3)): amendments cannot go beyond the description, claims and drawings as filed. For a translated application, an ordinary amendment must stay within the Japanese translation.
- No "shift" amendments (Art. 17-2(4)): after a Notice of Reasons for Refusal, you cannot switch the claims to a different invention that lacks unity with the invention already examined.
- After a final notice (Art. 17-2(5)): claim amendments are limited to (1) deleting claims, (2) restrictively narrowing the claims, (3) correcting clerical errors, and (4) clarifying unclear statements pointed out in the notice.
A "final" Notice of Reasons for Refusal basically notifies only reasons that became necessary because of the amendments made in response to the first notice. Because your options shrink at that stage, it pays to make well-planned amendments in the first response. A divisional application can also be considered while you are still able to amend.
Correcting a mistranslation
Sometimes the Office Action reveals that the Japanese text does not match the original — for example, "at least one" translated as "one", or a term rendered more narrowly than in the original. To fix such errors, you file a statement of correction of mistranslation instead of an ordinary amendment.
Correction of mistranslation — key rules
- It allows amendments beyond the Japanese translation, as long as they stay within the original text (the foreign-language document, or the international application as filed).
- The reasons for the correction must be stated.
- It can be filed at the same times as ordinary amendments.
- Official fee: JPY 19,000.
- Ordinary amendments made at the same time can be included in the same statement.
Matter that is not in the original text cannot be added at all, and for a foreign-language application, matter beyond the original document is itself a ground for refusal. When you receive an Office Action, we recommend checking the Japanese translation against the original at the same time as preparing arguments. Sometimes the wording you need as a basis for an amendment was lost in translation — and a mistranslation correction can bring it back.
If the application is finally refused
If the reasons for refusal are not overcome, the examiner issues a decision of refusal. You can file an appeal within 3 months of service of the decision; for patent applications of overseas applicants, the JPO extends this by 1 month ex officio, giving about 4 months in total. Claims can be amended at the same time as the appeal is filed (within the four purposes listed above).
FAQ
- Q. How long do we have to respond?
A. 3 months for overseas applicants, extendable by up to 3 months with in-period requests (JPY 2,100 each). - Q. We missed the deadline. Is it too late?
A. If no more than 2 months have passed, a late extension request (JPY 51,000) may give you 2 more months — unless an extension was already granted. - Q. Can we fix a translation error?
A. Yes, within the scope of the original text, by a correction of mistranslation (official fee JPY 19,000), filed when amendments are allowed. - Q. Do arguments cost an official fee?
A. No. Arguments and ordinary amendments have no official fee; attorney fees depend on the case — ask us for a free quote. - Q. Can we communicate in English or Chinese?
A. Yes. Every case is handled personally by a licensed Japanese patent attorney, in English and Chinese.
Key points
- The JPO examines the Japanese translation, so translation quality equals patent quality.
- Overseas applicants have 3 months to respond, extendable by up to 3 months.
- Watch the limits: no new matter, no shift amendments, restricted purposes after a final notice.
- Translation errors can be corrected within the original text (JPY 19,000).
- Check the translation against the original whenever an Office Action arrives.
Related articles
- Patent Prosecution Highway (PPH) in Japan: Speed Up Examination with CNIPA and Other Office Results
- How to Get a Patent in Japan as a Foreign Applicant: Documents, Routes and Process
- How Much Does a Japanese Patent Cost? Official JPO Fees for Foreign Applicants (2026)
- Japanese Patent Annuities (2026): How to Pay, Late Payment and Restoration of a Lapsed Patent
Received a Japanese Office Action?
Send us the notice and your application number — we will review the reasons for refusal, check the translation against the original, and reply with a strategy and a quote, free of charge.
BrandAgent Patent Office (Kyoto, Japan)
Toru Kano, Japanese Patent Attorney