Patent application should be filed through "PCT Route" or "Paris Route" in Japan?

April 03, 2013
Most of foreign applicants file a patent application in Japan through “PCT Route” as a national phase application or “Paris Route” as a priority application.  Which routes should be chosen in a comprehensive manner?  We pick up advantages and disadvantages of the two routes in terms of Cost, Time Restriction and Flexibility.

1. Cost

A) Filing Fee
The cost for filing fee in Paris Route and entering fee in PCT Route are same at 15,000 JPY.
However, additional filing fee is needed in PCT Route at the timing of filing PCT application (about 1,400 USD in US case).
B) Examination Fee
The cost for examination fee of PCT Route is a little lower than that of Paris Route.
PCT Route : 106,000 + 3,600 per claim (JPY)
Paris Route : 118,000 + 4,000 per claim (JPY)
C) Other Costs
Other costs, such as a registration fee and an annual fee, are same in both routes.

2. Time Restriction

As you well know, the time restriction on the timing of filing (entering) an application are different between two routes.

A) PCT Route
You have enough time (30 months after filing date of a PCT application) to decide whether a PCT application should be entered into the national phase in Japan.  You are also given time to file a Japanese translation up to 32 months after filing a PCT application.  Thus, you can carefully review and sort out PCT applications before entering into the national phase in Japan.

B) Paris Route
In contrast, Paris Route obliges you to file a JP application within one year after filing an original application (a priority application) in your country.  Of course, you need to prepare an application document in Japanese (Japanese document) before filing.
However, if you utilize the foreign language application system (*1), you can submit the Japanese translation within one year and two months from the original application.
(*1) The foreign language application system allows you to tentatively file a JP application in English (English document), and then, to file a Japanese translation of the English document.

3. Flexibility

A) PCT Route
Although a literal Japanese translation of PCT application is generally filed, the perfect correspondence between the Japanese translation and a PCT application is not required in Japan.  According to the Examination Guidelines, a Japanese translation is allowed as far as it is obvious from the original disclosure in PCT application.  In other words, it is not necessary to file a “Mirror Translation” of a PCT application which is required in other countries such as USA.
If a Japanese translation is beyond the scope of a PCT application, an office action to reject the national phase application in Japan may be issued.  However, you can overcome the rejection by amending the Japanese translation to fall into the scope the PCT application.  This means you can make up for a substantive mistake in the Japanese translation.

B) Paris Route
Paris Route does not require the perfect correspondence between a JP application and an original application.  Thus, a JP application can be a modified or revised version of the original application to conform to JP practice, as far as the indenticalness of inventions between the JP application and the oringinal appliaction sustains.
However, if there is discrepancy between the Japanese document of the JP application and the original application, an amendment to conform the Japanese document to the original application might not be allowed.  This is because an amendment should be supported by a JP application (i.e., the Japanese document) not by the original application.  This means you may be unable to make up for a substantive mistake in the Japanese document, which results in loosing the benefit of priority of the original application.


Generally speaking, PCT Route gives an applicant enough time before entering into a national phase, while Paris Route is a cost saving way and convenient (flexible) for an applicant.

However, as mentioned above, PCT Route is not so strict about the translation, which makes PCT Route more useful for an applicant.  Thus, the usability of PCT Route is better than that in other countries such as USA, so you need not hesitate to utilize PCT Route.  Especially, PCT Route is thought to be best way when you seek for a patent protection in many countries including Japan.

Paris Route would be a reasonable option when you consider filing an application in a few countries including Japan.  In this case, we would recommend that you choose the foreign application system since it gives you a little more time for preparing Japanese translation.  Besides, utilizing the foreign application system, you can amend the translation based on the English document of JP application which is identical to the original application.  Therefore, even if there is a discrepancy between the Japanese translation and the original application, you can amend the translation based on the English document.

                                                                       PCT Route vs. Paris Route

PCT Route

Paris Route


Foreign Application System



Time Restriction





(*2) The cost for filing fee in the foreign application system is 24,000 JPY.
(*3) generosity to the correspondence between a JP application (a Japanese translation) and an original application (a PCT application)
(*4) an admissibility to resolve a discrepancy between a JP document (a Japanese translation) and an original application (a PCT application)
(*5) In case the discrepancy between a JP document and an original application is major.


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