When can I file a divisional application in Japan?

In Japan, the timing to file a divisional application is limited to the following:

1. The timing when the applicant can amend the claims
2. Within 30 days from issuance of a Decision of Allowance (except after a Decision of Rejection has been issued), but only before patent registration (patent fee payment period)
3. Within 4 months from issuance of a Decision of Rejection (appeal period)

This leads to the following four situations:

(1) Before an Examination Decision
    – Before the first OA
    – During the response period to an OA

(2) After a Decision of Allowance
    – A divisional application can be filed within 30 days after a Decision of Allowance. However, once the patent is registered (after paying the patent fees), a divisional filing is no longer possible

(3) After a Decision of Rejection
    -A divisional application can be filed within 4 months after a Decision of Rejection

(4) After the filing of an appeal
    – The only situation where a divisional application can be filed after filing an appeal is when the JPO issues a new Office Action during Pre-Appeal Examination or Appeal Examination

Since the above is complicated, we have summarized it in the flowchart below:

For a better understanding, four typical patterns A–D are illustrated below, with the period when a divisional application can be filed shown in orange and the period when a divisional application cannot be filed shown in gray.

Pattern A is a case where a patent is granted without a Decision of Rejection.

As shown above, while a divisional application can be filed within 30 days after a Decision of Allowance, it is important to note that a divisional application cannot be filed after patent registration.

In other words, a divisional application after the Decision of Allowance must be filed before paying the patent fees.

On the other hand, Patterns B to D are cases where a Decision of Rejection is issued and the applicant files an appeal.

Once a Decision of Rejection is issued, a divisional application cannot be filed even if a Decision of Allowance is issued during Pre-Appeal Examination (Pattern B) or an Appeal Decision of Allowance or Rejection is issued as a result of appeal examination (Pattern C).

The only case where a divisional application can be filed after an appeal is when an Office Action is issued during Pre-Appeal Examination or Appeal Examination (Pattern D).