Navigating Divisional Filings in China
Introduction
As our journey through global divisional application practice continues, we turn our attention to China—a jurisdiction where the rules for filing divisionals are tightly linked to the procedural status of the original patent application. Chinese divisional practice is renowned for its unique timing requirements, complex layers of cascading divisionals, and strict procedural deadlines. For biotech and pharmaceutical innovators prosecuting patents in China, understanding these nuances is vital for secure, strategic portfolio management. This post demystifies the critical filing periods, the procedural labyrinth for voluntary and cascade divisionals, and practical pitfalls that could jeopardize future enforcement.
Periods for Filing Divisional Applications
In China, a divisional application can be filed:
1. At any time while a parent application is pending, but in no case later than the expiration of two months from the date of receipt of the Notification to Grant a Patent Right (which sets a two-month period during which the application proceeds through the formalities of registration) from the Chinese Patent Office. An Applicant can file a divisional application during these two months regardless of whether the Applicant proceeds with the formalities of registration (e.g., paying the issue fee) or abandons the application. However, an Applicant cannot file a divisional application after the expiration of the two months from the date of receipt of the Notification to Grant a Patent Right of the parent application, if the parent application has been withdrawn, or is deemed to have been withdrawn and has not been restored (e.g., reinstated).
2. Within three months from the date the Applicant receives a Notification of Rejection in a parent application (regardless of whether the Applicant requests reexamination of the Examiner’s decision or allows the application to go abandoned). A Notification of Rejection informs the Applicant that the application is rejected and that prosecution has been “closed” by the Examiner. An Applicant can file a request to the Board of Patent Reexamination (a Reexamination Request) to re-examine the application.
3. At any time after filing a Reexamination Request.
4. If an application is returned to the Examiner for further examination when the Board of Patent Reexamination (Board) overturns an Examiner’s rejection. During this period of further examination, an Applicant can file a divisional application. However, as mentioned previously herein, a divisional application must be filed no later than the expiration of two months from the date of receiving a Notification to Grant a Patent Right.
5. If the Board maintains an Examiner’s Rejection, the Applicant may appeal to court (e.g., a first instance court) within three months of receipt of the reexamination decision from the Board (Reexamination Decision). An Applicant can file a divisional application during these three months regardless of whether the Applicant files an appeal or allows the application to go abandoned.
6. After an Applicant appeals to a first instance court, after receiving a Reexamination Decision.
7. If a first instance court maintains the Reexamination Decision, an Applicant may appeal further to a second instance court within 15 days from receipt of the first instance court’s decision. Regardless of whether the Applicant files an appeal with the second instance court, the Applicant can file a divisional application within 15 days of receipt of the decision from the first instance court.
8. After appealing a decision from a first instance court to a second instance court.
9. If a first instance court overturns the Reexamination Decision.
Additionally, under current patent practice in China, a divisional application can be filed from a previously filed divisional application (meaning “cascading” divisionals are permitted). A cascading divisional can be filed voluntarily or in response to a lack of unity objection raised in a prior filed divisional application. An Applicant may file a further divisional application (a third filing) voluntarily based on a divisional application (a second filing) within any of the above periods 1-9 of an original filing. However, suppose an Examiner raises a unity objection in a divisional application (a second filing). In that case, the time during which an Applicant can file a further divisional application (a third filing) in response to the unity objection depends on the pendency of the second filing. Under this scenario, the Applicant must submit the third filing while the second filing is still pending.
In China, a divisional application has the same filing date as the very first (e.g., original) parent application. The actual date when the divisional application is filed is referred to as the “divisional submission date” (rather than the filing date). After a divisional application is filed, an Examiner reviews the divisional submission date to confirm that the divisional filing is correct and was not filed after the (1) expiration of the two months from the date of receipt of the Notification to Grant a Patent Right in the very first parent application; (2) withdrawal of the very first parent application; or (3) withdrawal of a very first patent application which has not been reinstated. In addition, the Examiner determines whether the divisional application satisfies any of items 1-9, above.
The divisional submission date is important for “cascading divisionals” (such as, for example, a second divisional application (divisional application 2) filed from the first divisional application (divisional application 1)).
Suppose a further filed divisional application (such as divisional application 2) is a voluntary divisional filed from a previously filed divisional application (such as divisional application 1). In that case, an Examiner will review the divisional submission date of divisional application 2 in connection with the status of the very first (e.g., original) parent application. Specifically, the Examiner will review the divisional submission date (of divisional application 2) to confirm that the divisional filing is correct and is not after: (1) the expiration of the 2 months from the date of receipt of the Notification to Grant a Patent Right in the very first parent application; (2) the withdrawal of the very first parent application; or (3) the deemed withdrawal of the very first patent application (which has not been reinstated). In addition, the Examiner determines whether the divisional application satisfies any of items 1-9 above (but as it relates to the status of the very first parent application).
Suppose a further filed divisional application (such as divisional application 2) is filed in response to a lack of unity objection raised by an Examiner in a previously filed divisional application (such as divisional application 1). In that case, an Examiner will review the divisional submission date of divisional application 2 in relation to the status of divisional application 1. Specifically, the Examiner will review the divisional submission date (of divisional application 2) to confirm that the divisional filing is correct and is not after: (1) the expiration of the two months from the date of receipt of the Notification to Grant a Patent Right in divisional application 1; (2) the withdrawal of divisional application 1; or (3) the “deemed” withdrawal of divisional application 1 (which has not been reinstated). In addition, the Examiner will determine whether divisional application 2 satisfies any of items 1-9 above (but as it relates to the status of divisional application 1).
The filing of a further divisional application based on a previously filed divisional application is often not possible because the very first parent application is granted, rejected, or withdrawn (e.g., is “closed”). However, if a previously filed divisional application (such as divisional application 1) was filed in response to a lack of unity objection, the filing of a further divisional application (such as divisional application 2) in response to the lack of unity objection is deemed to be an “exception”. If the further divisional application (divisional application 2) is not filed in response to the lack of unity objection against the divisional application 1 and the very first parent application is closed, the Examiner will reject the further divisional application (divisional application 2).
Requirements for Filing a Divisional Application
When filing a divisional application, a copy of the specification, abstract, and drawings from the parent application must be filed. A set of claims (either the original claims from the parent application or a new set of claims) must also be included. In addition, the following are also required:
1. Payment of all the necessary official fees (in the same amount as a new filing). Using an invention patent application as an example, the official fees include the filing fee and publication fee of RMB 950 (USD140), priority fee of RMB 80 (USD 12) per priority, the substantive examination fee of RMB 2,500 (USD 360), and any additional charges for excessive specification and claims (if any);
2. A Power of Attorney; and
3. Priority document of the parent application.
Claims of a Divisional Application
A divisional application may be filed with the claims as originally filed in the parent or PCT application. However, the claims of a divisional application filed using the claims of a parent or PCT application will need to be amended at some point during prosecution to ensure that neither the parent nor the divisional application claims the same subject matter. However, partial overlap of the subject matter between a parent and a divisional application is permitted (for example, if claim 1 of a parent application claims a guide wire having a length of 5 to 10 cm, claim 1 of a divisional application can recite a guide wire having a length of 1 to 20 cm).
Double Patenting
In China, an Applicant is entitled only to a single patent per invention (meaning that the claims of 2 patents cannot protect the same invention; therefore, the claims cannot have the exact same scope). In other words, what is “statutory” double patenting in the United States is not permitted. Thus, an Examiner may require amendment of the claims of either the parent or divisional application as necessary to ensure that neither application includes a claim for any identical matter claimed in the other application. Moreover, there is no obviousness-type double patenting in China.
Examination of Divisional Applications
A divisional application is treated as a substantive application and is accorded a separate application number, requires separate fees, requires a separate request for examination, will be prosecuted separately from the parent application, and will result in an independent patent from the parent application. As mentioned previously, the fees for a divisional application are the same as for any parent application. The term of patent for a divisional application is twenty years for an invention, ten years for a utility model, or fifteen years for a design patent, from the filing date of the very first (e.g., original) parent application.
Special or Unique Requirements for Filing a Divisional Application in China
The periods applicable for filing a divisional application, such as the time limit for requesting substantive examination or paying the fee for requesting substantive examination, are calculated from the initial filing date (or priority date) of the very first parent application. Suppose a time limit has expired or is less than two months from the divisional submission date. In that case, the Applicant is permitted to complete any formalities or pay any required fees within two months from the divisional submission date or within 15 days from receipt of the Notification of Acceptance of the divisional application.
A divisional application cannot be used to change the application type (such as an invention, utility model, or design) of the parent application. In other words, if the parent application is for a utility model, a divisional application cannot be filed directed to a design.
The inventor(s) of a divisional application must be the same as or be included in the list of the inventors contained in the parent application.
Additionally, an Applicant for a divisional application cannot be different from its parent application. If the Applicant of the parent application is to change, the change must be made before filing a divisional application. Alternatively, if the Applicant of a divisional application is to change, the change must be made after the filing of a divisional application.
Key Takeaways
Interlocking Filing Windows: In China, divisional applications can generally only be filed while the parent application is pending, with short windows triggered by grant notifications or rejection notices.
Cascading Divisionals Strictly Policed: When filing a divisional from a previous divisional (a "cascade"), the key date is always tied back to the procedural status of the original parent application, NOT just the immediate predecessor.
Critical Deadlines: Once a Notification to Grant a Patent Right is received, a strict two-month window applies to file new divisionals, regardless of further prosecution activity.
Pitfalls for the Unwary: Filing outside a valid window, or after the parent has been withdrawn or deemed abandoned (and not restored), will lead to rejection.
Strategic Dos and Don’ts: Proactively map divisional strategy early, coordinate closely with Chinese counsel, and continuously track the status and deadlines for the root parent application to avoid fatal missteps.
With its procedural rigidity and unforgiving deadlines, China’s divisional practice demands strategic foresight and meticulous attention to prosecution timelines—especially for pharma and biotech portfolios where portfolio life and enforcement prospects are paramount.
This post was written by Lisa Mueller of Casimir Jones, Daisy Zhong, and Jason Zhong of Zhong Lun.