A Practical Guide to Patent Term Adjustment (PTA) in China
- CN-KnowHow IP Group
- Nov 7, 2024
- 4 min read
The fourth revision of China’s Patent Law came into effect on June 1, 2021, and there has been significant interest in Article 42, Paragraph 2, which addresses Patent Term Adjustment. Many patent holders have already submitted PTA requests since then.
On January 20, 2024, the Examination Guidelines and Implementing Rules of the new Patent Law were implemented, setting out the rules and standards for PTA. Recently, the CNIPA published the updated fee schedule, including adjustments for PTA-related costs, and formally began reviewing the submitted PTA cases.
This article summarizes the recent updates on PTA, provides practical case studies, and explains how to determine eligibility and calculate potential adjustment days.
Frequently Asked Questions:
What is PTA?
Patent Term Adjustment (PTA) compensates for delays caused by the CNIPA during the patent examination process. It aims to address administrative delays that prolong the time taken to grant a patent.
Is my patent eligible for PTA?
PTA is available for all types of invention patents, but the "4Y3Y rule" must be met. This rule requires that the subject patent be granted more than:
- Four years from the filing date of the invention patent application.
- Three years from the date of the request for substantive examination.
According to Article 42, Paragraph 2 of the fourth revision of the Patent Law, effective June 1, 2021: If a patent is granted more than four years from the filing date and more than three years from the request for substantive examination, the CNIPA, upon the applicant's request, shall compensate for any unreasonable delays during the examination process, excluding delays caused by the applicant.
When should I submit a PTA request?
A PTA request must be submitted to the CNIPA within three months from the date of the patent grant announcement. If this deadline is missed, there is no option for extension or recovery.
How much does it cost?
When submitting a PTA request, the applicant is required to pay a PTA request fee of 200 RMB per application. Additionally, once the CNIPA issues the decision to grant patent term compensation, the applicant must pay the annual fee for the compensated term (8,000 RMB per year) in a lump sum before the 20-year patent term expires.
How Many Days Can I Receive Upon PTA, and How Is It Calculated?
The patent term adjustment for invention patents is calculated as follows:
PTA in China = (patent grant date – date of 4Y/3Y) –reasonable delay – unreasonable delay by applicant.
This calculation involves determining the number of days for reasonable and unreasonable delays. These will be clarified in the following case study.
Will the new compensated date appear on the patent certificate?
No. After submitting the PTA request, the patent holder will receive a notice from the CNIPA specifying the number of days compensated and the corresponding fees. This number will not appear on the patent certificate but will be recorded in the patent registration system.
A Real Example

Patent Basic Information
This case involves a divisional application for an invention patent:
- Application Date: October 18, 2011
- Divisional Filing Date: February 6, 2015
- Publication Date: August 26, 2015
- Request for Substantive Examination: March 6, 2015
- Rejection Notice Date: November 13, 2018
- Reexamination Decision Date: March 27, 2019
- Grant Announcement Date: October 26, 2021
Since the request for substantive examination was made before the publication date, the examination request date is considered the publication date. The case also underwent reexamination, with the rejection notice dated November 13, 2018, and the reexamination decision on March 27, 2019.
The applicant requested an adjustment on December 10, 2021, and received the PTA decision notice on September 19, 2024, granting a two-year term adjustment.
- Original Expiration Date: October 18, 2031
- New Expiration Date: October 17, 2033 (2 Years Added!)
The total amount spent included the PTA request fee of 200 RMB and the two years of annual compensation fees totaling 16,000 RMB (8,000 RMB per year). These fees must be paid within one month of receiving the PTA decision notice, with no extension allowed.
Calculation:
PTA in China
= (patent grant date – date of 4Y/3Y) –reasonable delay – unreasonable delay by applicant
= 994 - 134 - 70 - 60
= 730 days
Where:
- 994 days: Time from the grant date to the 4Y/3Y threshold.
- 134 days: Reasonable delay due to the review of amendments.
- 70 days: Unreasonable delay due to a late response to an Office Action (OA3).
- 60 days: Unreasonable delay due to a late response to another Office Action (OA5).
Reasonable delay in this case
Reexamination Procedure Involving Amendments to Patent Application Documents: Date of issuance of review decision: 2019-3-27 - Date of issuance of rejection notice: 2018-11-13 = 134 (days)
Suspension of Proceedings Due to Disputes over Patent Ownership as Stipulated in Rule 103: None
Suspension Procedures Due to Property Preservation Provisional Measures as Stipulated in Rule 104: None
Other reasonable circumstances such as administrative litigation procedures: None
Unreasonable delay in this case
Delay Caused by Failing to Respond to a Notification, the number of days delayed is from the expiration date to the actual date of submission of the reply;
OA3 actual reply date 2020-2-2 - original reply date 2019-11-24 = 70 (days)
OA5 actual reply date 2021-6-11 - original reply date 2024-4-12 = 60 (days)
Delays Resulting from Request for Deferred Examination: None
Delays Caused by Incorporation by Reference: None
Delays Caused by Request for Reinstatement of Rights. For delay caused by request for restoration of rights, the number of days of delay is from the expiration date of the original deadline to the date of issuance of the approval notice of the request for restoration of rights. Except when it can be proved that the delay is caused by the Patent Office: None.
Conclusion
The implementation of Patent Term Adjustment (PTA) in China is still in its early stages of practical application, making many of its rules open for discussion. We previously provided a brief introduction to the use of PTA in the new Patent Law Implementing Regulations, and now we have a particularly illustrative case to share. While there is no fundamental difference between PTA and Patent Term Extension (PTE), the requirements for applicants and the application standards differ. If you are unsure whether your patent is eligible for PTA or PTE, please feel free to contact us for further assistance.