Recently, our firm won the second instance of an administrative lawsuit on invalidation declaration of a patent for invention, successfully having the patent fully invalidated by th...
Recently, our firm won the first instance of an administrative litigation case for invalidation of an invention patent, in which it is ruled that the invention patent should be comp...
Comparison of IP5 Restrictions to Corrections in Patent Invalidation Procedure Concerning Technical Features Not Included in Patented Claims
Xiaowen SONG
Chinese Patent Attorney
It is widely recognized that restrictions on corrections made in the patent invalidation procedure before the CNIPA have been slightly loosened in recent years. However, the principle that a technical feature not included in the patented claims generally cannot be added still applies, which imposes a strong restriction on the patentee. Are there similar provisions applied to the invalidation procedures in the JPO, the KPO, the USPTO, and the EPO, the other IP5 bureaus? The author conducted a brief comparison for your reference.
I. JPO and KPO
Referring to the Comparative Study on “Requirements for Post Patent Grant Corrections (Amendments)” and Purpose of the Requirements in Japan, China and Korea1 (hereinafter referred to as “Study report”) released by the CNIPA on January 20, 2025, the Japanese practice allows for corrections to reduce the scope of the claims in the post-grant invalidation procedure, but does not allow for the addition of new matters (Japanese Patent Law Article 126 (1) and (5), Article 134-2(9)); and the Study report, Page 14, Comparative Table, Requirement 5). The KPO also requires that corrections do not aim to add new matters (Patent Act Article 136(3) and Article 133-2(4)), as referenced in Requirement 5 of the Study Report. But neither Japan nor Korea stipulates restrictions specifically for corrections based on technical features not included in the patented claims.
II. EPO
Pursuant to EPC Article 123 (2) and (3), any correction may not be made in such a way that it contains subject-matter which extends beyond the content of the application as filed; and the European patent may not be amended in such a way as to extend the protection it confers. Under Article 80 of the Implementing Regulations to the Convention on the Grant of European Patents, the description, claims and drawings may be amended in the opposition procedure, provided that the amendments are occasioned by a ground for opposition under Article 100, even if that ground has not been invoked by the opponent.
Hence, EPO does not impose specific restrictions to corrections based on technical features not included in the patented claims.
III. USPTO
The post-grant invalidation procedure in the US takes various forms, such as the Ex Parte Reexamination（EPR) relatively lesser-discussed recently, and the Inter Partes Review (IPR) widely exploited in recent years. According to Docket Navigator based on public data of the PTAB, for IPR petitions filed since October 1, 2024, 72% have been denied while IPR petitions filed between January and August of that same year enjoyed a 61% institution rate2. In view of the dramatic lift of the bar for IPR institution, EPR is also taken into consideration in the study herein on the restrictions to corrections in the invalidation procedure.
In EPR, under 35 U.S.C. 305, the patent owner will be permitted to propose any amendment to his patent and a new claim or claims thereto, in order to distinguish the invention as claimed from the prior art cited; but no proposed amended or new claim enlarging the scope of a claim of the patent will be permitted in EPR.
Whereas in IPR, under 35 U.S.C. 316(d)(1)(B), the patent owner may file 1 motion to amend (MTA) after institution to propose, for each challenged claim, a reasonable number of substitute claims. Further, under 35 U.S.C. 316(d)(3), the amendment may not enlarge the scope of the claims of the patent or introduce new matter.
On October 18, 2024, the USPTO final rules governing Motion to Amend practice and procedures provide patent owners with greater flexibility when amending claims in IPR3. However, the scope of an MTA is limited to amendment(s) that respond to a ground of unpatentability involved in the proceeding. Under 42.121(a)(2) of Codes of Federal Regulations (CFR), an amendment cannot seek to broaden the scope of the claims of the patent or introduce new subject matter.
In light of the above, in either EPR or IPR, the author did not find a restriction specifically imposed to an amendment by “a technical feature not included in the patented claims.”
IV. CNIPA
The latest revision to the Guidelines for Patent Examination in China still stipulates in Article 4.6.1 (4) of Chapter 3, Part 4 that an amendment made during the invalidation procedure “generally shall not add a technical feature not included in the patented claims.” In the parallel proceedings, China may provide the strictest provisions in this aspect among the IP5 countries. Meanwhile, in accordance with Article 5.2.1.3 (4) and (5) of Chapter 8, Part 2 of the Guidelines for Patent Examination, when replying the Office Action, the examiner may, under Rule 57 Paragraph 3 of the Implementing Regulations of the Chinese Patent Law, decline addition of a new independent claim added by the applicant on his own initiative and defining a technical solution that is not present in the initial claims. Accordingly, if the disclosure of potentially patentable inventiveness in the description is not included in the claims in a timely manner, there is a risk that such disclosure may not be allowed to be added to the claims later, either in response to office actions or in the post-grant procedure, and consequently a patent that could have been sustained based on corrections in the invalidation procedure may be declared entirely invalid.
In light of this, during patent drafting and making voluntary amendment prior to the office action stage, it is necessary to have an experienced patent attorney to sufficiently run through the inventive points to ensure that all valuable features have been deployed in the claims of Chinese patent applications. In particular, the additional fee charged by the government for claim items exceeding 10 items in a patent is as low as 150 yuan per item. If the application document upon filing contains a relatively limited number of claim items, it is advisable to sort out the inventive points again to confirm whether it is necessary to add new claims during or before the period for making voluntary amendments.
As mentioned above, China’s local practice engages the afore-described possible distinctions from the practice at the other IP5 countries in terms of the restriction to the amendments made in the invalidation procedure. Applicants from across the world may use China’s local practice to our own advantage while taking note of the above distinction.
V. Conclusion
The author infers that the distinction of China’s practice from the corresponding practice at the other IP5 bureaus with regard to the restriction to the amendments made in the invalidation procedure is based on the consideration of keeping the efficiency of invalidation examination and reducing the workload of examination. After all, the Reexamination and Invalidation Department has shouldered an immense workload, handling 9,100 patent invalidation requests in 2024 alone4. There is also the opinion that such a restriction is imposed in hope of preventing the invalidation procedure from turning into substantive examination for patent granting, to thereby save the time spent by the Reexamination and Invalidation Department on this matter5. Additionally, the author reckons that China confines the grounds for amendments in the validation procedure to be within the scope of the patented claims to, to some extent, improve the predictability by the public, thereby balancing the benefits and interests between the patentee and the public, which is adaptive to the China’s current level of innovation and development.
In any case, it is necessary that applicants keep an eye on the trends and developments of the relevant practice, so as to secure a favorable position throughout the patent granting and post-granting process.
————————————————————————————————————
1https://www.cnipa.gov.cn/art/2025/1/20/art_2633_197268.html 2https://www.mintz.com/insights-center/viewpoints/2231/2025-08-28-ptab-pendulum-swings-how-ipr-denials-are-reshaping 3https://www.fr.com/insights/thought-leadership/blogs/final-motion-to-amend-rules-now-in-effect-at-the-ptab/ 4https://mp.weixin.qq.com/s/7r0q0NA0O_Zs-N0E-eMxmQ 5Yin Xintian, “Detailed Explanation of China’s Patent Law” Page 481-482, Intellectual Property Publishing House
