In Taiwan's patent invalidation proceedings, any person may file an invalidation request against a granted patent by submitting a statement of invalidation, the reasons, and prior art evidence, while specifically explaining the correspondence and comparison results between the disclosures in the prior art evidence and the technical features of the claims. The Taiwan Intellectual Property Office (the “TIPO”) defines the disputed “issues” of the invalidation action based on “the statement of invalidation, the reasons, and the prior art evidence,” and conducts investigation of evidence and examination of patent validity within the scope of those issues. Where the TIPO relies on some passages in the prior art evidence – but such passages had not been cited by the invalidation requester – then rendering a decision finding the invalidation action well grounded, the patentee adversely affected by the decision may seek administrative remedies on the ground of procedural prejudice. In a recent invalidation action concerning Taiwan Invention Patent No. I691922, the TIPO rendered a decision finding the patent to lack an inventive step based on passages that were not cited by the invalidation requester. The patentee subsequently filed an administrative appeal, arguing that the TIPO conducted an ex officio examination without giving the patentee an opportunity to respond. After an unsuccessful administrative appeal, the patentee filed an administrative lawsuit with the Intellectual Property and Commercial Court (the “IPC Court”).
In its 2024 Xing Zhuan Su Zi No. 57 judgment, the IPC Court dismissed the patentee's lawsuit, holding that the TIPO made its determination within the scope of the issues raised by the invalidation requester and was not bound by the parties' statements. The IPC Court found that, throughout the invalidation proceedings and the administrative lawsuit, the issues were about whether the combinations of the prior art evidence could establish that the patent lacks an inventive step. Although the passages of the prior art evidence relied upon by the TIPO differ from those cited by the invalidation requester, such passages did not go beyond the scope of the evidence or the disputed issues. In addition, the IPC Court held that the evidence submitted in the invalidation action could establish that the patent lacks an inventive step. Dissatisfied with the judgment, the patentee appealed to the Supreme Administrative Court. On August 13, 2026, the Supreme Administrative Court rendered its 2025 Shang Zi No. 522 judgment, emphasizing that, within the scope of the statement of invalidation, the TIPO may consider all arguments made by the parties and the results of the investigation of facts and evidence, and make its determination based on the rules of logic and experience. Therefore, even if the reasoning of invalidation decision differs from the correspondence and comparison results asserted by the invalidation requester, it still constitutes a determination by the TIPO within the scope of the disputed issues. Accordingly, the Supreme Administrative Court dismissed the patentee's appeal.
During the administrative remedy proceedings, the patentee repeatedly argued that the invalidation decision's reliance on passages not cited by the invalidation requester violated Article 75 of the Patent Act, which requires the TIPO to notify the patentee to respond when it examines, ex officio, reasons and evidence not provided by the invalidation requester. In this regard, the Supreme Administrative Court stated that the “ex officio examination” under Article 75 of the Patent Act is an exceptional mechanism initiated by the TIPO, for public interest purposes, with respect to matters outside the disputed issues raised in the invalidation action. For example, where a judgment in a civil infringement lawsuit involves other evidence concerning patent invalidity, or where, during the consolidated examination of multiple invalidation actions, the TIPO finds that evidence submitted in different invalidation actions may corroborate one another, the TIPO may, ex officio, examine reasons or evidence not provided by the invalidation requester and give the patentee an opportunity to respond. In this case, however, the passages of evidence relied upon by the TIPO did not go beyond the scope of the issues. The Supreme Administrative Court therefore held that Article 75 of the Patent Act did not apply in this case.
Based on the above court judgments and the TIPO's practice, when examining an invalidation action, the TIPO may make its determination by considering the parties' arguments and investigating the prior art evidence, and is not limited to the passages of the prior art evidence cited by the parties. Accordingly, where an invalidation decision relies on evidence passages different from those cited in the reasons for invalidation, it may still be considered to remain within the scope of the disputed issues raised in the invalidation action. Therefore, when facing an invalidation action, the patentee should not only reply to the reasons for invalidation and the passages in the evidence cited by the invalidation requester, but should also pay attention to other passages in the submitted evidence that were not cited by the requester, as a basis for considering how to respond to the invalidation action or whether to request a post-grant amendment.