This report describes the secretariat’s activities relating to the technical expert review of biennial transparency reports in the reporting period 1 November 2025 to 31 August 2026. It provides an update on the status of submissions of biennial transparency reports and the reviews thereof; an overview of the training of technical expert reviewers and the 3^rd meeting of lead reviewers; and information on voluntary reviews of information on climate change impacts and adaptation, simplified reviews of national inventory reports, and reviews of technical analyses of activities set out in paragraph 70 of decision 1/CP.16. Furthermore, the report presents challenges encountered by the secretariat, Parties and technical expert reviewers in conducting the reviews.