Transparency is the bedrock of the Paris Agreement (PA), including the assessment of that information by qualified experts to ensure consistency with international requirements. Review processes in one form or another have been underway within the UNFCCC for over 20 years. The PA’s Enhanced Transparency Framework introduces a dramatic increase in the scale of review under the UNFCCC process, as it involves several major changes. Because of these changes, simply building on what has been done for the review process in the past is unlikely to succeed. Instead, we argue that it is necessary to “rethink and redesign” a process to support effective and efficient reviews of biennial transparency reports (BTR) for all Parties. This paper presents a road map for building on the best of the current UNFCCC review processes and then identifies solutions to address the most important challenges faced by Parties, the UNFCCC secretariat, and review experts to establish a functioning ETF review process.