Where this document refers to “countries” or “governments”, it is also intended to include “regional economic organisations”, if appropriate. The authors would like to thank the following OECD and IEA colleagues for their helpful comments on this paper: Simon Buckle, Jane Ellis, Takashi Hattori, Christina Hood, Takayoshi Kato and Raphael Jachnik. This enhanced transparency framework will play an important role in tracking progress towards the individual and collective goals agreed at COP 21 and in understanding achievement of nationally determined contributions under the Paris Agreement. This paper unpacks the transparency-related provisions within the Paris Agreement and Decision 1/CP.21 relating to mitigation and support. It also explores the relationship between the existing and future transparency framework, information required to track progress towards nationally determined contributions for mitigation, and fulfilling reporting provisions on finance provided, mobilised and received.