Methodological choices made this year on refined definitions and accounting approaches represent progress but it may be some time before they can be systematically implemented and before data can be consistently and routinely collected. Improved methodologies for more robust estimates would need to take into account the effects of public finance for capacity building or budgetary support, and of public policies, while also considering the role of domestic conditions for enabling private financial flows. We note in particular that there are opportunities for developed country Parties to improve on the transparency and comprehensiveness of their climate finance reporting under the UNFCCC. The OECD and CPI stand ready to support and continue to co-operate with and contribute towards these efforts.