The “building circularity into NDCs” user guide and digital toolbox aim to support countries to assess, prioritize, implement and track circular economy interventions for increased ambition and implementation of their NDCs. The toolbox provides guidance and tools for each stage of the policy cycle. Users can jump in at any stage with tools and options to report the interventions, targets, and indicators in the NDC. The tools have been selected according to established criteria including applicability at the national level, being previously tried and tested, and their relevance to the specific objectives of reducing GHG emissions. The tools allow the user to build on existing national data or use data from available tools as needed.