The Nordic Partnership Initiative on Upscaled Mitigation Action (NPI) supported developing countries in designing and implementing mitigation action and attracting funding from international climate finance and carbon markets. In Peru, the initiative focused on building readiness for mitigating greenhouse gas emissions in the municipal solid waste sector. It generated comprehensive information on the sector’s status and trends in terms of waste and emissions, mitigation potential and costs, and barriers to action. Mitigation plans for landfills were prepared, a robust information system developed, and policy reforms introduced for recognising waste as a valuable raw material. The NPI results have been integrated into national and local development plans and serve as valuable building blocks in the design and implementation of Peru’s mitigation pledges under the Paris Agreement.