CDKN has been working with a range of expert organisations to provide technical assistance to nine developing countries as they prepare their INDCs for submission to the UNFCCC by October 2015. In this paper, Chris Dodwell and Emelia Holdaway of Ricardo-AEA with Kiran Sura and Helen Picot of CDKN summarise some of the key learning points that have emerged from this diverse experience. The submission of INDCs to the United Nations Framework Convention on Climate Change (UNFCCC) is a unique opportunity for developing countries to influence the shape of the new international climate regime, at the same time as accelerating their national actions. They are a necessary foundation for a successful outcome from the 21st Conference of the Parties to the UNFCCC (COP21) in Paris in December, and will be vital for underpinning effective climate policies in the years to come. Developing countries are placing a high priority on preparing their INDCs. INDCs present an opportunity for developing countries to showcase the practical steps they have taken in recent years to mainstream climate change into their development strategies.