This paper outlines Save the Children´s approach to core support. It includes some of the basic principles and requirements for its application in partnership with child rights organisations and networks. This guidance document helps Save the Children to ensure a common understanding and way of working when in a core support relationship with civil society partner organisations and networks. This new partnership modality has been developed specifically for the Global Civil Society Strengthening Programme 2022-2026, funded by the Swedish Development Agency (Sida), but can be applied across the programmes we support.