Supreme audit institutions (SAIs) are a critical part of public accountability systems. They ‘watch’ over governments’ use of public money and report about it publicly, helping to increase transparency. SAIs have an interest in strongly engaging with external stakeholders – including citizens – to make sure that their work is relevant, understood and used to hold governments to account. This paper provides a compilation of European SAIs’ practices on communication, co-operation and collaboration with external partners and is intended to provide inspiration to SAIs of EU candidate countries and potential candidates to further strengthen their engagement with their non-governmental stakeholders.