The acronym EMMA stands for “Evaluation and Mentoring of the Multi-Agency Approach to Violent Radicalisation” and wants to provide answers to the challenges of multi-agency work (MAW). As stated by the RAN policy paper 2018 MAW structures and working processes are crucial for early and effective identification of individuals at-risk, improved information-sharing, joint decision-making and coordinated action. MAW breaks down historical silos between agencies and leads in different cities to cooperation, instead of fragmentation of services. Although practitioners and academics endorse the added value of MAW, they also pinpoint on some prerequisites of building an effective collaboration (building trust, awareness, ethical and legislative guidance, etc.). Two main challenges for MAW have been identified, namely (1) the lack of established policies and procedures for MAW in countering violent extremism, (2) thorough evaluation research of MAW approaches and (3) the barriers of information sharing.