Study Aims: The aim was to use theoretical understandings of behavioural change, from the COM-B model, to explore the experiences of experts from different contexts working with survivors who may have BI and to make recommendations for training in UK third sector DV organisations. Participants: Eleven experts by profession and experience in the field of brain injury and/ or domestic violence from the United Kingdom and United States of America. Methods: Qualitative methodology was employed. Data were collected using semi-structed individual interviews. Data were analysed using reflexive thematic analysis and adopted a critical realist philosophical approach. Analysis: Analysis constructed three themes with nine subthemes which are explored in detail, these are: 1) Lack of understanding of traumatic brain injury and domestic violence, 2) Specified educational needs of practitioners and 3) Changing practitioners’ behaviour. Major implications: The participants identified factors which influenced practitioners working in UK domestic violence third sector organisations understanding of brain injury in domestic violence survivors, including a gender and racial biases. Participants felt that how change is implemented and maintained in the long term needs to be considered thoughtfully. The behaviour change wheel (Michie et al., 2014) is one way which organisations could identify what they need to do to support organisational and individual level change in practice. Keywords: Brain Injury, Domestic Violence, Third Sector, Training, Behaviour Change