This paper reports on a study which seeks to identify how to increase volunteer participation by converting non-volunteers to the benefits of volunteering. The project uses the concept of volunteerability – an individual’s propensity to volunteer based on their willingness, capability and availability – to identify ‘convertibles’. Convertibles are conceptualised as a group of individuals with a high propensity to volunteer but who do not currently do so. Data collected from an exploratory study based on 12 focus groups with current, non-active and non-volunteers seeks to identify what factors are indicative of individuals having a high level of volunteerability and what factors inhibit volunteer participation, with a view to enabling the development of interventions for organisations to improve volunteer recruitment and engagement.