Summary In contemporary welfare states, the non-take-up of rights is a pervasive and considerable problem. Yet, our empirical and theoretical understanding of this phenomenon is still rather limited. In this context, the historical role of social work practice in bridging between citizens and the welfare state cannot be overlooked. To adequately tackle non-take-up, there is an urgency for usable knowledge that is oriented towards practice. In this article, we address this issue by studying Integrated Rights-Practices that focus on overcoming non-take-up through proactive, outreaching, generalist and relation-based interventions. We conducted a qualitative realist evaluation (n = 18) with the intention to explain how and why these interventions provide an answer to the determinants of non-take-up. Findings We argue that the aforementioned guidelines – referring to the ‘who’, ‘where’, ‘what’ and ‘how’ of social interventions – are not to be considered separate strategies, but should rather be understood as synergistic, jointly activating 10 generative mechanisms that overcome the information, process and social costs associated to non-take-up. Applications This article makes both a methodological and theoretical contribution. First, the potential of realist evaluation has convincingly been advocated for by different authors in social work academia, but empirical examples have been lacking hitherto. Second, the identified mechanisms and interventions can provide inspiration to develop similar practices to tackle non-take-up in other welfare regimes and contexts.