Research and development with regard to interprofessional practice have extended over recent decades to early years services in children's centres (CCs). However, most children in England attend private and voluntary settings, rather than CCs. where early years practitioners have varying amounts of opportunity, training and experience to work interprofessionally. Developing our Social Practice analysis of case studies, we propose a theoretical framework for interpreting early years interprofessional practice that takes account of specific contexts, noting conditions which promote boundary-crossing competence. This paper presents selected findings from a survey of 52 early years practitioners from England about their experiences of interprofessional working, woven together with case study exemplars. Their extensive responses to open-ended survey questions showed great variation in work with other professions and in reported levels of confidence and competence. However, there were also differences depending on the setting type. Findings suggest the need to tailor training to individual contexts, and argue for securing space for practitioners to gain experience of interprofessional working through mentored opportunities. (author abstract)