Pupils with Social Emotional and Mental Health (SEMH) needs are disproportionately excluded from schools in England. Drawing on data collected from interviews with Local Authority Education Officers in 2017/18 in a project that looked at disparities in rates of permanent exclusion across the UK, this article explores how the influence of perverse incentives in the system, as well as the potentially different primary concerns of actors involved in inter-professional work, may undermine practices of inclusion in schools, and lead to the exclusion of pupils with SEMH. The review of existing literature and current analysis presented in this article highlight a number of potential factors which may be leading to the exclusion of pupils with SEMH in England. The data analysis and proposed theoretical frameworks contribute to the knowledge on ways in which the fragmentation of the English school system has failed many SEMH learners. Our argument here is that professional communication to support pupils with SEMH requires inter-professional understanding and respect for the primary concerns of different agencies. However, in circumstances of challenge and limited resources, there is a heightened risk that pupils with SEMH can become collateral casualties of policy change evacuated to the social margins of schooling.