A key principle upon which the Revised Special Educational Needs and Disability (SEND) Code of Practice 0-25 (2015) is based is children's involvement in decision-making that affects them, and a significant change is the removal of the term "behaviour" and an emphasis on social, emotional and mental health (SEMH) needs. To ensure that child involvement is a practical reality for children with SEMH needs, staff in schools benefit from a range of evidence-informed strategies for engagement and participation. This article describes an approach to the provision of learning mentor services for children with SEMH in a primary school based on partnerships between the children and staff in establishing and measuring change. Limitations are noted and suggestions for future developments are also made.