In England, the Special Educational Needs and Disabilities Code of Practice (2015) was heralded as a significant reformation of provision for children and young people with additional and complex learning needs. Effective implementation of the Code requires the key implementers, Special Educational Needs Co-ordinators (SENCos), to develop and negotiate provision in their settings, to interface with colleagues, families and expert professionals, and to apply for and implement Education and Health Care (EHC) plans for the children and young people with the most complex needs. However, whilst this added to SENCo workload and responsibilities, systemic, resource and dominant discourse challenges remained the same. EHC plans have been described as a microcosm of the wider arena of policy and practice. Studies exploring SENCo perceptions of the enablers and challenges, which has import for commissioners and practitioners, are limited. This article presents part of a mixed-methods study which examined SENCo perceptions of the salient external and internal influences on EHC plan implementation. Integration of the analysed data sets uncovered themes related to purpose, support, communities of learning, and relationships. Key recommendations, whose enactment would support and develop SENCos, so they in turn can best promote the learning, development, wellbeing and inclusion of children and young people with SEND, and their families, are made. This article closes by proposing that the need for a professional information hub and support mechanisms for SENCos has never been greater.