Becky Geeson lectures in the Initial Teacher Training and leads two primary undergraduate degrees. She joined Bishop Grosseteste University in 2011 following twelve years teaching in Lincolnshire primary schools in a variety of roles including senior leadership and during this time gaining Advanced Skills Teacher (AST) status. She will soon complete a doctorate in education focussing on teaching assistants becoming teachers.After teaching in mainstream primary schools for almost 18 years, Emma Clarke now teaches on a primary PGCE course. Her interests include research methodologies, approaches to managing behaviour, and challenging behaviour in primary schools. Her PhD considered the tensions experienced by teaching assistants in mainstream primary schools when managing behaviour. She has presented her research nationally and internationally, as well as publishing both in books and peer-reviewed journals. Crossing the line: Constructs of TA IdentityThis paper considers issues around identity for teaching assistants (TAs) in mainstream English primary schools. We discuss the concomitant problems TAs experience around role definition and role-creep as well as the challenges inherent in equivocally defining their evolving and flexible role. We used key themes drawn from the literature considered to suggest that professional identity is broadly socially, relationally and contextually dependent, changeable and multifaceted. We then explore how these terms relate to the work and roles TAs undertake in school.The paper concludes with recommendations for schools to support the development of a contextually relevant identity for TAs so the flexibility in their role can be advantageous for TAs, teachers and children.