This paper explores the experiences and perceptions of a little-known category of in-service trainee teachers in the Further Education (FE) and Skills sector in England: those who meet the practical teaching requirements of their course mainly through unpaid teaching as "volunteers." The paper reports findings from mixed-methods research which used surveys, interviews and focus groups involving trainee teachers within a large FE-HE partnership. Themes relating to motivations to volunteer, the development of teacher identity within marginal roles, and the risks associated with unpaid teaching are discussed. For increasing numbers of trainees, unpaid teaching provides an opportunity for career entry. However, the quality of teaching experience gained is mixed, with some trainees receiving high levels of support, whilst others experience marginalisation and limitations on their developing teacher identities. The paper highlights the specific challenges to professionalism posed by unpaid teaching within the FE and Skills sector, and relates these challenges to a broader context of insecurity and risk. As work experience becomes an increasingly valuable commodity, this paper illustrates the pressures individuals face as they exchange payment and security for the opportunities volunteering provides.