Vocational teachers' prior occupational experiences are construed as those that will guarantee high-quality teaching in vocational education, although individuals are no longer required to have formal teaching qualifications to be employed as teachers in Sweden. This lack of strict requirements raises the issue of the preparedness of vocational teachers to teach their subject matter. Drawing on a socio-cultural understanding of identity, and based on twenty semi-structured interviews with vocational teachers in different subject areas, this article addresses vocational teachers' identity formation through boundary crossing; these individuals cross boundaries between the community of the prior occupation's practice, the teaching occupation and the community of teacher training. The analysis illustrates how teachers who manage to balance their teacher identities with their occupational identities by maintaining their participation in the different communities seem to be the best prepared to teach their vocational subjects. As many of those we interviewed do not manage to keep such a balance, we argue for the need for in-service training for vocational teachers to help them keep up to date with, participate in and continue to belong to the communities of their former occupations.