PurposeCareer theorists have been increasingly occupied with role transitions across organisations, neglecting role transitions undertaken within single organisations. By exploring in depth the aspects of career capital that role holders need to facilitate their own organisational role transition, this article builds upon career capital theory.Design/methodology/approachAdopting an interpretivist approach, this study explores the experiences of 36 business leaders who have undertaken a recent role transition within a UK construction business.FindingsThe article empirically characterises 24 career capital aspects, clustered into Knowing Self, Knowing How and Knowing Whom. It argues that these aspects are important to internal role transitions and compares them to mainstream career capital theory. In addition, the concepts of connecting, crossing and investing career capital are introduced to explain how career capital supports such transitions.Research limitations/implicationsThis study proposes a new career capital framework and refocuses debate on organisational careers. It is based on a single organisation, and it would be beneficial for future researchers to explore its applicability within other organisations.Practical implicationsThe article explores the implications of the new career capital framework for business leaders and organisational managers who wish to build individual and organisational career mobility.Originality/valueThis study proposes a new, empirically grounded, career capital theoretical framework particularly attending to organisational role transitions.