In response to calls to extend working lives, there is increased interest in people starting self-employment after the age of 50. However, the question of why people become self-employed at this time is generally assumed in the literature rather than empirically examined. Current assumptions include that it relates to (1) opportunity or necessity; (2) changes in autonomy preferences relating to the ageing process; or (3) entrepreneurial aspirations. This article empirically explores the pathways into self-employment and develops a theoretical model to better answer the question why people move into ‘solo’ self-employment after age 50. Using a sociological lifecourse theory, it demonstrates how transitions into self-employment are socially embedded and influenced by events preceding the transition. The 20 in-depth lifecourse interviews with people aged 50+ identified three pathways to self-employment after 50: a ‘turning point’ pathway, a ‘retirement’ pathway and an ‘entrepreneurial orientation’ pathway. The turning point pathway was most common, involving negative changes at work or in health and/or the family that appeared to generate or enhance a desire, or need, for more autonomy at work that was difficult to find as an employee. Crucially, ‘linked lives’ and ‘life stage’ provided an opportunity structure that made the move into self-employment feasible, by de-risking it and providing opportunities. The article contributes to academic and policy debates by highlighting the importance of changes over the lifecourse and support from others, and questions the extent to which these transitions can be attributed to the individual ageing process or to (long-term) entrepreneurial aspirations.