Despite the rise of in-work poverty across Europe, the psychological consequences of individual economic vulnerability are still rather unknown. Drawing on both objective and subjective conceptualizations of economic vulnerability, we investigate the effects of individual low labour income and perceived financial strain on mental well-being. We argue that economic vulnerability restricts workers' agency and propose sense of control as a mediator in the relationship between economic vulnerability and mental well-being-irrespective of the household's financial situation. Multilevel analyses across 19 years based on a sample of N = 7,107 employed adults from the German Socioeconomic Panel (SOEP) demonstrated that a) persons reporting low income and higher financial strain showed lower health and life satisfaction, and b) intra-individual changes in income and financial strain were associated with corresponding changes in mental health and life satisfaction, respectively. These relationships were mediated by sense of control, both on the between-and the within-person level. The findings emphasize the importance of individual income and financial strain for mental well-being, and underline sense of control as an important psychological mechanism explaining individual consequences of economic vulnerability.