["The British Journal of Sociology, EarlyView. ", "\nABSTRACT\nBased on ethnographic fieldwork among Congolese traders operating in Kinshasa's urban economy, this article examines how differentiated family ties and wealth transmission shape social mobility and the intergenerational reproduction of inequality. We show that family support is neither uniform nor equally productive: its effects depend on both class position and the specific relationships mobilised. While assistance among siblings and extended kin is widespread, it tends to remain modest and short‐lived, supporting entry into trade or crisis management rather than sustained accumulation. By contrast, marital and intergenerational ties more often enable threshold‐crossing mobility by providing access to larger volumes of capital, protective connections, and resources for children's education, business developments, and migration trajectories. We argue that these unequal forms of intra‐family wealth transmission contribute to the durability of class positions across generations.\n"]