The overall aim of this thesis is to provide an holistic assessment of the financial practices of migrants in advanced Western economies using the analytical lens of risk. More specifically, this research argues that a geographical approach to risk, informed by concerns about time, space and place, is key to understand the full complexities of migrants’ financial decision‐making. In so doing, this research contributes to an emerging body of work that recognises the need for a more nuanced understanding of migrants’ engagement with the formal and informal financial sectors. The study draws on a mixed‐methods research design, which includes 60 in‐depth interviews and 53 structured questionnaire interviews with Congolese and Francophone Cameroonian migrants in London. Empirically, the project explores the formal and informal financial practices of the research participants in relation to banking, savings, credit, debt management, insurance as well as remittance sending. In addition, it reviews the different levels and types of risks encountered by migrants in their everyday lives, and how these shape their financial decision‐making. The thesis develops a framework combining current thinking from risk research with transnational migration and economic geography scholarships in order to uncover the social and geographical embeddedness of migrants’ financial decision‐making. It shows how the risks of financial hardship managed through migration actually evolve across space and time so that some migrants find themselves confronted by the very same risks of economic and social exclusion they sought to avoid by moving. Most noticeably, this research shows how such risks are managed by migrants through ‘mixing and matching’ a range of informal and formal financial practices whereby the costs of being financially excluded are balanced against, and shaped by, migration histories and experiences of living in a highly financialised and increasingly migrant‐averse society.