The book presents the results of several qualitative research project with different actors that put migration policies into practice. It shows the different ways in which day-to-day activities of organisations shape migration policies on the ground. This book offers a comprehensive exploration on how different migration policies are implemented day by day. Such an approach allows to show the different ways in which migration policies on the ground take a life of their own when compared to the letter of the law. The book shows the need to understand the specific logics and workings of the implementation of policies, while taking into account the continued role played by politicians and the judiciary, non-state actors and migrants. Qualitative research with different public institutions implementing migration policies are combined with an exploration of the role of NGOs, supranational institutions and the migrants themselves. Bringing together the results of several research projects with fieldwork in Belgium, the UK, France, Morocco and Malta, the book covers the different stages of the migratory career. It follows the potential trajectory of a migrant from visa obtention (both in general and for students specifically) to border controls, asylum (including resettlement and gender and sexuality-based asylum), access to residence (with a specific focus on marriage-based residence), healthcare and nationality, or to detention and managed return migration. Through its chapters it shows the day-to-day logics, routines and tactics that bureaucrats and other actors adopt, within the constrains of laws, social interactions, and ideas about policies.̀A PROPOS DES AUTEURSDjordje Sredanovic est charǵe de recherche F.R.S.-FNRS au laboratoire GERME de l'Universit́e Libre de Bruxelles. Sociologue sṕecialiśe dans les ́etudes de la nationalit́e, citoyennet́e et migrations, il a conduit recherches sur les exṕeriences et l'impĺementation des politiques migratoires.Federica Infantino est Marie Sklodowska-Curie Fellow au Migration Policy Centre ̀a l'Institut Universitaire Euroṕeen ̀a Florence est Maitre de Conf́erence ̀a l'Universit́e Libre de Bruxelles.