Studies on migration and social protection have shown that a lack of access to formal welfare in receiving countries leads migrants to rely on their informal social networks for support. This paper argues that such clear-cut dichotomies between formal and informal social protection systems ignore the manners in which both welfare- state institutions and migrants work together at the interstices of the formal and informal to cater to national and transnational social protection needs. Based on empirical data collected during 14 months of multi-sited and partially matched-sample ethnography with Sudanese families across the Netherlands and Sudan, this paper investigates how migrants sometimes enter into symbiotic relationships with different welfare-state institutions, such as municipal offices, non-governmental organisations and other immigration institutions, which in turn rely on the support of these migrants to provide social protection to people who would otherwise escape their purview. While these interplays allow migrants, who are sometimes undocumented, to informally participate in the formal social protection system, such practices are embedded within power relationships that are at times risky, especially for migrants.