This article examines the complex and ambivalent nature of the encounters between British volunteers and refugees within the 2015 Refugees Welcome movement. The 72 interviews we conducted with volunteers active in different charities and informal networks reveal the significance of the logic of trust in these encounters. We show that although participants often base their engagement on claims that disrupt dominant narratives about border controls, they also tend to endorse and reproduce bordering processes based on the perceived trustworthiness of refugees and, sometimes, exclude some groups from their support. Taking insights from the literature on encounters and critical humanitarianism, our article highlights from a theoretical and empirical perspective how “ordinary participants” in the refugee support sector can subvert humanitarian borders, but also participate in the construction of new types of borders based on domopolitics. More generally, the article aims to highlight civil society’s voluntary participation in the governance of migration.