The security-migration nexus is ubiquitous throughout Europe and beyond. An avalanche of scholarship has explored the construction of migration as a security threat in general and, in the UK, the creation of the ‘hostile environment’ in particular – the problematic nature of each being well documented. Yet, far less attention has been paid to activities that contest this process. Deploying Balzacq's four modalities of contestation – desecuritisation, resistance, emancipation, and resilience – this article addresses the imbalance, exploring how asylum and refugee sector NGOs engage in and contest security-migration politics. Using Scotland (2018–19) as an illustrative case and analysing discursive and predominantly non-discursive activities, findings demonstrate that NGOs are successfully contesting the security-migration nexus in Scotland across four principal categories, supporting the ‘surviving’ and ‘thriving’ of asylum seeker and refugee communities, problematising previous conceptualisations of ‘UK’ asylum and refugee politics, with implications extending globally. The article helps refine the theorisation of contestation, demonstrating first, the need to move beyond studies of ‘desecuritisation’, with consequences for understandings of ‘success’ in securitisation, and second, the potential blindness of single-modality studies to vital, meaningful contestation, resulting in the production of less comprehensive visions of the security world.