Summary: This Global Detention Project Working Paper details how the banalisation of immigration detention is contested by international human rights mechanisms. Since the creation of the United Nations, the global human rights regime has provided a framework for the protection of all people, including those living in foreign countries. This paper assesses how national sovereignty and access to territory is mitigated by the universal nature and applicability of human rights and refugee protection standards. The authors comprehensively describe the normative framework governing immigration detention established in core international treaties and discuss how human rights bodies apply this framework when reviewing states’ policies and practices. Their assessment of the impact and implementation of fundamental norms reveals gaps in the international protection regime and highlights how states’ responses to this regime have shaped contemporary immigration detention systems.