In this article, the author advances understandings of the coloniality of British citizenship through the close examination of the status of the people of Hong Kong in Britain’s immigration and nationality legislation. This is a case that has been overlooked in most social scientific analysis of Britain’s citizenship–migration nexus. The article responds to Gurminder Bhambra’s call to recognise the connected sociologies and histories of citizenship, and the analysis is informed by the close reading of historical changes in legislation – from decolonisation and the making of the British nation-state to the post-Brexit construction of ‘Global Britain’ – and what these have meant for the people of Hong Kong. In dialogue with scholarship focused on the enduring colonial ties in present-day citizenship and migration regimes, the article offers an analysis inspired by Manuela Boatcă’s coloniality of citizenship and Ann Laura Stoler’s understanding of exception by design: imperial forms of governance producing differential rights within national populations that position some populations as ambiguous. Conceptualising the status of Hong Kongers in British legislation past and present as ambiguous by design, the author questions what the rhetoric of the Hong Kongers as ‘good migrants’ for ‘Global Britain’, the narrative at the heart of the promotion of the bespoke Hong Kong British Nationals (Overseas) (HK BN(O)) visa launched in early 2021, conceals from view. As the author argues, rather than a case apart in the context of increasingly restrictive immigration controls, the renewal of Britain’s obligations, commitments and responsibilities to the people of Hong Kong through this visa scheme provides further evidence of the enduring colonial entanglements in the formation of ‘Global Britain’ and its citizenship–migration nexus.