This paper aims to highlight the relevance of institutional completeness as a conceptual and theoretical tool by applying it to an under-studied context: the cultural security of Han linguistic minorities in the greater Chinese-speaking region. By focusing on the Hakka minority in Hong Kong and Taiwan, it aims notably to exemplify how different institutional landscapes have contributed to create or reshape some identity categories, to politicize or depoliticize them, and to shift perceptions of security and insecurity toward different identity and institutional categories. In Hong Kong, nativist movements are increasingly inclined to conceptualize Hong Kong as a national minority of China in search of autonomy, and have focused on the strengthening of its majority language—Cantonese—at the expense of Hakka. Whereas in Taiwan, language revivalists have internalized the independence of their state, whose territory is still claimed by China, and have recognized its multilingual and multicultural makeup. They even recognize, albeit implicitly, institutional completeness as a solution to the language shift from minority languages, in particular Hakka and aboriginal languages, to Mandarin. This paper relates those processes by analyzing the diverse conceptualizations, practices, and politics of institutional completeness in the greater Chinese-speaking region, and tries to draw lessons that can be generalized to other linguistic and institutional settings.