The conceptualization of policy change has been much discussed in democratic countries with a focus on formal legislation. However, in non-Western contexts, policies change in both formal and informal ways, and these informal mechanisms are challenging to observe. To fill this gap, this article uses the case of China’s policy process, where soft law policies play an increasingly important role in driving policy change. Drawing inspiration from legalization theory in international law, the article creates a novel typology of soft law policies based on dimensions of obligation and enforcement. Next, it compiles and analyzes a unique dataset of soft law policies from the central, provincial, and prefectural governments during the process of Household Registration (Hukou) System reform from 2011 to 2021. The results show that when the central government strengthens the obligation or enforcement dimension of the Hukou reform policy, then provincial and prefectural governments largely follow this policy change. Still, significant variations exist across provinces and prefectures in how they adapt to central policies. The findings highlight the potential of the typology of soft law policies to generate new insights into policy changes across China’s multi-level governance system.