In this article, which is based on research conducted in Hong Kong from 2010 to 2013, and again in 2018, I analyse the region-bound circulation of independent women sex workers from the Philippines across the Asian global cities of Hong Kong, Singapore, Kuala Lumpur, and Macau. Migrating as visa-free tourists, they maintain a valid immigration status and maximize their income in the informal economy by adopting a step-down transient mobility pattern characterized by a downward hierarchical circulation to multiple city-states and country destinations. As I show, their multinational migration is produced and structured through the instrumentalization of a mobility infrastructure constituted by a regime of visa-free circulation, transportation developments, commercialized migration services, and social networks. In this article, I attempt to extend the contemporary analysis of unauthorized migration by moving away from the prevailing focus on incorporation and settlement and towards an examination of the logics and mechanics of migration flows that occur outside state-sanctioned channels.