This brief aims to demonstrate that the Employment Permit System Act which restricts labour mobility of migrant workers and its inflexibility places migrant workers in a particularly vulnerable position and provides employers with the opportunity to exert disproportionate power over them resulting in discrimination and other abuses. This brief also aims to demonstrate how this lack of labour mobility is a major reason for migrant workers being subjected to human rights abuses, in violation of South Korea’s international legal obligations under human and labour rights treaties.