Based on the case of a Belgian meat processing company that relies on posted workers employed by two subcontractors, this study investigates how posting affects client capital’s ability to control labour. Analysed through a Labour Process Theory lens, the findings reveal that posting fragments capital and substantially reduces the client firm’s control over workers’ effort and mobility power. This is due to the low-cost, temporary nature of posting, the disembeddedness of posted workers and their stronger relations with their employer than with the client firm. Competing to control posted labour, both units of capital enact practices commonly associated with trade unions: client capital advocates for posted workers in its interactions with the subcontractor, and the subcontractor promotes posted workers’ reduction of effort and increased mobility against the interests of client capital. Because of their structural vulnerability, posted workers might leverage conflicts within capital to resist the harshest forms of exploitation.