This article explores the discursive and practical entanglements of women’s work and sex trafficking, in Britain and internationally, in the early twentieth century. It examines discussions about trafficking and women’s work during a period that was instrumental in codifying modern, international conceptions of ‘trafficking’ and argues that porous and faulty borders were drawn between sex work, women’s licit work, and their sexual exploitation and their exploitation as workers. These borders were at their thinnest in discussions about two very important sectors of female-dominated migrant labour: domestic and care work, and work in the entertainment industry. The anti-trafficking movement, the international labour movement, and the makers of national laws and policies, attempted to separate sexual labour from other forms of labour. In doing so, they wilfully ignored or suppressed moments when they obviously intersected, and downplayed the role of other exploited and badly-paid licit work that sustained the global economy. But these attempts were rarely successful: despite the careful navigations of international and British officials, work continued to find its way back into discussions of sex trafficking, and sex trafficking remained entangled with the realities of women’s work.