Over the last century, the South African state has periodically engaged in the practice of 'exempting' various migrants from their otherwise irregular immigration statuses. Always backed by official legislation, exemptions represent one way by which dominant capitalist interests have relied on the legitimacy of the state to meet their labour needs by sometimes employing undocumented migrants from the Southern African region. Through insights from sub-imperialism and bordering, this paper discusses historical case examples from policy articulations, parliamentary debates, secondary literature and archival materials. By exploring cross-national relationships of exploitation and differentiation, the paper argues that exemptions should be understood as attempts by which the contradictions of ubiquitous informal cross-border mobility and employment in a regime of unfree regional movement might be resolved. Exemptions also attest to the challenge of governing human mobility in a region invested with a historically vast infrastructure of producing, attracting as well as exploiting cheap migrant labour.