In the British Empire, much printed matter originated from outside the colony and was funneled through port cities, where customs checked the material to see that it was not pirated, obscene, or seditious. Customs and Excise hence became the section of the colonial state responsible for copyright. However, their task was not straightforward since officials faced a tangle of colonial, imperial, and international legislation. Unable to work out which law applied where, customs officials elaborated their own practices, which they generated from their daily routines. Any understanding of copyright hence requires a focus on the dockside politics of customs and how notions of copyright emerged from these practices. Taking southern Africa as a case study broadly representative of white settler colonies in the British Empire, the article explores the workings of customs and its implications for new interpretations of copyright.