This article examines the history of mining in British Southeast Asia during the early twentieth century. In particular, it focuses on the histories of the Burma Corporation and the Duff Development Company, which were located in British-occupied Burma and Malaya, respectively. It argues that despite being represented as “rogue” corporate ventures in areas under “indirect” colonial rule, the contrasting fates of each company—one successful, one not—reveal how foreign-owned businesses operating in the empire became increasingly beholden to British colonial state regulations during this period, marking a shift in policy from the “company-state” model that operated in prior centuries. The histories of these two firms ultimately demonstrate the continued significance of business in the making of empire during the late colonial period, bridging the divide between the age of company rule and the turn toward state-sponsored “development” that would occur in the mid-twentieth century.