Conventional wisdom holds that colonial trading relations were a one-way street: trade policy coerced colonies to export raw materials to the metropole and in turn purchase large quantities of manufactured goods from the empire’s industrial centers, thus hamstringing local industries. We argue that this narrative overlooks a critical feature of interwar history: the devolution of limited representation to key colonies. Self-government created an avenue for manufacturers in colonies to register their preferences over preferential trade policy, providing a new bulwark against imperial commercial exploitation. We theorize that the extension of limited franchise markedly altered trading relations between metropoles and colonies — specifically, by endowing colonial parliaments with trade policy authority. We evaluate this claim through a deep examination of trade policymaking in British India. Using an original dataset of all product-level import tariffs in India from 1904 to 1950, as well as archival records of local legislative debates and confidential correspondence, we show that incipient democracy eroded Britain’s ability to shape India’s tariff policy to suit British manufacturers’ needs. The introduction of a limited franchise shifted the balance of power in trade policy from British to Indian interests, illustrating how electoral autonomy reduced the rapacity of colonial power.