In the early 1920s, Hubert Llewellyn Smith took the lead in developing a new framework for multilateral trade policy in the Economic Committee of the League of Nations. He integrated the existing bilateral treaty regime into the League by imposing new forms of international oversight and standardization – most notably by codifying the most-favoured-nation norm. He also crafted a new rule-making routine to support the development of standalone multilateral agreements on key topics such as customs administration. Llewellyn Smith worked hard to preserve the status of the British Empire as an autonomous but segmented sub-unit within the League but he also understood that doing so would constrain Britain’s leadership capacity. Consequently, he aired on the side of caution, seeking consensus, working incrementally, and avoiding bold provocation. His limited ambitions allowed him to focus on crafting a new multilateral process, with important consequences for the subsequent history of international trade policy in the interwar period and beyond.