This article considers how trends in financing are changing governance at intergovernmental organizations (IGOs). Over the course of the twentieth century IGO funding rules changed in two important ways. First, they were altered to allow states greater control over the financial contributions they provide, allowing states to ‘earmark’ contributions. Second, funding rules made private actors eligible contributors, providing an important entry point for private actor influence. I focus on three primary effects of these changes on IGO governance: (1) how the increased reliance on earmarked contributions undermines traditional conceptions of multilateral governance; (2) how private actors are empowered by their ability to earmark resources as they emerge as major funders; and (3) on the surge in ‘minilateral’ governance associated with the rise of pooled funding mechanisms. I draw on delegation theory to illustrate these changes conceptually and provide examples from a wide variety of institutions within and outside the UN system. I conclude by outlining fruitful avenues for research on financing IGOs.