China and other so-called “emerging” donors and creditors are fundamentally changing the international development finance landscape; however, many of these actors do not participate in existing global reporting systems, such as the OECD’s Creditor Reporting System (CRS) and the International Aid Transparency Initiative (IATI). To address this challenge and help those who seek to understand the nature, distribution, and effects of development finance from emerging donors and creditors, AidData developed the Tracking Underreported Financial Flows (TUFF) in collaboration with an international network of researchers from Harvard University, Heidelberg University, the University of Göttingen, the University of Cape Town, Brigham Young University, and William and Mary. The methodology codifies a systematic, transparent, and replicable set of procedures that facilitate the collection of information about aid and credit from official sector donors and lenders who do not publish comprehensive or detailed information about their overseas activities. It does so by synthesizing and standardizing vast amounts of unstructured, open-source, project-level information published by governments, intergovernmental organizations, companies, nongovernmental organizations, journalists, and research institutions.