Relationships between firms and their foreign suppliers are the foundation of international trade, but data limitations and reliability concerns make studying such relationships challenging. We evaluate and enhance supplier information in U.S. import data and present new facts about importer–exporter relationships. Count of foreign exporters from U.S. import data tends to exceed those from source country data, especially from China. The pattern of U.S. imports from origin countries changes substantially by tracing trade back to the supplier's location instead. Related‐party relationships trade more, while larger countries have more relationships.