From September 2016 to September 2018, we piloted the collection of financial transaction and account balance data in the Understanding America Study (UAS), a probability-based Internet panel representative of the U.S. adult population. Unlike previous studies relying on electronic transaction information from financial aggregators, which typically contain very little information on consumer characteristics, our data allow us to explore heterogeneity in consumer behavior as driven by demographics, cognitive ability, and financial literacy, among others. In this article, we describe the results of this pilot project, documenting selectivity issues and the major barriers associated with participation in the study. We carry out illustrative exercises to highlight how the combination of surveys and electronic financial records can lead to methodological advances in the measurement of individuals' spending and saving behavior.