Herein, we describe the discovery and development of a method to exchange the counteranion component of diaryliodonium salts, which is a critical step for their use in chemical synthesis. The method involves a reusable and readily available solid-phase column assembled from common laboratory consumables. This process avoids challenging product separation associated with other methods for anion metathesis of diaryliodonium salts, and selected examples demonstrate the scope of the method. Hazard analysis (differential scanning calorimetry) on all salts used in this study revealed exotherm initiation temperature in the range of 139−199 °C and exotherm magnitude of 60−845 J/g for a single peak.