Abstract: Disclosure-based Nudges are being increasingly utilized by governments around the world to achieve policy goals related to health, safety, employment, environmental protection, retirement savings, credit, debt and more. And, yet, a critical aspect of these Nudge-type policy interventions—the mode of communication—remains unexplored. What is the best way to communicate information to individuals—by letter, by phone call (or voice message), by email, by text message or video message? We begin to answer this basic question using a real-world policy experiment on debt collection procedures. Debtors often lack adequate information about the debt, the judgment, and the enforcement and collection procedures. As a result, the process of debt collection is often harmful to the debtor and ineffective in securing repayment. We conducted a study (N = 36,362), in cooperation with the Israeli Ministry of Justice, to improve communication with debtors and to evaluate the effect of such improved communication strategies on collection procedures and outcomes. A novelty of this study is our focus on the choice of medium—telephone, regular mail, text message and video message—holding fixed the content of the communication. We found that digital communication strategies, specifically communicating via text message, were the most cost-effective, significantly improving outcomes for both debtors and creditors. Our results should inform the choice of communication mediums in the many settings in which disclosure-based Nudge policies are employed.