Why do firms reactivate previously broken relations with other firms? We explore why this happens, or doesn’t, in a customer-supplier context. Research on business relationships has focused primarily on the formation, maintenance and dissolution of ties. In contrast, we present a model and qualitative data on reactivation processes. Our theoretical framework focuses on a set of foundational elements, namely, trust, reliability, and uncertainty, as well as a set of catalytic activators to explain the occurrence of reactivations. Based on data from 83 in-depth, open-ended interviews with executives of twenty-two Scandinavian firms, we show that, if a positive relational context still exists, reactivation is often triggered by a critical event such as a reorganization or acquisition. We also show that reactivation can be remarkably beneficial for both firms; unlike newly-initiated ties, reactivated ties typically benefit from many relational qualities that the firms had established in their previous interactions.