Customer Voice Behavior: A Systematic Review and Future Research Agenda

ABSTRACT Customer voice behavior (CVB) is increasingly recognized as a means for consumers to influence firms by offering valuable insights for product and service improvements. Yet, knowledge of the concept remains fragmented, with limited integration between complaint‐oriented and proactive perspectives. This study systematically reviews 80 peer‐reviewed articles published between 1987 and 2024 to clarify how CVB has been defined, conceptualized, and examined. Using the Theories, Contexts, Characteristics, and Methods (TCCM) framework, the review identifies key theoretical lenses, research contexts, methodological trends, and conceptual inconsistencies. The analysis reveals a gradual shift from reactive complaint behavior to proactive, extra‐role expressions of voice, while also noting definitional inconsistencies and limited research attention to the extra‐role perspective. Building on these insights, the study proposes an integrated conceptual taxonomy that bridges complaint behavior and extra‐role behavior, offering a clearer structure and sharper conceptual boundaries for CVB in the consumer behavior literature. Finally, practical implications are discussed, guiding firms seeking to harness customer voice not only for service recovery but also for innovation and long‐term engagement.