Consensus moderation, where collaboration and discussion take place to reach an agreement on mark allocation, is a frequently used approach to quality assurance in higher education. This study explored expert academics' perceptions of consensus moderation through 12 semi-structured open-ended interviews. Data were analysed using thematic analysis and resulted in six themes: accept that marking is subjective; consensus moderation is a learning process; use calibration to develop and maintain standards; moderation is core academic work; resources are needed to enable consensus moderation; and different moderation practices are needed for different moderation purposes. Consensus moderation is a complex activity with many challenges, and the findings from this study contribute to our current understanding of consensus moderation. The findings have implications for policy and practice, and have identified ways in which we can enhance consensus moderation practice.