Compared to residential and commercial buildings, hotels use a high amount of resources in their operation, particularly electricity, water and gas. Resource use in hotels is influenced by both hosts and guests, however initiatives to reduce consumption are typically initiated by the host. To improve the effectiveness of host requests aimed at guests to use less resources, it is important to understand how hotel guests contribute to overall consumption. This study assesses quantitative resource consumption and occupancy data from two Australian case study hotels and investigates the impact of guest occupancy on net resource use. Agency theory is adopted as a framework to examine the host (principle) – guest (agent) exchange, and the agency costs associated with discretionary resource usage by the guest. It is found that guest numbers have little impact on net electricity consumption, however, are closely correlated with water consumption in both case studies. The findings suggest that strategies to reduce resource use are to be organised differently between electricity and water, with the former targeted at the hosts and the latter with the guests. Engaging with guests to reduce discretionary water consumption is expected to achieve greater reductions as compared to electricity and gas. The findings have implications for hotel operators and researchers toward designing and implementing effective resource use reduction strategies in hotels, and for understanding hotel resource use in the context of agency theory.