ABSTRACT The quality of delivery service encounters in which crowdsourced couriers and customers highly interact and mutually influence each other affects their attitudes and behaviours. Crowdsourced couriers and customers are bilateral users of crowdsourced logistics platforms whose loyalty determines the sustainability of platforms in a competitive environment. Due to the interdependence of couriers and customers in service encounters, this study utilizes the novel actor-partner interdependence model to investigate the impact of service encounter quality on courier and customer responses drawing upon emotion contagion theory. Dyadic analysis demonstrates that courier and customer perceptions of service encounter quality are positively related to their encounter satisfaction, with subsequent effects on loyalty (actor effects), and encounter satisfaction mediates the relationship between their perceptions of service encounter quality and loyalty. Notably, we show that customer encounter satisfaction is not only influenced by their own perception of service encounter quality but also by the corresponding courier’s emotional contagion through interaction (partner effects). This study provides valuable insights for practitioners of crowdsourcing logistics platforms to improve the quality of future service encounters.