ABSTRACTLoyalty programmes (LPs, thereafter) can restrict customers' actions where they require customers to undertake specific activities (i.e., LP efforts) to collect reward points. As a consequence, these activities inevitably limit customers' future consumption freedom. The customer's consumption freedom may be even more restricted by green loyalty programmes (GLPs, thereafter), given the pro‐environmental goals of such programmes. However, in order to attract customers to join a GLP, they may be offered rewards that are non‐eco‐friendly alongside eco‐friendly ones. If customers choose non‐eco‐friendly rewards, then this can defeat the pro‐environmental objective of offering GLPs to customers. This study focuses on the effect of individual differences in trait reactance on reward preferences in GLPs that has been overlooked in LP literature. Through one experimental study and three scenario‐based online surveys, we find that customers with high (vs low) trait reactance are more likely to choose the non‐eco‐friendly rewards. However, when customers are primed with the pro‐environmental goal, they choose eco‐friendly instead of non‐eco‐friendly rewards. Interestingly, we find that this effect is stronger for those who score highly on trait reactance. Our research advances the understanding of LPs and psychological reactance theory, highlighting the broader implications of studying reactance in managing customers' preferences for GLP rewards. We explore how high‐reactant LP members, when their pro‐environmental goals are salient, respond positively to offerings by preferring eco‐friendly rewards. This demonstrates the superiority of the goal‐reward congruity hypothesis over the effort‐reward congruity hypothesis, enriching previous studies on goals and pro‐environmental behaviour. Moreover, the insights gained from this study have practical implications for designing effective reward schemes that promote pro‐environmental behaviours.