Feedback mechanisms, such as customer reviews and ratings, are essential for making informed decisions on online platforms, particularly in the presence of asymmetric information. However, the practice of reward‐based reviews is on the rise in online platforms, where sellers incentivise buyers to give biased feedback (e.g., 5‐star ratings) regardless of the quality of the products. This study intends to determine whether financial incentives motivate people to award dishonest ratings and explore the moral heuristics underlying this motivation. Using a hypothetical purchase scenario, responses were elicited from 411 participants and the Philosophical Moral Framework Measure (PMFM) was used to identify the moral frameworks that underlie the reported self‐interested behaviour. The findings reveal that the likelihood of giving fake reviews increases with an increase in financial incentives. The dominant moral framework of those who accepted the cashback offer is utilitarianism and egoism, whereas those who declined the offer primarily have deontology and virtue theory as dominant frameworks. The results also indicate that men and young individuals are more likely to give dishonest feedback. These findings not only advance the understanding of the interplay between financial incentives and self‐interested behaviour but also aid in identifying the moral frameworks underlying self‐interested behaviour.