Retail self-service checkouts (SCOs) can benefit consumers and retailers, providing control and autonomy to shoppers independent from staff. Recent research indicates that the lack of presence of staff may provide the opportunity for consumers to behave dishonestly. This study examined whether a social presence in the form of visual, humanlike SCO interface agents had an effect on dishonest user behaviour. Using a simulated SCO scenario, participants experienced various dilemmas in which they could financially benefit themselves undeservedly. We hypothesised that a humanlike social presence integrated within the checkout screen would receive more attention and result in fewer instances of dishonesty compared to a less humanlike agent. Our hypotheses were partially supported by the results. We conclude that companies adopting self-service technology may consider the implementation of social presence to support ethical consumer behaviour, but that more research is required to explore the mixed findings in the current study.