Large-scale corporate fraud often evolves from the intricate, coordinated actions of several individuals. Despite being a pivotal aspect of human cooperation, only few studies within the field of collaborative dishonesty have included communication between participants, and no studies have yet experimentally compared this to non-communicative contexts. As a result, the impact of communication on unethical collaborations remains unclear. To address this gap, we conducted two well-powered studies (Ntotal = 1,187), closely replicating and extending seminal research by Weisel and Shalvi (2015), introducing communication as a manipulated variable within a dyadic cheating task. Across both studies, we found compelling evidence that communication increases the magnitude of cheating – even when coordination on the task is not allowed. Importantly, the effect of communication was linked to a stronger experienced collaboration among the communicating dyads, highlighting that communication is not only key to everyday ethically sound collaborations, but also to corrupt collaborations.