This research examines how the implications of emotional labor can transfer from customer encounters to coworker interactions using temporally lagged data from a sample of frontline service employees. The results show that surface acting in customer service encounters is positively, and deep acting is negatively, related to ego depletion. Employees’ ego depletion, in turn, is positively associated with their interpersonally harmful behavior toward coworkers. Hence, ego depletion appears as a mediating variable that translates the implications of distinct emotional labor strategies into coworker harming. Moreover, emotion regulation self‐efficacy moderates the role of surface acting. The positive indirect relationship between surface acting and coworker harming, via ego depletion, is buffered among employees with higher emotion regulation self‐efficacy. These findings shed new light on the complex and far‐reaching consequences of emotional labor. We demonstrate the relevance of emotional labor to third parties not directly involved in customer service encounters and highlight important mediators and boundary conditions of these indirect relations.