In modern society, smartphones are widely used throughout the world, and little is known about the predictors of smartphone addiction in the daily working context. Our two-week experience-sampling study of 138 teachers revealed that incivility as a work stressor influences smartphone addiction through work-to-family conflict. We further examined the daily-level relationship between smartphone dependence and insomnia. The results showed that incivility from students, instead of coworkers, is positively correlated with work-to-family conflict, which in turn influences individuals’ temporary smartphone dependence; lack of control moderates the relationship between work-to-family conflict and temporary smartphone dependence; and phone dependence is positively associated with insomnia. Our findings enrich compensatory internet use theory and the Interaction of Person-Affect-Cognition-Execution (I-PACE) model and expand the smartphone dependence research to the working area.