Objective Two studies investigated childhood maltreatment, alexithymia—the inability to identify one's mood—and negative mood regulation expectancies (NMRE)—confidence that one can alleviate one's negative moods—as predictors of compulsive buying (CB). Method Participants were recruited from internet CB forums and undergraduate psychology classes. Online, they completed questionnaires and a behavioral task that assessed impulsive spending. Results In Study 1 (N = 646), analyses indicated that NMRE, alexithymia, and childhood maltreatment were significant independent predictors of CB. For Study 2, a subset of participants from the Study 1 pool (N = 295) who met the criterion for clinical levels of CB were selected, based on their self‐report. Analyses revealed that NMRE buffered the effect of maltreatment: among participants with high NMRE—higher levels of maltreatment were associated with minimal increases in CB and impulsive spending behavior. Conclusion Being confident that one can control one's unpleasant moods was a protective factor from the maladaptive consequences of childhood maltreatment. Increasing NMRE early in psychotherapy for CB may result in clients' using more adaptive coping strategies.