Research into the influence of affect on impulse buying has to date produced contradictory results, partly due to confusion between the potentially discrete influences of, respectively, state and trait affect. Additionally, studies on how the five-factor personality model’s dimensions influence impulse buying have also produced contradictory results. Moreover, while the established link between trait affect and personality suggests dimensions of this latter could account for whatever influence the former has on impulse buying, no study has yet attempted to examine this possibility. We draw on self-regulation theory to examine three unanswered questions: (1) the extent to which trait affect influences impulse buying whilst controlling for state affect; (2) establish which dimensions of the five-factor personality model predict impulse buying; and (3) test whether or not any influence of trait affect on impulse buying is additive to the effects of the five-factor personality model. Analyses of cross-sectional data (n = 842) find that trait affect does have a significant (p < .05) influence on impulse buying controlling for state affect, but that this influence is fully accounted for by the five-factor personality model (p < .001), the extraversion, conscientiousness and neuroticism dimensions of which are found consistently to predict impulse buying.