Compulsive buying (CB) has only relatively recently become a topic of interest for researchers and clinicians alike. This hiatus means that (unlike other impulse control disorders) there is currently little theoretical guidance for clinicians attempting to intervene with CB clients and no established model for researchers to evaluate, distil and refine. The current paper summarizes and organizes the main extant identified factors in the CB literature into four distinct phases: (1) antecedents; (2) internal/external triggers; (3) the act of buying; and finally, (4) post-purchase. The relationships and interactions between the identified phases are then hypothesized, within the proposed cognitive-behavioural model. The model distinguishes the key cognitive, affective and behavioural factors within each phase and identifies how CB can become self-reinforcing over time. The over-arching treatment implication is that CB can be re-conceptualized as chronic and repetitive failure in self-regulation efforts, and that psychological interventions can accommodate this in attempting to facilitate change. A successful case example is provided of a 'co-dependent compulsive buyer' using the model, with psychometric evaluation of key aspects of CB and mental health at assessment, termination and 6-month follow-up. The research and clinical implications of the proposed model are discussed, alongside identified short-comings and the need for psychological services to respond appropriately to CB clients seeking help.