Digital retail payments have evolved during the last years mostly due to technology innovations. New actors enter the payments market, increase competition and threaten banks' dominance. Consumers' behavior is critical within this context, since they are the ones that 1 finally adopt or reject a payment innovation. In this paper we propose a model of consumer behavior towards payment system selection based on multi-agent simulation. It is based on a multi-agent platform that models' consumers as intelligent agents and formats their behavior according to the rules extracted from past payments data, experts' knowledge and marketing research. Contributions from the social science and network economics also refine the agent's behavior in order to simulate accurately the domain. This paper presents the overall model and an initial analysis of payments domain, defining major actors in the domain and their interpretation to agents.