postal savings system
英[ˈpəʊstəl ˈseiviŋz ˈsistəm]美[ˈpostəl ˈsevɪŋz ˈsɪstəm]
Many nations' post offices operated or continue to operate postal savings systems to provide depositors who do not have access to banks a safe, convenient method to save money and to promote saving among the poor.