A method allowing a customer to define its telephone service within flexible boundaries for calls directed to the customer. Within constraints imposed by the selected embodiment, the method reduces software development traditionally associated with the provision of new services. A plurality of independent call processing capabilities, such as announcement, digit collection, billing, etc., are provided at a switching office. A program defined by a customer is executed in response to each call to the customer. The program makes decisions based on the parameters of the call, such as time, ANI, information digits requested and received from the caller, etc., and links together the appropriate ones of the capabilities in the proper order to dispose of the call based on the call parameters as specified in the program. A customer service may be modified by changing the customer program.