A method of obtaining subscriber identification information using a subscriber number input by a customer calling a subscriber identification information service is provided. A switch recognizes a shortened telephone number provided by the customer and connects the customer to a peripheral network system. The customer provides the unrecognized subscriber number and the number is used to search a memory for corresponding subscriber identification information. If the information is available for the customer, the information is forwarded to the customer. If the information is unavailable for the customer, the customer is informed that the information is unavailable.