Due to increased competition in the utility industry, it is becoming essential to know not only who your customers are, but where they are. Utilities need AM/FM applications to respond quickly when customers change their load, are out of service, or are pursued by competitors. At Ohio Edison the essential component of these applications is a link to the legacy Customer Information System (CIS). This paper will explore planned applications relying on the CIS link. It will then address problems encountered building the link, solutions used to correct existing converted data, actions taken for future conversion, and finally issues involved in maintaining the link. The paper will not delve deeply into applications or platform, but will discuss, in general terms, the process of developing and maintaining the a link between a GIS and a legacy CIS through conversion.