A database report writer and customer data management system and method provides a GUI type interface to allow users convenient on-line access, such as via the Internet, to customer billing and inventory data in the form of an on-line report. The present invention facilitates on-line creation of report definitions which specify desired data to be produced in a report, and other parameters relating to display, sorting, accounting, grouping, and filtering of report information. The present invention also allows users to create custom database tables and input their own data for display in reports along with billing and inventory data. As a result, the present invention provides the ability to eliminate conventional hardcopy reports typically produced in the form of a billing statement.