A system and method for verifying charges on a customer bill includes a computers for downloading, from a mainframe computer, to a local server billing data associated with a customer account, populating a database with a portion of the billing data, performing pre-calculation functions on another portion of the billing data and populating the database with results of the pre-calculation functions, displaying predetermined categories of information stored in the database, calculating the taxes for each of several charges in the billing data and storing tax results in the database, and comparing the tax results with tax information on the customer bill.