Abstract: A complex order processing system is implemented in an architecture that allows customer service representatives and customers to access the customer's accounts, service profiles, quotes, and orders. Account information can be entered and updated. Quotes can be generated for various configurations of products and services having different types of charges including one time fees, recurring fixed fees, and usage-based fees. The quotes can be saved, and later updated by the customer or by the system to reflect changes in the configuration of a product or service that is included in the quote. The quote can be converted to an order, and pending orders can be modified. Before allowing modification of a quote or order, the requested future state of a product or service is created by applying the prior active and unprocessed orders to the product or service. The portion of the product or service currently selected is also applied to the product or service, and the user can then reconfigure the product or service.