The present invention provides a computer system (the "System", or the "Return System") that is configured and programmed to provide online stores with a fast, simple, convenient way for eCommerce customers of an online store to return merchandise purchased from that store from within that online store. The Return System provides multi-carrier shipment rating, shipment labeling, shipment tracking, shipment tracking management reports, returns analysis and returns management reporting In an exemplary embodiment, the Return System has three major components: 1.) A Returns Manager Subsystem that provides a user interface to each Merchant to setup the Merchant's account, setup the Merchant's return policy and rules, and to monitor the status and movement of return shipments; 2.) A Consumer Returns Subsystem (also sometimes referred to as a "Customer Returns Subsystem") that provides each consumer using the Returns System with an online user interface that leads the consumer through the returns process, displays the return policies and rules to the consumer, provides shipping document to ship the return package if appropriate, and permits the consumer to track their return shipments; and 3.) a Returns Processing Subsystem that, in the exemplary embodiment, provides background shipping and tracking functionality. In one exemplary embodiment of the present invention, the Online Merchant integrates the Merchant's online system with the Returns Processing Subsystem. In another exemplary embodiment, the Returns Processing Subsystem is provided as an independent web-based application service (referred to as a "Return Merchant Service System") operated by a common provider. In such an embodiment, the Merchant's system interacts with the Return Merchant Service System through Application Program Interfaces ("API").