How do I deleted unused or unwanted Shipping Rates?
Available Shipping Methods per Shipping Zone are defined at Edit Shipping (Page 3 or Page 7, depnding on your configuration). If a previously available Shipping Method is removed on that screen (by selecting None in the "Avail" select box), any associated Shipping Rates are deleted. Shipping Rates are also deleted if a fundamental change is made the the way in which Shipping Rates are specified, such as a change in the Shipping Cost Calculation method specifed on Edit Shipping (Page 1). These options are available at Settings/Shipping in the Order Management System.