Settings > Shipping Overview is a complete list of your accounts. Here, you’ll assign the Shipping Carriers you’ve set up to specific smart lists or to your ‘Whole Inventory’ and by fulfillment method: Merchant Fulfilled or FBA.
To manage the Shipping Carriers for an account, select the account and use the ‘+’ and ‘-’ buttons to add or remove rules.
You can drag and drop rows to reorder the list but please keep in mind that you must put ‘Whole Inventory’ last.
You can edit existing Shipping Carriers here by clicking the 'edit' option to the right of the carrier name.