Most businesses have unique shipping needs that are based on a variety of factors and limitations. Once the Merchant has decided which methods (and/or carriers) to offer, the only thing shoppers need to do is choose a method when they place their orders. As part of the third-party fulfillment setup process a mapping must be created from each available shipping description offered in the e-commerce system to the unique shipping code used by the fulfillment center.
To setup shipping methods in BigCommerce:
From with in BigCommerce, Click on Setup & Tools > Shipping
Click on Edit for the Zone of choice
Click on Edit next to the shipping charges types that have been setup. eg. Fedex or UPS
Specify the information and select the service types that will be applicable. eg. Standard Overnight, First Overnight etc.