To help identify between BigCommerce Order and Shipment IDs, we required a 1 or 2 letter prefix to be attached to Shipment IDs in Shiptheory.
Shipment IDs in BigCommerce will not be changed, this is purely for display and purposes in Shiptheory.
The prefix must be either one or two letters long and will be attached to the beginning of all BigCommerce shipment, please note that it is not changeable once set.
You will be given the option to choose your shipment reference prefix when you set up your account, the default being "S".