Why is the signature fee does not include in the FedEx shipping rate but billing adjusted later ?
"I did select a signature service the time I created my FedEx label, but the fee does not include in the rate quote, but the billing adjusted later, is it a system bug?"
In this scenario, the client selects a signature service for the shipment, and when the client creates the label with FedEx service, the signature charge is not included in the rate quote, yet, the signature fee was added to the shipment later in the billing adjustment, why does this happen?
This is not a system bug, it is because the official API document for the Billing on shipment does not include the signature service, but the official API documentation for the generating shipment does include the signature service charge; therefore even though the signature fee does not include in the rate quote, but there is an actual signature fee generated if signature service is selected. The signature service fee will be adjusted through billing adjustment when FedEx has billed the shipment.
Billing API Documentation
Rate Quote API Documentation