Accounts and Payments
I believe shipper is paying all charges
Payment options for FedEx shipments are completed on the International Airwaybill, in billing and payment section. Subject to the account information being completed correctly and the accounts stated being active at the time of billing, FedEx will bill according to these instructions.
If however these fields are not completed transportation charges will default to the shipper and any importation charges will be passed to the importer/recipient.