Hi @Seller_8WD90AQIKKxcQ,

Let me help clarify how FedEx billing works with Amazon Buy Shipping.

When you use Buy Shipping, FedEx won't charge your credit card directly. Instead, as mentioned in the "FedEx" section at Shipping services fees, the charges go to your Seller Central account - the same one where your selling fees are deducted. There's no extra per-transaction fee either.

There's just one exception: If you link your own FedEx shipper account to access your negotiated rates, then FedEx will bill you directly instead of through Amazon. You can find more details about this in the "Use FedEx through Amazon Buy Shipping" section at FedEx shipping services and restrictions.

Hope this helps! Let me know if you have any other questions.

Best regards, Michael