It's rare, but occasionally a merchant fails to use the buyer's prepaid label. If that happens and you get billed for shipping, you should request reimbursement from the buyer. This is easy to do via our site and the buyer has already agreed to reimburse you. You can Request Reimbursement using the button on the right side of each completed order screen in the My Account > Sold area. Write a short note to the buyer and enter the amount they owe you. Once the buyer pays, those funds will deposit directly to your WePay account. You can read more about our reimbursement system here.
