预付费退货运输承运人
作为加入亚马逊预付费退货标签计划的卖家，除了亚马逊的条款和条件之外，您还需要同意承运人的条件。
UPS 和 USPS 可通过购买配送为卖家自配送订单提供所有退货运输服务。使用购买配送，即表示您确认并同意遵守您购买的退货配送将受适用承运人或服务提供商的条款和条件约束和管制：
UPS 条款和条件
USPS 条款和条件
USPS 平邮将配送重量不超过 1 磅的大部分商品。UPS 陆运将配送重量为 1-150 磅的商品。
注意： 作为包裹计费重量的衡量标准，如果包裹的实际重量超过 150 磅，或者长度超过 108 英寸，或长度与围度 [（2 x 宽度）+（2 x 高度）] 之和超过 165 英寸，亚马逊将不会运输此类包裹。此类包裹不应收到亚马逊生成的预付费标签。请参阅卖家自配送退货的运费，了解每个重量分段的退货运费。
重要： 当买家发出商品后，亚马逊将从您的卖家账户扣除退货运费。有关如何在发放退款时处理退货运费的详细信息，请访问退还运费。
亚马逊官网原文详情：
Prepaid return shipping carriers
As a seller in the Amazon Prepaid Return Label Program, in addition to Amazon's terms and conditions, you are required to agree to the carriers’ conditions.
UPS and USPS provide all return shipping for Seller Fulfilled Orders through Buy Shipping services. By using Buy Shipping services, you acknowledge and agree that your purchase of return shipping is governed by and subject to the terms and conditions of the applicable carrier or service provider:
UPS Terms and Conditions
USPS Terms and Conditions
USPS First Class mail will ship most items under one lb. UPS Ground will ship items between 1-150 lbs.
Note: Packages with an actual weight of more than 150 lbs, or that exceeding 108 inches in length, or exceeding a total of 165 inches in length and girth [(2 x width) + (2 x height)] combined, as measured to determine their billable weight, are not accepted for transportation. They should not receive an Amazon-generated prepaid label. See Shipping costs for seller fulfilled returns for the cost of return shipments in each weight band.
Important: Amazon will charge your seller account for the cost of the return shipping once the customer ships the product. For details on how to handle return shipping cost when issuing refund, visit Refunding shipping cost.
文章来源：亚马逊官方网站
