You can cancel any unshipped items or orders from your Manage orders page. After you cancel an item or order, Amazon will send a cancellation email to the buyer.
Cancel one order
Cancel multiple orders
You can also cancel multiple orders using one of the following techniques:
Note: We expect sellers to maintain accurate inventory levels. Failure to adjust your inventory in a timely manner can lead to excessive pre-fulfilment order cancellations. For information on how we factor cancelled orders into your overall performance, see Customer Metrics.
Partial refunds
Occasionally, you may need to cancel an part of an order with multiple items and refund the items that are cancelled. If you manage your orders using inventory files, you can upload an Order Adjustment Feed.
To cancel or refund part of a multi-item order, follow these steps:
For more information, see Refund or Partially Cancel Orders—Order Adjustment or Partial Cancellation.