You can cancel any unshipped order from your Manage orders page. After you cancel an order, Amazon will send an order cancellation email to the buyer.
Cancel one order
On the Manage Orders page, locate the order you want to cancel.
Click Cancel Order in the Action column.
On the Cancel Order page, select a Reason for Cancellation. You may also enter any information you want to keep track of in the Seller memo field.
Cancel multiple orders
You can also cancel multiple orders using one of the following techniques:
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
Occasionally, you may need to cancel 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:
Dispatch and confirm all the order items that you can fulfil.
Use an Order Adjustment Feed to submit a refund for the order items that you cannot fulfil. Provide the following information in the feed:
Quantity Cancelled: The quantity that cannot be fulfilled.
Adjustment Reason: The refund code. Select either "NoInventory" or "CustomerCancel."