Why do I see cancelled orders on the Manage orders page?

Although no action is possible on cancelled orders, Amazon provides sellers with basic details about these orders so that you will have a complete record of buying activity for your items and the ability to manage your sales and inventory levels effectively.

Canceled orders are “complete” as the “pending” stage is resolved. While some orders are cancelled by a buyer before they enter the processing stage, other orders are cancelled by Amazon after hours or days of processing. You can correspond with a buyer until their order is cancelled. If the buyer has questions after their order is cancelled, direct them to Amazon customer service.