In the event that you can't complete a sale, you may be penalised in the form of a fee or restrictions to your account until you have successfully completed it. Multiple cancelled sales can also result in StockX suspending your account. For more information, refer to our FAQ:
As a Seller, can I cancel a sale?
StockX offers incentives in the form of reduced fees for Sellers that have a good record of successfully completing sales. If you’re unable to complete a sale, it may impact your Seller fees.