What happens if I cancel a label after it was scanned and "Accepted at a USPS sorting facility"

If you cancel a label after the shipment has entered the mail stream, it will have no affect on the delivery of your shipment. The act of cancelling a label with ShippingEasy prompts Stamps to process a refund. However, after a label has been scanned and accepted by USPS, it is no longer eligible for a refund.