As with other carriers, you can cancel USPS postage by going to the track tab and voiding the shipment.
When you cancel/void postage that you purchased through our service it takes 3-4 weeks to get the money back from the US Post office. Once we receive the funds from USPS, we will deposit it back as a credit to your account.
You can check for your credit here: https://shipleap.freshdesk.com/a/solutions/articles/48001221452
Keep in mind, that there is a transaction fee with every USPS purchase. If you void the USPS label, we will issue a refund within the 3-4 week timeframe excluding fees. Be very careful with USPS batch purchases.