how to track a package with a tracking number usps involves entering the tracking number on the USPS website or using the USPS mobile app to check the status of a shipment. Once the package has been shipped, USPS updates the tracking information in real time, allowing the recipient to follow the package’s journey from departure to delivery. Tracking information typically includes updates on when the package is in transit, when it’s out for delivery, and when it has been delivered.