How long is the digital stamp valid for? Once the digital stamp has been downloaded, it is valid for five days. Gerelateerde vragen Why is there no discount offered on PostNL's letterbox parcel and digital postage stamp? Are digital stamps invoiced straight after they have been created? Why is there no Track & Trace code for the digital stamp? Does an unfranked label have a Track & Trace option? How do I add my own logo or text to a digital stamp?