Are digital stamps invoiced straight after they have been created? Yes, digital stamps are invoiced straight after they have been created. Gerelateerde vragen How long is the digital stamp valid for? Why is there no discount offered on PostNL's letterbox parcel and digital postage stamp? 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?