To send a letter or package it is important that you have paid sufficient postage. It is the sender who is responsible for the shipment's correct postage.
If a consignment is missing or has too little postage, the sender must pay the missing postage and an additional fee. If we do not know the sender, the recipient must pay.
To find the right postage, see prices for packages and letters.
If you have received an invoice for missing postage, you can log in to view the picture of the shipment. You will find login details on the received invoice.