What if an item is insufficiently stamped?

If the sender is known and lives in Belgium, the sender may be asked to apply additional stamps and to pay certain additional costs paid by the postal service provider.

In case the sender is not known and the delivery address is situated in Belgium, the postal service provider may leave a message for the addressee requesting the latter to pay the postage still due and the additional costs.

Upon refusal or in case the item is not collected, the item is treated as undeliverable.