If you wish to use book shipments using the ParcelLetter service with DPD Netherlands, you will need to speak to your DPD.nl account manager to ask for this service to be enabled for your account.
If you try to book a shipment using the ParcelLetter service and it has not been enabled on your DPD.nl account, you will receive the following error: (ROUTING_14) Service code error
For any other questions, please get in contact with the Shiptheory support team.