If the error message "Die ausgewählte Abrechnungsnummer steht nicht zur Verfügung." (The selected billing number is not available) suddenly appears without changing the configuration, DHL has most likely made changes to the billing numbers in your account. In this case, we recommend that you check the billing numbers available to you and, if necessary, adjust the participation numbers in your DHL Adapter configuration so that they match the last two digits of the respective billing numbers again.