For air and/ or ocean back-to-back shipments does a freight forwarder need to transmit eHBL secondary data or is the ACI S10 allowed?

For air and/ or ocean back-to-back shipments does a freight forwarder need to transmit eHBL secondary data or is the ACI S10 allowed?

As of November 1, 2020, you may transmit eHBL data for air or ocean back-to-back shipments, by January 4, 2021 you should transmit eHBL data and by June 4, 2021 you must transmit eHBL data, within the modal timeframes.