Requirement remains voluntary for now The Canada Border Services Agency (CBSA) posted Customs message CN17-15, which outlines the revised implementation timelines. Customs Notice CN17-15 pushes eHBL implementation back by at least a year to May 24th, 2018. Until systems are robust and tested, ACI eHBL remains voluntary. As of August 14th, 2017, the option of allowing single shipments (back to back shipments) using the new ACI eHBL process to release goods from primary sufferance warehouses will be suspended. This information was summarized in Customs Notice 17-22. Prior to this date the CBSA is allowing freight forwarders to adjust and make any necessary processing changes, but we encourage freight forwarders to cease transmitting electronic house bills for back to back shipments destined to a primary warehouse as soon as possible.  After August 14th, 2017, freight forwarders are required to submit electronic legacy ACI S10 supplementary reports for air and marine back to back shipments clearing at a primary warehouse.  These shipments will be released on the primary cargo control number.  Legacy ACI S10 process requires freight forwarders to present paper house bills to the CBSA post arrival for validation for all consolidated house bills. The release request must quote the lowest level paper house bills destined to a CW sufferance warehouse.  SOURCE: Air Forwarders Association