EDI 856 Advance Ship Notice: the document that decides whether your 3PL gets charged back

An EDI 856 is the advance ship notice. It goes from the shipper to the retailer once the shipment is packed and before the truck arrives, and it lists the shipment's structure: which orders are on it, which pallets, which cartons in each pallet, which items and quantities in each carton, plus carrier, tracking and expected delivery date. The retailer's receiving system uses it to plan the dock and to check the delivery in by scanning labels rather than counting.

The 856 matters more than any other document because it is where physical accuracy and data accuracy have to match. The serial shipping container code (SSCC) printed on each pallet or carton label must appear in the ASN's MAN segment, the quantities must add up through the hierarchy, and the ASN must arrive before the truck. Retailers publish a compliance guide with the exact rules and fine every miss: late ASN, missing ASN, ASN that does not match what was received, label that does not scan.

This is the 3PL's document even when the brand's EDI provider technically transmits it. The warehouse builds the pallets, generates the SSCCs, prints the labels and knows the carton contents. The cleanest setups have the WMS create the 856 data at pack confirmation and send it to the EDI provider automatically; the worst have someone re-keying pallet counts into a web form after the truck has left.