Walmart EDI requirements, without the 60-page guide

The document set

For a typical supplier shipping to Walmart distribution centers, the core transactions are:

• 850 purchase order — arrives from Walmart, usually several times a day.
• 855 PO acknowledgment — confirms quantities and any changes; expected quickly and often within a day.
• 856 advance ship notice — the one that matters most, because it drives receipt and payment.
• 810 invoice — must reconcile to the PO and to what was actually shipped.
• 997 functional acknowledgment — tells Walmart you received their file; it is not a correctness check.
• 846 / 852 — inventory advice and product activity, required for some categories and vendor models.

SSCC-18 and the GS1-128 label

Walmart's ASN is only half the requirement. The other half is the physical label: an SSCC-18 serial number encoded as a GS1-128 barcode on each pallet and carton, matching the 856 exactly.

Practical consequences: your case pack and pallet configuration must exist as real data, your printer and label stock must be tested before the first shipment, and the serial numbers must be unique and sequential — not reused from a previous order.

• Test one real label on a real printer before the go-live, not a PDF preview.
• Keep SSCC numbers in a sequence you can prove; scammers and auditors both ask.
• If a pallet is split at the dock, the ASN is already wrong. Ship what you said.

Transport and testing

Walmart suppliers connect by AS2 or through a VAN, and must pass a testing cycle before production orders flow. The testing queue is the schedule risk: it starts when Walmart has capacity, not when you are ready.

Item setup matters as much as EDI. GTINs, case packs, dimensions and weights have to be correct in Walmart's item file before an 850 can be fulfilled cleanly.

• Start transport paperwork (AS2 certificates or VAN mailbox) on day one.
• Request the test IDs early; the wait is often longer than the mapping.
• Send test documents with a deliberately awkward item, not your cleanest one.

Where Walmart chargebacks come from

Walmart's supplier agreements include chargebacks — often called fines — for compliance failures. The EDI-adjacent ones are predictable:

• ASN mismatch — quantity, pallet count or DC on the 856 does not match the shipment.
• Label failure — missing, unreadable or duplicate SSCC-18; label not on every carton required.
• Late or missing ASN — the notice must precede receipt, not follow it.
• Invoice mismatch — 810 total or line quantities disagree with the PO and receipt.
• Acknowledgment timing — 855 not returned inside the window in the supplier agreement.

A realistic timeline

For a supplier with item data ready and a clean catalog: transport in days, mapping in days, testing in one to three weeks depending on queue, first live order after that. Suppliers who start with missing item data lose two to four weeks before any of it begins.

• Week 1 — transport, item data, testing request.
• Week 2 — map and test 850/855/856, print real labels.
• Week 3 — 810, reconciliation, re-test after rejections.
• Week 4 — go live with monitoring.

Questions

Keep reading

• What an EDI letter means, and the seven-day plan
• The Walmart 856, segment by segment
• The Target ASN: what breaks first
• The Kroger ASN is a pallet document
• SSCC-18 labels and why they fail
• What EDI costs, with published prices
• Chargebacks: the five causes
• SPS Commerce alternative for small suppliers