Costco EDI Integration: Wholesale and Costco.com Explained

Costco runs two vendor programs that do not even share a network, and assuming one program's rules apply to the other is where new vendors get hurt. Costco Wholesale vendors ship bulk freight to Costco depots over ANSI X12 EDI, under some of the strictest ship-notice enforcement in retail. Costco.com vendors drop-ship individual member orders through Rithum's OrderStream network, a different connection with different documents entirely. This guide covers both programs and where they split.

Jump to What You Need

If You Want To…	Jump To
Know which EDI documents Costco Wholesale requires	The Required Documents
Understand how Wholesale and Costco.com differ	Costco Wholesale vs Costco.com
See how purchase orders and acknowledgments flow	The 850, the 855, and the 24-Hour 997
Avoid the document behind most Costco chargebacks	The 856 ASN
Get paid without reconciliation holds	Invoicing and the Three-Way Match
Understand onboarding, testing, and connectivity	Getting Set Up for Costco EDI
See how the drop-ship rail works	Costco.com Through OrderStream
Run both programs without building EDI yourself	Costco EDI Through InfiPlex

What EDI Documents Does Costco Wholesale Require?

Costco Wholesale requires suppliers to trade over the ANSI X12 standard, connected directly or through a VAN, and to pass Costco's certification testing before live purchase orders flow. Four transaction sets carry the core order-to-cash cycle, with two more in regular rotation.

Document	Direction	What it does
850 Purchase Order	Costco to you	The order itself: items, quantities, pricing, and the depot or warehouse ship-to, referencing Costco item numbers.
855 PO Acknowledgment	You to Costco	Confirms whether you can fill the order as written, line by line, and signals ship-date feasibility.
856 Advance Ship Notice	You to Costco	Must arrive before the freight does: the full packing structure, pallet and carton detail, matched exactly to the physical GS1-128 labels.
810 Invoice	You to Costco	Bills for what actually shipped, reconciled against the 850 and the 856 in Costco's three-way match.
860 PO Change	Costco to you	Buyer-initiated changes to an open purchase order, which the downstream documents have to reflect.
997 Functional Acknowledgment	Both directions	Confirms each document arrived and parsed. Costco expects 997s back within 24 hours of a document landing in your mailbox.

One Costco-specific detail worth knowing before the first document flows: Costco assigns its own item numbers, separate from your UPCs and GTINs, and the documents reference them. Getting the item number mapping right is real setup work, not an afterthought, because a wrong item reference breaks reconciliation on everything downstream.

What Is the Difference Between Costco Wholesale and Costco.com EDI?

Where Target's two vendor programs at least share document numbers, Costco's two do not even share a network. Costco Wholesale is the warehouse club business: Costco buys your product and you ship it in bulk to depots and warehouses over X12 EDI. Costco.com is drop-ship: Costco sells your product online and you ship each order to the member through Rithum's OrderStream network, the platform Costco.com has run its supplier integration on since the CommerceHub era. Here is where the two diverge in practice.

	Costco Wholesale	Costco.com
Who you ship to	Costco depots and warehouses, bulk freight on pallets	The member, one parcel per order
The network	ANSI X12 EDI, direct or through a VAN	Rithum OrderStream (formerly CommerceHub), typically XML over sFTP
What arrives	Wholesale POs at pallet quantities, referencing Costco item numbers	Individual member orders with a name and address in the ship-to
The ship notice	856 with the full shipment hierarchy and GS1-128/SSCC carton labels, sent before the freight moves	Shipment confirmation through OrderStream with the parcel carrier and tracking number
Invoicing	810 per PO, reconciled three ways against the 850 and 856	Invoice documents flow through OrderStream
Inventory	Driven by Costco's buying and replenishment	Inventory feeds keep your items orderable on Costco.com
Compliance pressure	Receiving exceptions and per-shipment chargebacks, enforced at the dock	Fulfillment-timing expectations on every member order

A vendor can be in both programs at once, and plenty are. That means one document pipeline built for pallets and depots and another built for parcels and members, running side by side against the same inventory.

How Do the Costco 850, 855, and 997 Work?

The 850 opens every Wholesale order: items at pallet quantities, Costco item numbers, pricing, and the depot or warehouse ship-to. Costco runs both depot cross-dock and direct delivery models depending on the product category, and with more than 600 warehouse locations behind those depots, a single buying decision can put serious volume on one PO.

The 855 is your line-by-line answer: accept, accept with changes, or decline, with ship-date feasibility signaled per line. The same rule that applies at every major retailer applies harder here: an 855 that does not reflect what you will actually ship poisons the 856 and 810 behind it, because Costco reconciles all three.

The 997 deserves more respect at Costco than vendors usually give it. Costco expects functional acknowledgments back within 24 hours of a document hitting your mailbox, and a missing 997 reads as a missing document on their side. It is the cheapest possible document to get right, and one of the more embarrassing ones to get flagged for.

Why Does the Costco 856 ASN Carry the Strictest Rules?

The 856 is Costco's most enforced document, and the enforcement is physical: if the ASN has not arrived before the truck does, the delivery is effectively dead on arrival at receiving.

The file has to describe the freight completely and exactly. Costco requires the full shipment hierarchy, shipment, order, pack, and item levels, and an ASN submitted only at the pallet or carton level fails. Every carton carries a GS1-128 label whose SSCC serial must match the ASN data precisely, because Costco's high-throughput receiving lanes scan cartons against the file, and any mismatch between the label and the data surfaces immediately, commonly as a chargeback or a reship request at your expense. For perishable products, lot codes have to be embedded in the ASN from day one, not added by hand when someone remembers.

The depot model raises the stakes further. A cross-dock depot exists to move freight through fast, on the strength of the ASN data alone, so an error in the file does not stay at one dock, it follows the product toward every warehouse that shipment feeds.

How Does Costco Invoicing Work?

Costco pays Wholesale vendors against a three-way match: the 850 says what was ordered, the 856 says what shipped, and the 810 has to agree with both. Invoice what shipped, not what was ordered. A line that was shorted on the ASN has to be shorted on the invoice too, or the mismatch parks the whole 810 in reconciliation. The practical rule is the same one that holds at Target and Walmart: generate every invoice from the order and shipment records rather than by hand, because manual invoices are where PO numbers get mistyped and quantities drift.

Costco.com invoicing runs on the other rail entirely. There is no separate X12 810 to Costco for a member order; the order, shipment confirmation, and invoice documents all flow through OrderStream as part of the drop-ship exchange. Two programs, two invoicing patterns, one set of books to keep straight.

How Do You Get Set Up for Costco EDI?

There is no open online application to become a Costco supplier. The buyer relationship comes first, and the EDI mandate follows the vendor agreement, so the compliance clock starts the moment Costco decides to order from you.

For Wholesale, certification means proving the document loop on Costco's test cycle before live trading: the 850 in, the 855 and 856 and 810 back out, and the GS1-128 labels validated against the ASN data. Plan for two to four rounds of testing; the schedule is set by Costco's cycle, not yours. Connectivity is X12 over a direct connection or a VAN, and the item-number mapping between Costco's numbers and your SKUs has to be right before the first real PO, because that is what every document references.

For Costco.com, setup means an OrderStream account with Rithum and the document exchange configured through it. The network costs bill through your Rithum account, and Rithum's published structure runs on a fixed minimum plus a share of GMV, which is worth understanding before the volume grows. The math is laid out on our Cost of One Connection page.

Either way, plan the EDI timeline against your first PO date, not your contract date. Built traditionally, with an EDI provider, mapping work, and certification, retailer onboarding commonly runs into weeks. A managed connection with the Costco mappings already built compresses the vendor-side work to credentials, item setup, and the certification pass itself.

How Does Costco.com Drop-Ship Work Through OrderStream?

Costco.com has run its drop-ship supplier network on the platform now called Rithum OrderStream since the early CommerceHub years, and the mechanics are steady: member orders flow out to the vendor, the vendor ships one parcel per order directly to the member, the shipment confirmation with carrier and tracking flows back, and inventory feeds keep items orderable on the site. The exchange typically runs as XML over sFTP through your OrderStream account rather than raw X12 to Costco.

Operationally, that makes a Costco.com order look much more like a marketplace order than a wholesale PO: a name and address, a parcel label, a tracking number, and a fulfillment clock running against a member who is waiting. The discipline is different from the depot side, less about pallet hierarchies and more about never letting an order sit, and never letting the site sell stock you no longer have.

How Does InfiPlex Run Costco EDI?

InfiPlex connects both programs, and treats them as what they are: two rails into one order queue.

For Costco Wholesale, InfiPlex manages the EDI trading partner relationship, so there is no EDI software to license and no mapping to maintain. 850s arrive as ordinary orders alongside every other channel, with Costco's item numbers mapped to your SKUs. The 855 goes back in the window, the 856 is built from what actually shipped with the full pallet and carton hierarchy and GS1-128/SSCC data, the 810 is generated from the order and the shipment so the three-way match reconciles, and 997s are handled automatically in both directions.

For Costco.com, InfiPlex connects through your existing OrderStream account over the sFTP XML exchange, and member orders arrive as standard orders: route them to your own warehouse or a 3PL, and tracking and inventory flow back automatically. Details on the connection live on the InfiPlex Costco integration page. If your fulfillment runs through an ERP, the NetSuite integration keeps the ERP as the system of record while InfiPlex handles the retailer compliance around it, and if you want to see exactly what a retailer EDI order looks like running end to end on real screens, the Target Stores EDI product tour walks an 850 through fulfillment to the 856 and 810 with a shop log receipt for every document. Any other trading partner works the same way through the InfiPlex EDI integration.

Costco EDI Questions

Does Costco require EDI for all suppliers?
Yes for the Wholesale business. Costco Wholesale suppliers must trade the required X12 documents over a direct connection or a VAN and pass Costco's certification testing before live purchase orders flow. Costco.com vendors trade through Rithum OrderStream instead.

What EDI documents does Costco require?
The core set is the 850 purchase order in, and the 855 acknowledgment, 856 advance ship notice, and 810 invoice back out, with 997 functional acknowledgments expected within 24 hours in both directions and 860 purchase order changes arriving when a buyer amends an open PO.

What is the difference between Costco Wholesale EDI and Costco.com?
Different networks entirely. Wholesale is bulk freight to Costco depots over ANSI X12, with pallet-level ASNs and a three-way invoice match. Costco.com is drop-ship to the member through Rithum OrderStream, typically XML over sFTP, with parcel tracking and inventory feeds. A vendor can run both at once.

Why does the Costco 856 ASN matter so much?
It must arrive before the freight does, carry the full shipment, order, pack, and item hierarchy, and match the GS1-128/SSCC carton labels exactly, with lot codes embedded for perishables. Costco's receiving scans cartons against the file, so a mismatch surfaces at the dock as a chargeback or reship.

Does Costco use its own item numbers?
Yes. Costco assigns item numbers separate from your UPCs and GTINs, and the EDI documents reference them, so mapping Costco's numbers to your SKUs correctly is part of setup, not an afterthought.

How long does Costco EDI testing take?
Costco's certification cycle commonly runs several weeks across two to four rounds, covering the core documents and GS1-128 label validation. The schedule is Costco's; a managed connection with the mappings already built shortens the vendor-side work to credentials, item setup, and the certification pass.

Do I need a VAN to trade EDI with Costco?
Costco Wholesale supports direct connections as well as VANs, and running Costco through InfiPlex often reduces or eliminates VAN costs since InfiPlex manages the connection as part of the integration. Costco.com does not use a VAN at all; its network is OrderStream, billed through your Rithum account.

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