Wayfair EDI requirements for dropship suppliers

What Wayfair publishes, and where

Wayfair's EDI documentation is on its developer portal, developer.wayfair.io, and is readable without an account. It covers three programs: Dropship, where the supplier ships each customer order from its own warehouse; CastleGate, where the supplier's stock sits in Wayfair's fulfillment network; and Multichannel, where orders from the supplier's other channels are fulfilled from CastleGate. Each document has a data map with segments, element limits and notes. Everything below comes from those pages, read on 3 October 2026, and concerns Dropship unless stated otherwise. Wayfair is one of the trading partners we build an EDI integration for.

Wayfair's setup runs in four steps: review the specifications and build the maps, request the integration in Partner Home with the connection profile and EDI qualifiers, exchange test documents once Wayfair has provisioned the request, and move to production.

Connections: a VAN, AS2 over HTTPS with certificates uploaded for both development and production, or a Wayfair-hosted SFTP endpoint that Wayfair provides free of charge. For Dropship, Wayfair also accepts a CSV flat file for the 850, 856, 810 and 846, and it runs GraphQL APIs for the same flows.

The dropship documents

An 850 for one dropship line, built to Wayfair's map with our own example values:

ISA*00*          *00*          *01*112084681      *ZZ*NORTHFIELD     *261003*0815*U*00401*000000731*0*P*>~
GS*PO*112084681*NORTHFIELD*20261003*0815*731*X*004010~
ST*850*0001~
BEG*00*DS*CS512304871**20261003~
REF*VR*41822*43215~
REF*2P*Wayfair~
DTM*038*20261006~
TD5**2*ABCD*ZZ*GROUND~
N1*ST*J SMITH*54*41822~
N1*LW*J SMITH~
PO1*1*2*EA*12.50*WH*VN*10482~
CTT*1~
AMT*GV*25.00~
SE*12*0001~
GE*1*731~
IEA*1*000000731~

REF*VR carries the supplier ID with the warehouse ZIP code, and Wayfair's note says this ID "must be used on all order documents". DTM*038 is the ship-no-later date. The N1*ST loop is where the parcel goes; the N1*LW loop is the name that goes on the packing slip. REF*2P names the Wayfair brand the order was placed on. The address and PER contact segments are left out of this sample, and SE01 counts the 12 segments that remain from ST to SE.

Cancellations: the 860 and the 24-hour 865

Wayfair uses the 860 for one thing in dropship: partial and full cancellations. POC02 QD (quantity decrease) asks the supplier to confirm or reject, and needs an 865 back. DI (delete item) needs no answer, because the change was already confirmed or fell inside the guaranteed cancellation period. POC04 gives the new remaining quantity, 0 for a full cancellation.

The 865 answers with BCA01 06 and BCA02 AT to accept the cancellation, or 44 and RJ to reject it, for example because the parcel is already packed. It is due within 24 business hours; without it Wayfair cancels the order. An integration that holds an 860 until someone looks at it loses orders this way. The 860 has to reach the warehouse at once, because only the warehouse knows whether the parcel can still be stopped.

The ship notice and the invoice

Wayfair's 856 map uses BSN05 0001 (shipment, order, pack, item) or 0002 (shipment, order, item, pack), and the notes add the rules that cause rejections:

• One purchase order per 856; several 856s may go in one batch.
• LIN03 must equal PO107 from the 850, the vendor part number exactly as Wayfair sent it.
• The SCAC and ship speed in TD5 must match the 850.
• Small parcel: tracking in REF*2I for one item, in MAN*CP per package for several. LTL and white glove: the PO number may stand in REF02 and the GS1-128 package ID goes in MAN*GM.
• TD107, the weight, is not decimal implied.

The 810 is optional in dropship, but Wayfair says invoices that do not match the ship notice and PO "may be rejected or delayed in payment processing", and that an invoice cannot be processed without the full cost in the required segments. Each IT1 must match quantity, unit price and part number from the 850. Charges and allowances in SAC use a fixed code list, such as D240 freight and H750 tax.

The decimals are where a correct invoice turns into a wrong one. In Wayfair's map IT104 (unit price) is not decimal implied, while TDS01 (invoice total) and SAC05 (charge amount) are. For the order above with 6.95 freight:

An integration that writes TDS*31.95 sends a total that Wayfair reads with two implied decimals, and one that writes IT1 with 1250 invoices a unit price of 1,250.00.

Inventory feeds

The 846 reports, per item and warehouse, the quantity available to ship (QTY*33), a discontinued flag in LIN05, and optionally the quantity on order with its availability date (SCH, qualifier 169). The warehouse is identified by the ID Wayfair issues at onboarding in LIN07. Wayfair expects every active item for every active warehouse, recommends quantities per warehouse over one total, and prefers the SCH line when the quantity is 0. BIA01 is 00 for a full file and 04 for a difference file.

One 846 holds at most 10,000 LIN loops. A supplier with 6,500 items in 3 warehouses reports 6,500 × 3 = 19,500 item-warehouse lines, which is two documents: 10,000 and 9,500. Because Wayfair expects every active item, an item that runs out is sent with quantity 0 and, where known, a back-in-stock date in SCH, not left out of the file. Which stock counts explains the choice of quantity.

Handling Wayfair orders on the ERP side

Each Wayfair 850 becomes a sales order for one consumer, with the supplier ID, the PO number, the vendor part number exactly as sent, the carrier and ship speed, the ship-no-later date and the packing-slip name. The warehouse has to know about an 860 while the parcel can still be stopped, the 856 is built from the parcel once it has left, and the 810 from what shipped at the 850's cost.

We build that part to Wayfair's maps and your systems: 860s routed to the warehouse at once and 865s answered within the deadline, the 856 checked for LIN03, TD5 and tracking before sending, implied decimals written per element, and the 846 split at 10,000 lines. A document that fails a check is held with the reason in the dashboard. Tell us how you supply Wayfair.