How to become a Wayfair supplier: requirements, CastleGate and integration

Wayfair does not work like Amazon's or Walmart's marketplaces. You do not list an offer and set a price. You become a supplier: you set the cost Wayfair pays you, and Wayfair prices the item and sends purchase orders. The daily work sits in feeds and order messages that must run on time.

Is Wayfair a marketplace or a supplier program?

It is a supplier program. You set a base cost for each product, the wholesale price you are paid. Wayfair sets the retail price and pays for shipping to the customer on its own small parcel (FedEx), LTL or White Glove accounts. You book daily small-parcel pickups and pay their fees; Wayfair arranges pickup for large-parcel orders registered in Partner Home.

Wayfair prices with a dynamic system. It names your base cost as a major input, along with shipping cost, inventory positioning and incident rates. Your levers are base cost, stock availability, stock location and how few orders go wrong.

You are paid Net 60 from the invoice date, or within 30 days through Quick Pay for a 2% fee. Wayfair reported 21.7 million active customers as of June 30, 2026, and its seller site calls it a leading retailer in the U.S., Canada and the UK.

What do you need to become a Wayfair supplier?

Wayfair's onboarding checklist asks for business details and IDs, a warehouse or 3PL in the selling region that packs and labels to industry standards, a payout account in that market's currency, tax registrations where required, a certificate of insurance, and a returns setup. Each product needs at least three clear images (1000x1000 px or bigger) and specs from MPN and supplier part number to carton dimensions and wholesale cost.

Wayfair's Beginner's Guide also requires compliance with its Supplier Code of Conduct and excludes some categories, including medical devices, power tools and exercise machines. Wayfair verifies your business information while you complete setup, and products become purchasable once you add them and upload positive inventory.

Should you connect through Partner Home, EDI or the API?

Partner Home is the web portal for handling orders, packing slips, labels and inventory by hand. In our experience it fits low order volume.

EDI trades data on a schedule rather than live. Wayfair pitches it as the less tech-intensive automated route for suppliers not ready for the API.

The API runs in real time on GraphQL and covers catalog, inventory, purchase orders, labels, cancellations, CastleGate and advertising. It is open to suppliers already selling through Partner Home, and sandbox testing is required before Wayfair issues production keys. Once live, Wayfair tells you to switch off old EDI or Partner Home feeds so orders are not processed twice.

Wayfair's API rules for the drop-ship cycle:

Step	What Wayfair asks for
Inventory, full feed	A complete snapshot of active products, at least once every 24 hours
Inventory, changes	Differential updates as often as you allocate stock, ideally every 30 minutes
New orders	Query open purchase orders every 30 minutes, up to 25 per call
Accept	Accept each line as soon as possible; part number and unit price must match the PO
Register and label	Required if you use Wayfair labels or large parcel pickups
Ship notice (ASN)	Sent when the shipment leaves, with carrier code and tracking; ship date no more than 10 days back or 1 day ahead
Backorders	Set by hand on the Partner Home orders page; not available through the API

Wayfair recommends per-warehouse inventory rather than one total. A feed sent before recent orders are allocated can show units already sold, so Wayfair advises decrementing stock only after you accept a PO, and querying and accepting orders more often than you sync inventory.

Should you use CastleGate or drop-ship?

CastleGate is optional and has two parts. Forwarding handles ocean freight, drayage, consolidation, insurance and customs clearance. Fulfillment stores your stock in Wayfair's network and picks, packs and ships it. Wayfair says its CastleGate network has 15 fulfillment centers in three countries and can deliver to 97% of Wayfair customers in as little as two days. Its Multichannel Fulfillment program (US, Canada, UK) can also ship orders from your other channels.

Drop-ship keeps one inventory pool in your own warehouse. Wayfair names inventory positioning as a pricing input, and CastleGate is its way to place stock closer to shoppers. The cost is a split pool: another location to replenish, more fees, and another report to reconcile.

How does Growth OS run Wayfair next to your other channels?

We deploy Ecomsellertool Growth OS on your own accounts and add Wayfair as one more channel on the same catalog, stock pool and order flow. The Wayfair-specific parts:

1. Base cost per SKU from landed cost and a target contribution margin, because Wayfair owns the retail price.
2. Inventory feeds per warehouse, sent after allocation so sold units do not show.
3. Orders routed to the right warehouse once accepted, with backorders flagged for Partner Home because the API cannot set them.
4. CastleGate replenishment planned next to FBA and your 3PL, with each warehouse's counts reconciled against your records.
5. Cash timing per SKU per channel, with Net 60 or Quick Pay terms in the margin report.

These API flows are tested in Wayfair's required sandbox before going live. Wayfair is one of the 20+ marketplaces we have shipped integrations for, and the catalog and order layer draws on what we built for Ecom Global, designed for 100M+ products across 20+ marketplaces and 13+ carriers. Where your operation needs more, we add custom software and AI agents. Custom work is yours, and the Growth OS base is licensed to you.

Where should you start?

If you are applying, prepare the catalog specs and order plan first: Wayfair says most suppliers finish onboarding in a few days when their details are ready, and it may take two to three weeks otherwise. If you already supply Wayfair, the paid Deep Diagnostic in our Ops Gap Diagnostic reviews your Wayfair feeds, orders and stock alongside your other channels to show where they leak revenue; the free Quick Scan covers your top three Amazon gaps. The base system is Growth OS.