Costco does not have a marketplace. There is no seller portal, no listing fee, no referral percentage — because there are no third-party listings at all. Selling through Costco means one of two things: becoming a supplier Costco buys from, or joining Costco Next, the curated program most sellers have never heard of. Both are worth understanding, because Costco's 130-million-member base buys in a way no marketplace audience does.
Route one: become a Costco supplier
The classic path. Costco's buyers purchase your product wholesale — by the truckload, not the carton — and sell it in warehouses or on Costco.com. What buyers look for has not changed in decades: a genuinely good product, a price that survives Costco's famously thin markup, and proof you can supply volume without missing a shipment window.
The mechanics are pure retail: vendor application, buyer meetings, and once you are in, strict compliance — EDI documents for purchase orders, ship notices and invoices, pallet specs, delivery appointments. Miss the spec and the chargeback arrives before the truck gets home. It is demanding, and it is also the stickiest revenue in retail: Costco does not churn suppliers the way algorithms churn sellers.
Route two: Costco Next
Costco Next is the quiet one — a curated page on Costco.com where members click through to a supplier's own website and buy directly at member pricing. Costco holds no inventory; you ship every order, run customer service and take the returns. In exchange, your brand sits in front of Costco members with Costco's implicit endorsement, without fighting for warehouse shelf space.
Entry is by selection, like Target Plus: established brands with proven products and the fulfillment operation to ship direct-to-consumer at scale. If your operation cannot pick, pack and ship same-day at volume, Costco Next is not yet available to you — not because of paperwork, but physics.
What both routes have in common
Logistics is the audition. Wholesale means truckload shipments, routing guides, EDI and delivery windows; Costco Next means D2C fulfillment that never misses. Either way, Costco is betting its member trust on your back end.
That back end is our specialty: warehouse storage minutes from the Seattle and Tacoma ports, retail-compliant cross-docking and outbound FTL/LTL for wholesale programs, and pick and pack for direct orders. We already build Costco-compliant freight — the detail is on our Costco page.
