Does Costco have a supplier application website?

No public online application. Costco's Vendor Inquiries page says non-food and sundry prospects contact the Issaquah corporate office (mail to PO Box 34331, Seattle, WA 98124) and food and sundry prospects contact their regional office; U.S. small and diverse businesses can use the Supplier Inclusion form. Buyers decide what goes in.

Will I get a 1099-K for sales to Costco?

No. Costco is a buyer paying invoices, not a payment platform, so it issues no 1099-K, and the IRS instructions list payments for merchandise as an exception for Forms 1099-MISC and 1099-NEC. Costco will still ask for a W-9 or W-8BEN-E, and all of the income must be reported.

Do I charge sales tax on sales to Costco?

Generally no. Costco is the retailer and collects from members; your sale is for resale, exempt with Costco's resale or exemption certificate kept for each delivery state. States where you have a warehouse or office may still require registration and returns reporting exempt sales.

How do I book discounts and allowances Costco deducts from payments?

Book revenue gross, then record early payment discounts, promotional allowances, rebates, shortage and damage deductions and returns separately, most as reductions of revenue. Reconcile each payment to the remittance advice and dispute errors within the agreement's deadline.

How to Become a Costco Supplier: Process and Tax Setup

Costco has no public supplier application system and is not an open marketplace. Its website only lists contact routes: non-food and sundry prospects contact the Issaquah corporate office, food and sundry prospects contact a regional office, and U.S. small businesses can use the Supplier Inclusion form; category buyers decide what goes in. For tax, you are a wholesale supplier: Costco collects sales tax from members, you sell for resale, and no 1099-K comes your way. Settle the contracting entity, the W-9 or W-8BEN-E, how goods will be imported and insurance before you talk to a buyer.

What is the process for becoming a Costco supplier?

As of November 2026, Costco's Vendor Inquiries page has no online application. It routes prospects by category. Non-food and sundry items go to the corporate office, with a mailing address of PO Box 34331, Seattle, WA 98124. Food and sundry items go to the regional office. The U.S. has eight: Northwest (Issaquah), Northern California (Livermore), Los Angeles (Garden Grove), San Diego, Texas (Plano), Midwest (Addison, Illinois), Northeast (Sterling, Virginia) and Southeast (Duluth, Georgia).

U.S. small and diverse businesses can also fill in Costco's Supplier Inclusion intake form. Its first question is whether the company is owned and operated in the U.S.; Costco says it can't process requests that don't meet its criteria, and submitting doesn't guarantee a business relationship.

Once a buyer is interested, the usual sequence is samples; a quote in the buyer's format, with the price terms (FOB, DDP and so on) spelled out; Costco's supplier agreement; the Supplier Code of Conduct, including disclosure of every production facility; item setup (UPC/GTIN, packaging and pallet specs, EDI); and a first test order. Exact steps and timing come from the buyer and the supplier materials; Costco doesn't publish them.

What does Costco look for, and why is it hard to get in?

Costco's Form 10-K for fiscal 2026 (year ended August 30, 2026) is direct about it. Each warehouse carries fewer than 4,000 active SKUs, with 9,000 to 11,000 online on average. Costco seeks to limit most items to fast-selling models, sizes and colors, and many consumables are sold only in cases, cartons or multipacks. It runs 939 warehouses worldwide, 647 of them in the U.S. and Puerto Rico.

Few items means a product that gets in sells in large volume, and also that competition is intense and an item that underperforms can be replaced. Margins are thin: in fiscal 2026, net sales less merchandise costs came to about 11% of net sales, gasoline included. The 10-K also says that when costs rise, Costco works with suppliers to share in absorbing them. Your quote needs duties, freight, deductions and returns built in.

What should the company and tax side look like before you sign?

First, pick the contracting entity. The entity that signs, invoices, gets paid, imports and holds the insurance should be the same one. A U.S. brand usually uses its existing LLC or corporation; a foreign factory can sign through its home company or form a U.S. subsidiary. Changing entities after signing means setting up again and can delay orders.

Second, give the right tax form. Costco is a buyer paying invoices, not a payment platform, so it issues no 1099-K, and the IRS instructions for Forms 1099-MISC and 1099-NEC list payments for merchandise as an exception, so the payments aren't reported on a 1099 either. Costco will still ask for a tax form: a W-9 from a U.S. company, with a name and EIN matching IRS records exactly, or a W-8BEN-E from a foreign company. A single-member LLC owned by one foreign person is disregarded for tax, and under the W-9 instructions the foreign owner gives a W-8 rather than a W-9 under the LLC's EIN. That structure deserves a hard look before large wholesale contracts.

Third, manage resale certificates. Your sale to Costco is a sale for resale, exempt with Costco's resale or exemption certificate. Keep certificates by delivery state. In states where you have a warehouse or office, many states still expect you to register and file returns reporting the exempt sales. Deliveries into Washington also raise Washington's B&O tax, which applies to wholesaling.

Fourth, catch up past filings. A U.S. corporation 25% or more foreign-owned, or a foreign-owned single-member LLC, files Form 5472 every year, with a $25,000 starting penalty per missed form. When a large customer reviews you, your company's standing and filing history should hold up.

Fifth, take insurance and the contract to an attorney. Costco's supplier agreement generally requires product liability insurance and indemnities; limits aren't published and the agreement governs. Contract terms, product liability and product compliance are for an attorney and testing labs.

How do you book Costco's deductions and rebates?

Costco's 10-K accounting policy says it receives funds from vendors for discounts and a variety of other programs ("vendor consideration"), which reduce its merchandise costs. On the supplier's side, payments often arrive as invoice amount less deductions: early payment discounts, vendor-funded promotions, volume rebates, markdown allowances, shortage and damage deductions, and returns.

Book revenue gross, then record each type of deduction separately, most as reductions of revenue. Reconcile each payment to the remittance advice, and dispute wrong deductions within the agreement's deadline. With no 1099-K summarizing anything, complete records are on you.

An example

Example (hypothetical numbers, to show the method): a North Carolina brand operating as an S corporation supplies Costco with 40,000 storage bins a year at $15 each, $600,000 invoiced. Remittances deduct a 2% early payment discount of $12,000, promotional allowances of $18,000 and $3,000 for damage and shortages. The books show $600,000 of revenue and $33,000 of revenue reductions, $567,000 net, before cost of goods and expenses. Booking only the cash received would hide the deductions, and any taken in error would never be recovered.

Learn more

For Costco Next's status, Kirkland Signature manufacturing, FOB versus DDP, U.S. tax for foreign factories, an entity-choice table and a channel comparison, see the guide to becoming a Costco supplier. To check which entity should sign and how to fill in your tax forms, book a free 15-minute call or add WeChat YCLUSA.