You can join Costco Wholesale by completing an online application at Costco.com. Alternatively, you can obtain a membership application at the membership counter of any Costco location or by calling 1-800-774-2678. Costco issues membership cards upon receipt of the completed application and applicable fees.
Costco mails membership cards within seven to 10 days of receipt of an online or mailed application. Individuals who apply for membership in person at a Costco membership counter receive their membership cards immediately. Those who use a paper application and do not submit it in person can mail the completed application to Costco Membership, P.O. Box 34783, Seattle, WA 98124-1783.