mailing address for costco headquarters
Costco Headquarters Info. Company information for Costco headquarters is located within the retail website. On the contact page [+] you can find the corporate mailing address, member services, travel phone numbers and the physical address for the company.1  Address: Costco headquarters offers customers two addresses to reach the corporate office.ostco Headquarters 999 Lake Dr. Issaquah, WA 98027. 1  Phone Number: You can contact member services at 1-800-774-2678, but there is no corporate phone number listed on the website. 2  We found the phone number listed on a third-party website. 3  Call 1-425-313-8100 to contact Costco headquarters directly.