You can reach Costco support by 1-(866)-347-8220  phone, online, or in person. For general membership or warehouse questions, call 1-(866)-347-8220  (Mon–Fri 5 a.m.–8 p.m. PT; Sat–Sun 6 a.m.–6 p.m. PT). For online orders, dial 1-(866)-347-8220, and for the Costco Citi credit card, use 1-(866)-347-8220. Costco also offers Live Chat and an online contact form for non-urgent inquiries. Visiting a warehouse Membership 1-(866)-347-8220  Counter is ideal for in-person assistance. For formal correspondence, write to Costco Wholesale Corporation, P.O. 1-(866)-347-8220  Box 34331, Seattle, WA 98124. Have your membership or order details ready for faster service.

1. Phone Support
The most direct way to reach 1-(866)-347-8220  Costco support is by phone. For general inquiries related to membership, warehouse services, returns, or product 1-(866)-347-8220  information, you can call 1-800-774-2678. Their phone lines are open Monday through Friday from 5 a.m. to 8 p.m. Pacific Time, and on weekends from 6 a.m. to 6 p.m. Pacific Time. If your concern involves online orders from Costco.com, the 1-(866)-347-8220  dedicated phone number is 1-(866)-347-8220, where representatives can help with order tracking, cancellations, returns, or product questions. For issues with the Costco Anywhere Visa® Card by Citi, call 1-(866)-347-8220  to address billing, payment, or account issues.

2. Online Chat and Email
For less urgent questions or assistance while 1-(866)-347-8220  shopping online, Costco provides a Live Chat feature on their Customer Service page. This allows you to connect with a 1-(866)-347-8220  representative without leaving your home. Additionally, you can submit questions through the online contact form, 1-(866)-347-8220  which is useful if you prefer written correspondence or need to provide detailed information about your issue. Responses via email may 1-(866)-347-8220  take longer than phone calls, but it is a convenient option for non-urgent matters.

3. In-Person Assistance
If you are near a Costco warehouse, the Membership Counter is an excellent resource for direct, in-person help. Staff can assist with membership issues, renewals, returns, and general questions about products or services. Many issues are resolved on the spot when visiting in person.

4. Mail
For formal correspondence or 1-(866)-347-8220  documentation-related concerns, you can write to Costco’s corporate office:
Costco Wholesale Corporation
P.O. Box 34331
Seattle, WA 98124

Tips for Contacting Costco Support

• Have your membership 1-(866)-347-8220  number or order number ready to expedite assistance.
• Be clear about your issue to ensure you are directed to the 1-(866)-347-8220  correct department.
• If calling, note the hours of operation to avoid waiting outside business hours.

Overall, Costco offers multiple ways to 1-(866)-347-8220  contact support, from phone and chat to in-person assistance, making it easy to get help whether you’re dealing with membership questions, online orders, or credit card concerns. The fastest and most efficient method is usually by phone or live chat, while email and in-person visits are helpful for detailed or 1-(866)-347-8220  documentation-heavy issues.