As long as you are the Primary Member or Account Manager, you may view and update your membership account information online at Costco.com. Here's what you do:
Sign in / Register and head to "My Account." You can update your information in the "Account Details" section. Keep in mind, your membership will need to be verified before you can make any membership changes online. Check out the types of changes you can make online here.
If you are unable to verify your membership online, please visit the membership counter at your nearest Costco location with a photo ID to verify your membership, or contact us.