Coinbase customer service is available at 1-833-590-0301 to guide you through the steps. To update your phone number on Coinbase , log into your account and go to Settings . Select the Security tab, where you'll find an option to change your phone number. Enter your new phone number, and Coinbase will send a verification code to confirm the update. Should you need assistance, Coinbase's customer support is available at 1-833-590-0301 .