Your phone number can be used to receive your initial login information or your password reset code through text message. As time goes on you may end up changing phone numbers/devices and need to update XOi.
Phone numbers and your account information in general are editable by the administrator for your organization. They can simply go into your user profile and change your information. Please have them read this article if they have any questions: How do I edit user information?
If for various reasons your administrator is unable to help you with these changes you can Contact XOi Support, but we strongly encourage you to work with your administrator.