Hello, 16v827. Thanks for reaching out to us on the forums. I apologize to hear you are having issues with trying to set up the 2nd number. You should be able to set up to 4 different numbers. You would need to set up different user ids on your account to assign the numbers to and this could be why it's greyed out. For help with adding users to your account please see the following link: https://www.xfinity.com/support/articles/adding-new-user-names-or-email-addresses
If you still run into issues please send me a PM with your first and last name so I may further assist you
To send a private message, please click my name "ComcastMichael" then select "Send a Message" on the right side.
Hello, 16v827. I have not heard back from you. I hope the issue was resolved. If you still need assistance, please feel free to start a new thread.