I would like to change the phone number that is responsible for payment of the multi line payment. I have 4 lines in the multi line account. One of those numbers will soon change. I would like my phone number to be the payment number since the CC "Auto-Pay"account is my account anyway.
You need to have everyone drop off the current multiline autopay account first by going into each person's line and making that request. Then you set up the multiline account with your phone number along with the autopay info. Remind them to accept the multiline account invite to join. If the line wishing to change needs to stay on another month, have them join and then drop off from their account when they are ready to leave.