Sharing AppleID
Ive always used the same ID between my home cell, my cell and my son’s cell. I always had option to choose which number on separate devices to send and receive messages. Why can’t I do that any longer the option is gone?
Question marked as
The option should still be there and is for me under Settings > Messages > Accounts.
With that said, the Apple ID should be separate for each person. It is OK for you to share the Apple ID among you own devices, but your son should have his own Apple ID. You would still be able to share subscriptions and manage your son's device using Family Sharing.