IOS8 Continuity calling, o2, UK - How to turn it off

Question

Hi All,
I've seen the suggestions about switching off cellular calls on an iPad to stop it ringing under continuity, however, my problem is different.  In my home there are 4 iPhones and 2 iPads.  I have a works and personal mobile, one for the wife and one for my son.  All used to be setup under my apple ID so all rang at the same time when we are all at home when we updated to ios8.  I've set up new apple ID's on the works phone and my wife's phone now to stop the problem, but it does cause another issue with App updates, you get the following message when trying to update on either of these (both are included fully on the family sharing):
The apps are all still on the original iPhone, and as it happens, are all free apps.
Using different apple ID's does solve the continuity calling problem, but I've also seen many users advise to turn off cellular calling in FaceTime.  This seems to be fine for an iPad, but what about 4 iPhones?  The option screen to turn off cellular calling in FaceTime setting is simply not there on an iPhone.
Probably a daft question, but would a simple button to "enable continuity calling" not be a sensible idea?  I mean it is a great feature if it suits your home or office, but if it doesn't, i'd like to be able to keep things simple under one apple ID over multiple devices and just switch off continuity on the devices I didn't want to use it on.
Am I missing a setting or process to fix this matter another way?  Any help appreciated.

Answer 1

There is one as you already know. Turn off Settings > Facetime > iPhone Cellular Calls
But since the whole point of continuity calling is to be able to access your cellular calls on non-iPhone devices when the iPhone is elsewhere, having that option for an iPhone makes no sense. Using the same iCloud account for multiple people is messy at best. This is why Apple give you the ability to set up individual Apple IDs for iCloud services and a common Apple ID for purchases. Family Sharing now allows a more seamless way to do that without configuring multiple Apple IDs on each device.