One person, one Apple ID. That’s a simple rule that leads to harmony in the Apple ecosystem. All too often I see people breaking this rule. They will share an Apple ID with another person, or have multiple IDs themselves.
That leads to trouble. A purchase made on an Apple ID, whether it is a song, an app, or a service, is tied forever to that Apple ID. In addition, messaging from one person to the other, via email, iMessage or FaceTime, is tied to that Apple ID to.
So you get situations where two people share an Apple ID so they can share purchases. But then they start using iMessage and now find that they see each other’s messages and it gets confusing if they try to send messages to each other. Apple’s servers see all devices sharing the same Apple ID as belonging to the same person. So you may have an iPhone and your spouse may have an iPad, and you may be in separate places, but when someone sends you a message, they are sending it to both devices. Plus, any other iCloud services will be shared. So you will share all of your calendars, notes, reminders, contacts, and so on.
I also see situations where someone has an Apple device and creates an Apple ID for it. They purchase some items and maybe set up messaging. Then they get a new device and without thinking about it they set up a second Apple ID for that device. Now they have two Apple IDs and are missing out on sharing apps between them, or using iCloud services, or even seeing their messages on the device they are holding because the message was sent to the other person. Apple sees these devices as owned by two separate people.
Stop the Problem Before It Happens
If my advice here is able to catch you before you make the mistake of setting up a second Apple ID, or before you decide to share an Apple ID with a spouse or other family member, then now you know. Don’t do it. Follow the rule of one person, one Apple ID.
Use the same Apple ID on all of your devices: iPhone, iPad, Macs, multiple Macs. You can get your messages on all of your devices, share apps in the App Stores, and share files across iCloud.
If you don’t want to do one or more of these things, they can all be disabled on a device-by-device basis. So there’s no excuse for creating a second Apple ID for a device just because you don’t want to get messages there. Use the same Apple ID and turn off messages on that device.
Fix the Problem Afterwards
But what if it is too late? What if you have been sharing an Apple ID with someone for years? What if your wanted your child to use your Apple ID so you could monitor them? Or you shared with your spouse so you could buy apps and music and both use them?
Well, this is gonna hurt. But there is no other way than to simply create a new account for that other person and start fresh. The more you wait, the more it will hurt. But it has to be done.
However, it doesn’t mean that they have to lose all of their apps, music and other things. Apple has a solution for that. You can use Family Sharing to share purchases between accounts. So when you create that second account, start using Family Sharing to let the other person continue to access those apps. You can also share calendars and other iCloud items between each other.
But expect hiccups. It wasn’t long ago that Family Sharing didn’t exist and that second account would have no way to access their apps and other purchases other than simply buying their stuff again. Things are much better now, but I wouldn’t expect them to be perfect.