Among other issues, Apple has longstanding problems with their customer identity infrastructure and how it intersects with their device registration, DRM rules, and messaging systems. Under iOS 8, for example, there appear to be 4-5 different authentication channels for Apple products even when a user has only one AppleID.
Which is why, in the course of moving the kid’s iPhones around, I made a list of the steps I take when deactivating an old iPhone (for sale, disposal, or migration to the backup stack):
- log out of FaceTime (remove credentials)
- deregister iMessage: iMessage turn off, FaceTime logout and turn off
- remove iTunes Store AppleID account information (which can differ from iCloud AppleID)
- from Settings:Mail,Contacts, Calendars:iCloud:Advanced:Share My Location: From: (Your device) remove unwanted devices
- log out of iCloud/Find Phone
- log out of FindFriends
- if you can figure out which apps or content apps use DRM to limit installs, then sign out from those (Example, Inkling books.) Good luck.
- wipe phone
- power off
- Manage your associated devices in iTunes
- Remove device from Apple support/Apple ID device profile? (this is an ugly business)
- In Find iPhone on another device you can remove the device from the list. You’ll need iCloud credentials associated with each device. I believe this updates Apple’s record for device owner.
Note that you can change the iTunes Store Apple ID associated with an iPhone only every 90 days.
Did I miss anything?
By the way, even after doing all this, I found lots of old devices when I use iOS 8 FindPhone...
While browsing Google Account Security I found this ..
Google keeps track of devices (unclear how it identifies a device) in addition to credentials. If it gets valid logins from an unknown device it sends out a warning email.
So if you want to be very careful when you retire an old iPhone, you should review the Google Account Security Device activity & notifications page for every Google account you use and remove the old device.
I haven’t bothered to do this methodically, but it’s a reminder of how hard it is to throughly remove all connections between one’s identity and one’s devices.