Q: My sister and I have been sharing the same Apple ID, and she has been receiving my iMessages. I think I’ve properly changed my Apple ID for iMessages in my iPhone, but is that sufficient or do I have to make changes in her settings? Will she stop receiving my messages?
A: Although switching to a different Apple ID on your iPhone should technically be enough to separate your iMessage traffic, this assumes that anybody communicating with you via iMessage is using an address that is assigned to your new Apple ID.
By default, when you change your iPhone over to a new Apple ID, the phone number on your iPhone should be assigned to the new Apple ID and removed from the old one.
You can confirm this by going into your Messages settings in the iOS Settings app and looking at the addresses that are listed in the “You can be reached by iMessage at” section; your iPhone’s number should appear here with a checkmark beside it, although it will be grayed out, as you can’t remove or de-select it.
But iMessages can also be sent to an e-mail address. So if you have any contacts that have used your previous Apple ID’s e-mail address for sending iMessages to you, you’ll need to make sure you update them with your new e-mail address, since messages destined for the original e-mail address will still go to your sister’s iPhone.
You can also assign additional e-mail addresses here for iMessage, although if you had a personal e-mail address previously associated with iMessage under your old Apple ID, you will need to first remove it from the old Apple ID before you will be able to add it to the new Apple ID. You can do that either from your sister’s iPhone, or simply by logging in with the old Apple ID at http://appleid.apple.com.
.
