Why is iMessage combining two contacts into one thread. I can only text back the last one that messaged me. This started with iOS 12

Well, set aside the negativity for a moment and imagine if what I said is true -- that the Apple ID is now meant to unify various points of contact for a single person. That would mean that the person would receive the same iMessage on all their devices that use that ID, regardless of phone number or alternate email associated with the ID, and all people who had contact with this person would see their iMessages from various phone numbers/emails combined into one thread. Sounds familiar, right?

If there is any fault, it is that the replies among family members using the same ID are inconsistent, where replies seem to go to the family member who last contacted you (or something of the sort). If you think about it, if the intent is "one ID per person", you'd be messaging yourself in this scenario, so quirky things might be expected.

I realize that the effect of this is undesirable for many here, but it seems to be operating exactly as intended (with exception of the aforementioned inconsistency of messaging between users with the same ID).

Thanks IdrisSeabright. Called in, spoke to a seemingly knowledgeable senior tech who communicated the following:

• Apple engineers are aware of this issue, and are working on a release / fix - did not mention timing
• Indicated expectation that this should solve the issue
• Suggested moving off shared AppleID, thought that should fix it (though I told her that's not what people in this thread think...and my wife whose on her own was / is having similar issues), but again, she said once they come out with a fix, it should resolve for those whose phones are set up correctly even on a shared AppleID

I really don't want to get mired in an AppleID debate, but I share below for those interested. She is not a senior product manager at Apple, but she seemed knowledgeable, so take this for what it's worth as it relates to shared AppleID:

• Indicated Apple does not recommend using same ID across multiple people / phones
• That said, they know people do it, its their ID, they can do what they want with it, and Apple does indeed try to support whatever people do. Some things are not solvable / supportable (shared content issues, etc.), but they will always try to help support / solve an issue. Also acknowledged with young kids, sharing an AppleID is what a lot of people do to control / find, etc.
• Again, indicated that once the fix comes out, if the phones are set up correctly (send / receive and initiate messaging settings) this issue should go away

She indicated that there are some calls about this, but it doesn't strike her as a huge issue - so if you haven't yet, perhaps call in, or click the button on top right as suggested and have them call you... Hopefully in a few days this will all be fixed regardless.

This isn’t even about sharing a ID. To the system it’s just another device, it has 0 knowledge on who is holding and using the device. I wish people would stop spreading this news of separate ID’s as the cure all. The problem lies in iOS. The “send and receive messages from this number” setting is broken. Heck, someone’s answer earlier when I mentioned about a work and personal phone was that I should have two different ID’s, yeah, ok.

That being said, what has worked for me was deleting any message threads I had with anyone using a iOS device and starting fresh that way. I have been going for a few weeks now “sharing” a ID and have no problems.

There's no problem syncing multiple devices to the same Apple ID. The problem is syncing different people to the same Apple ID. I have 5 devices sharing my Apple ID, but they are all mine. My wife has 3 syncing to the same Apple ID, but it is her Apple ID, not mine. And we link them with Family Sharing, and thus share calendars and photos. But we also have content that is unique to each of our needs. And our texts never get confused.

After reading every post in this thread in an attempt to solve this, I think there is a big communication issue in referring to Apple ID's in general when they come in two variations. I believe that some people on here are referring to a main Apple ID and some are referring to sub accounts or aliases under a main Apple ID. Not to mention the fact that your Apple ID could be one thing for iCloud backups, another for the iTunes store, another for iMessage, etc...

Let's say we're exclusively talking about the Apple ID's for iMessage as that is what this problem is referring to. The posts saying "don't share an Apple ID, change that to solve the problem, doing that is wrong" would be correct in that you should not simply share one main Apple ID between different devices for different users in regards to iMessage. However, there is the scenario where you create an Apple ID, say it's called ID 1, and then sub accounts under that ID, say they're called Sub 1, Sub 2, and Sub 3. Let's then say you have a Macbook the family shares, an iPhone exclusive to one user, and an iPad that the family shares. I have this basic scenario myself and was told over the course of a few years by Apple reps in person and through phone support that having them all sign in with ID 1, then having each individually use the sub accounts so that Macbook = ID1 Sub 1, iPhone = ID 1 Sub 2, and iPad = ID 1 Sub 3 for iMessage is appropriate and will be successful. Side note - This is my setup for iMessage; all use different ID's for iCloud backups.

This has been the case until iOS 12. So, before I would get a separate iMessage text thread between each device. Now they come through randomly under the same thread. I would additionally argue that this is in fact an Apple bug rather than expected behavior based on incorrect user use of Apple ID's because there is no consistency. ID 1 Sub 1 and ID 1 Sub 2 devices could both send messages to someone and come in overlapped in one thread, while ID 1 Sub 3 sends one that comes in separately. And the messages coming through in one thread, the contact showing, or otherwise is seemingly random rather than consistent.

If Apple wants to discontinue support for the feature of having sub ID's under an Apple ID, then that is their choice. However, as it is still supported and a viable feature, this should not be happening.

This will happen if the person you are texting with shares an Apple ID also. And location doesn't matter with Apple ID. If the Messages app is signed into the same Apple ID on 2 devices this can be the result.

Hopefully by putting out a definitive "works as designed" statement.

Don't share AppleIDs, ever.

If they are using the same account for iTunes purchases that means by definition they are sharing an AppleID.

Don't do that.

Apple has NEVER supported shared Apple IDs.

I am so glad that I did not follow the advice from "high level" people on this forum and delete years of information. The software update to iOS 12.1 has fixed what Apple referred to as an issue.

This is happening to me too. I’m glad I’m not the only one experiencing this. So far it has done this to me four times since installing iOS 12. Originally on my iPhone 7Plus and now my iPhone XS. The only contacts that it is doing this to me are my mother and father. They have separate apple IDs and separate phone numbers. I can have a thread with my mother and suddenly my father’s thread is gone and if I try to crest a new one it automatically reverts to the thread with my mother. His name or contact info is not on the thread at all. The only fix I have found is to delete the thread, delete both their contacts, then create new contacts for them and open new threads. That works for a couple days and then this again. It’s not that I have anything to hide from them, but it’s annoying and sometimes there’s things were discussing that the other wouldn’t know or care about.

Any ideas for a permanent fix or word from Apple on the matter?

KiltedTim wrote:

Because the devices have not yet been set up properly.

For each person with a new iCloud account, follow the procedure here, then have them set them up from scratch using their own account.

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support

That's ridiculous! My family members have tons of information that they can't lose! Apple must fix this or to Android it is!

You know what KiltedTim, despite the fact that you are a level 10 person in this community you are not helping anyone with your comments.

We are ALLOWED to use a single ID for more than one person, this is a fact and you ranting at us over and over to stop doing this is not going to solve the root problem here even if it solves the issue for individuals. Some of us have a use for two people on a single ID and until Apple actually tells us we can no longer do it we may continue to do so.

There is a problem with IOS12, it is merging threads that come from the same Apple ID and it is going to continue to do so until Apple fixes it ... or tells us that this is what they intended with IOS12 and we will all have to make hard choices at that time. In my calls with Apple they have confirmed that in the release documentation there is no stated intent to do any of this ... which means this is unintended ... or in other words, a bug.

For those out there that are blowing away their phones trying to solve this ... none of it works so far, just delete the threads when they get merged and start new ones, this works for a bit and then they get merged again; so far, nobody has had any better luck. To reiterate, resetting your phone and losing everything is not helping.

Oh, and for those that might not have noticed yet, I can confirm that it is phones that have upgraded to IOS12 that is merging threads from people that may or may not have upgraded themselves; in other words, some component of IOS12 (whether or not it is local to the phone or server side to support IOS12) is doing this. I have family that are not yet on IOS12 on their devices that are not having a merging problem with the same people that I (and other family members) that are on IOS12 are (having the merging problem).

Keep calling Apple guys, as KT and others have told us more than a few times, these are forums for users to help each other and we cannot expect Apple to be reviewing these threads.

I suspect, but do not know for sure, that the iOS caches the AppleID info for existing conversations, which would explain why once changed to separate AppleIDs, some have reported success in deleting any existing threads of conversation with their family members and things remain separated once new conversations begin.

Message combining among users who share AppleIDs is not a carrier issue, it's an iOS issue and the behavior may very well be judged "not a bug" as the reasons people share AppleIDs is the reason Family Sharing was invented.