NICEVILLE, Fla — In this week’s edition of It’s Geek To Me, Jeff Werner explains why an older iPhone 8 and a newer iPhone 15 can end up sharing call history and activity, and what Apple users can do to separate the devices.
Niceville.com Community Partner
QUESTION:
William R. from Fort Walton Beach asks:
Expanding the paradigm to Geekdom into cell phones (if you can). My old iPhone 8 died as far as Verizon was concerned, rendering it to just a WiFi device. Consumer Cellular came along, sent me a mini-SIM card, and voila, iPhone 8 works as a phone on their network with a new number. The iPhone 15 that I got to replace the iPhone 8 has kept my old number. Both phones work outgoing & incoming calls on their distinct numbers. That said, every call made and received on the iPhone 15 also appears on the iPhone 8, along with the calls to and from the iPhone 8 itself. Oddly enough, calls to and from the iPhone 8 do not mirror onto the iPhone 15. Any ideas?
ANSWER:
Jeff Werner responds:
Well, now, William, what makes you think that cell phones are an expansion? This clearly falls into the realm of technology, and I shifted my paradigm a long time ago from this being a column about Windows to one about “Computers and Technology.” Do I have any ideas? Well, I always have ideas. Let’s see whether they pan out.
Let me start by congratulating you on giving that venerable iPhone 8 a brand-new lease on life. Many people don’t even realize that a Smartphone will continue working via Wi-Fi without being connected to a cellular carrier, sans telephone capability, of course.
But you took it a step further. Keeping older hardware out of the landfill by switching to a budget-friendly carrier like Consumer Cellular is an excellent choice. It proves there is plenty of use left in that old device.
What you are experiencing isn’t a glitch, a carrier error, or a ghost in the machine. It is a textbook case of Apple’s ecosystem being just a little too smart for its own good.
To understand why this is happening, we need to raise the hood on a set of Apple features collectively known as Continuity. Continuity is designed to make your tech life seamless.
The core philosophy is that if you own multiple Apple products—say, an iPad, a Mac, and an iPhone—you should be able to answer your phone calls or reply to texts from whichever device is closest to you.
When you set up your new iPhone 15, you likely did what most of us do: you restored it from a backup of your old iPhone 8 or signed into it using your existing Apple ID. By doing so, you tied both devices to the exact same iCloud identity.
Then you slipped that new Consumer Cellular SIM card into the iPhone 8, which caused it to successfully register its new phone number with the carrier network.
Niceville.com Community Partner
But in the background, the iPhone 8 remained connected to your digital profile in iCloud, and part of that is what you are seeing as the glitchy behavior of both devices’ activity appearing on the iPhone 8.
You’re probably wondering why the reverse isn’t true. Here is why the mirroring is strictly a one-way street.
When Apple’s servers look at your primary account identity, they still view your old number (now assigned to the iPhone 15) as the primary phone number for your Apple ID. Because the iPhone 15 is the primary device, Apple’s Continuity framework automatically broadcasts its call logs, FaceTime history, and active cellular calls to every other device linked to that same Apple ID.
Because your iPhone 8 is signed in to that account, it happily catches that broadcasted data stream and displays your iPhone 15’s calls right in its recent calls list.
Niceville.com Community Partner
Conversely, the iPhone 8’s new number is treated like a secondary or auxiliary line. It is an independent cellular line that hasn’t been promoted to the primary slot on your Apple ID profile.
Therefore, Apple’s servers do not broadcast the iPhone 8’s call logs out to the rest of your devices. Your iPhone 15 stays completely quiet when the iPhone 8 rings because it simply isn’t being told about any activity from the other phone number.
Thankfully, you don’t need to be a full-on Geek to tame this over-enthusiastic ecosystem. You have two clear options to fix this, depending on how you plan to use these devices moving forward:
Option 1: Keep the Shared Apple ID but Disable Call Sharing. If you want both phones to continue sharing the same photo library, contacts, and app purchases, you can keep them on the same Apple ID but manually sever the communication link.
Niceville.com Community Partner
On the iPhone 15, open Settings. Scroll down and tap on “Apps”, then select “Phone”. Look for the setting labeled “Calls on Other Devices”. Toggle it to Off, or uncheck the iPhone 8 specifically from the list of allowed devices.
Next, you will want to prevent call logs from syncing via iCloud Drive. On both phones, open Settings, tap your Apple ID name at the very top, select iCloud, look for iCloud Drive, and turn it off. This stops the two phones from sharing a synchronized call history ledger.
Option 2: (The Best Practice Solution) Separate Apple IDs. If the resurrected iPhone 8 is being handed off to a spouse, a relative, or used strictly as an independent second line, the absolute best move is to completely separate their digital identities is to establish a new Apple ID for one of them.
Sharing a single Apple ID between two active phones with two different phone numbers almost always leads to digital headaches. Over time, you will find things getting worse than just calls showing up on an extra device. Your text messages will get tangled, contacts merge unexpectedly, and Safari web browsing histories cross paths.
Niceville.com Community Partner
To completely separate the devices, on the iPhone 8, open Settings and tap your Apple ID name at the top. Scroll to the very bottom and tap “Sign Out”.
Choose to keep a copy of your data (like contacts) on the phone if you need them. Once signed out, select the option to create a brand-new, completely separate Apple ID for the iPhone 8.
By giving the iPhone 8 its own distinct Apple identity, you draw a hard line between the two devices. The iPhone 15 will handle its own business, the iPhone 8 will handle its own calls, and peace will finally be restored to your mobile kingdom.
To view additional content, comment on articles, or submit a question, visit my website at ItsGeekToMe.co (not .com!)
Jeff Werner, a software engineer based in Niceville, Florida, has been writing his popular “It’s Geek to Me” tech column since 2007. He shares his expertise to help readers solve everyday tech challenges.
