I’m upgrading my iPhone and trading in the old one. I had to erase the old one completely and unhook “Find my iPhone” from it.

I’d seen headlines hinting that recycled iPhones aren’t often erased. Some headlines suggest that the erasing operation itself doesn’t really work.

It works. It’s just time consuming. I turned off TouchID and the lock code. I disabled “Find my iPhone” and all the iCloud connections. Then I went on line and made sure the old phone wasn’t listed on my Apple account. Finally, I hit the “Erase All Contents and Settings” option.

The phone restarted with the Hello setup screen. I went through guided setup without hooking up iCloud or anything personal. I looked through the phone to make sure nothing was there. It was clean. I looked on Find My iPhone, and the old phone didn’t appear.

Apple has been trying to use “Find my iPhone” in iCloud as a way to disable stolen phones. If you use the “Find” feature and don’t turn it off before recycling your phone, the buyer might not get the phone working again. I was offered about $150 less for my phone if I forgot to turn off “Find my iPhone.”

The Basic Steps

Here are the basic steps:

1. Be sure the phone is connected to the Internet. If you’ve already activated your new phone, set up the old one to use whatever Wi Fi is nearby.
2. Turn off “Find my iPhone.” Go to Settings -> iCloud. Scroll down and look at the “Find my iPhone” entry. If it says “On,” click on it. Click the green “Find my iPhone” switch. It will demand your iCloud password, and won’t turn it off until you provide it. If the switch remains green, the Find feature is still on. Try again until the switch turns white and stays white.
3. Go to Settings -> General -> Reset -> Erase All Contents and Settings. A note will explain that the command erases all contents and settings. It will demand that you confirm this choice a couple of times.
4. Turn off the phone completely (“Slide to power off”) and remove the SIM card.
5. Visit icloud.com. Click on Find iPhone, and select your iPhone from the “All Devices” list. Click “Play Sound” and make sure the old phone doesn’t make a sound. If you have several iPhones, try them all.

Only Steps 3 and 4 remove your personal data. The other steps unhook you from “Find my iPhone” and make sure you’re really unhooked.

For The Paranoid

I took a few extra steps just because I’m paranoid:

1. I manually deleted all the fingerprints in TouchID. I disabled my passcode. This is all under Settings.
2. I turned off “Find my iPhone.” It took me several tries. I might have mistyped my icloud password, or I might have erased the local Wi Fi password, or both. So I made sure I was connected to Wi Fi and that I knew my password. It eventually worked.
3. I went online and made sure the phone was deleted from both icloud and from my Supported Devices list at the Apple web site. Here’s the URL for the latter: https://supportprofile.apple.com/.  For some reason, Apple doesn’t display this link in obvious places on its web site. I usually have to use Google. Look for your old phone. Double check its serial number against those of your registered devices. Be sure it has been deleted.
4. I went into Settings -> iCloud on my phone. I disabled all the services and logged out of iCloud.
5. I deleted my email settings.
6. I selected Settings -> General -> Reset -> Erase All Contents and Settings. I confirmed it and waited for the phone to restart.
7. I went through Guided Setup. The only password I provided was for my local Wi Fi. I skipped all iCloud, iTunes, and App Store logins. I skipped TouchID and the passcode. I looked through the phone for any of my old data. Nothing found.
8. I selected my network under Settings -> Wi-Fi. I clicked on the “i in a circle” logo. I then selected “Forget this Network” to erase the Wi Fi password. You may also/instead select Settings -> General -> Reset -> Reset Network Settings.
9. I turned off the phone completely (“Slide to power off”) and removed the SIM card.

No doubt this was overkill. I keep my phone encrypted. The “Erase All Contents and Settings” operation simply erases the master crypto key and makes the phone start over with a new one. This turns the previous contents to gibberish, except for whatever remains on the SIM card.

Additional Inactive iPhone Notes

[added to the posting later]

I haven’t played much with a deactivated iPhone before this. Here are some observations.

• I couldn’t go through iPhone setup without a SIM installed. The setup connected to Wi Fi but stopped dead before going much further.
• Once I installed the SIM, setup continued without re-prompting for the Wi Fi password provided earlier.
• Once setup was complete, I could power off the iPhone, remove the SIM, and use it as an almost-iPod Touch. The phone would occasionally display unhappy alerts about the SIM’s absence, but seemed to work otherwise.
• I lack the tools to confirm that the device wipe (“Erase All Contents and Settings”) really and truly resets the internal crypto key as claimed. But the results I observed were consistent with the claim.