iOS Internals · iCloud & Your Apple Account · Lesson 4 of 5

Find My & Activation Lock

Find a lost iPhone, lock it down, and check a used one before you buy.

Finding a missing iPhone

Find My is Apple's service for locating your devices. On iPhone you switch it on in Settings, tap your name, then Find My, then Find My iPhone. When your phone goes missing, open the Find My app on another Apple device, or sign in at iCloud.com/find, to see it on a map, play a sound or take stronger action.

What if the phone has no Wi-Fi or mobile signal? Find My has a clever backup called the Find My network. A missing device sends out short-range Bluetooth signals. Any Apple device passing nearby, such as a stranger's iPhone on the bus, can pick up that signal and pass the missing device's approximate location to iCloud for its owner. Apple built it with privacy in mind:

• the location is encrypted so that only the owner can read it, and Apple says the whole exchange is end-to-end encrypted and anonymous
• Apple says it doesn't know who the finder is
• the Bluetooth signal switches to a new key about every 15 minutes, so it can't serve as a long-term tracking ID

If the phone doesn't turn up quickly, use Lost Mode, which the Find My app calls Mark As Lost. It:

• locks your iPhone, so it needs your passcode to open
• shows a message and a phone number on the Lock Screen, so an honest finder can call you
• suspends Apple Pay on the device
• keeps tracking the phone's location

Lost Mode is the right first step for a phone you think you just left somewhere. It doesn't delete anything, so if the phone comes back, you unlock it with your passcode and carry on. Apple also emails you to confirm that Lost Mode is on, which is useful to know, because a scammer might send a fake version of that email.

If your phone was stolen, don't try to track down the thief yourself. Report it to the police and your carrier, change your Apple Account password if you think someone knows your passcode, and let Find My and Activation Lock do the work.

Activation Lock and erasing

Turning on Find My also switches on Activation Lock. Apple stores your Apple Account on its activation servers and links it to your iPhone. From then on, your Apple Account password is needed before anyone can turn off Find My or set the phone up again after it's been erased.

That's why Activation Lock makes stolen iPhones much less valuable. Even if a thief wipes the phone, it restarts to a screen asking for the owner's Apple Account. On iOS 15 and later that screen says iPhone Locked to Owner. Without the password, the thief can't set it up as a working phone, so it's hard to resell. Apple says Activation Lock can keep your device secure even in the wrong hands, and improve your chances of getting it back.

If your phone is gone for good, Find My offers Erase iPhone, which wipes your data remotely. If the phone is offline, the erase starts the next time it connects, and you can cancel the request if the phone turns up first. Activation Lock stays on afterward, so the phone is still useless to a thief. Erasing is a last resort, though. Apple notes that after an erase you may no longer be able to locate the phone or play a sound on it. Mark it as lost first, and erase only when you've given up on getting it back.

Activation Lock also protects you as a buyer. Before you pay for a used iPhone from anyone other than Apple or an authorized reseller, check it in person:

• If it shows iPhone Locked to Owner, or setup asks for someone else's Apple Account, it's still linked. Walk away.
• If it opens to a passcode Lock Screen or the Home Screen, it hasn't been erased. Ask the seller to sign out of their Apple Account and erase it while you watch.
• If it shows the Hello setup screen, it's ready for a new owner.

Selling your own iPhone? Sign out of your Apple Account first, which turns off Find My and Activation Lock. Then erase it in Settings, General, Transfer or Reset iPhone.