The first minute is the worst part. You pat the pocket, check the bag twice, retrace ten steps, and start running the list of everything that lives on that phone.
The useful actions are few, and they have an order. The trap is that panic points straight at the most destructive one, erasing, which is rarely the right first move.
Here is that order, and why each step sits where it does.
Get to another screen
Everything useful happens in Find My, and you need a device that is not your phone: an iPad, a Mac, or any computer signed in at iCloud.com/find. With nothing to hand, borrow a friend's iPhone: the Find My app's Me tab has a Help a Friend option that signs you in without touching their account.
Look at the map. An online device shows a current location; an offline one shows where it last was, and can still be spotted through Apple's Find My network when another Apple device passes close enough.
A phone sitting in the cafe you just left is a different problem from one moving along a road.
Play a sound before you assume the worst
If the map puts the phone somewhere plausible, use Play Sound. It rings even on silent, and if the device is offline the sound is queued for the next time it connects.
It is easy to skip in a panic, and it is the step that finds phones in sofa cushions and coat pockets.
Do not chase a moving dot. A location you do not like the look of is something to give the police, not an invitation to knock on a door.
Mark As Lost does the most work
If the phone is not simply mislaid, use Mark As Lost, also called Lost Mode. It is the strongest action available while you still hope to get it back.
It locks the phone with your passcode, or asks you to set one if it had none. It suspends Apple Pay and cards in Wallet, stops notification previews, and puts a message and phone number of your choosing on the locked screen, so whoever found the phone can reach you without getting into it.
You can also ask to be notified when it is located again, so the map does the waiting.
Do not remove the device from your Apple Account
This is the mistake that cannot be undone. Removing an iPhone from your account, from the Find My device list or your Apple Account page, switches off Activation Lock, which is what makes a stolen iPhone unusable to anyone else. Leave it on your account after you erase it, after you buy a replacement, and however firmly a message says removal is required. Take it off only when the phone is back in your hands or you are selling it.
Lock down the account, not just the phone
Your Apple Account is a bigger target than the phone: it holds your backups, your photos, and the switch that turns off Find My.
From the device you are already using, change your Apple Account password: on an Apple device, Settings, your name, Sign-In and Security; in a browser, account.apple.com. Changing it does not turn off Find My or Activation Lock, so do it straight away.
If that password is reused anywhere, change it there too. Someone holding both your phone and your passcode may be able to reach saved passwords, which is what Stolen Device Protection, available from iOS 17.3, is built to prevent.
Report it in three places
The police first. Give them the serial number or IMEI, found on your Apple Account device list, the box, or a receipt. The report number is what an insurer will ask for.
Then your carrier. They can suspend the line so calls and data cannot be run up on your account, and move your number to a new eSIM.
Then insurance. With AppleCare Plus with Theft and Loss, check the claim conditions first: that cover depends on Find My having been on and the device staying on your account.
Erase last, not first
Erase This Device wipes the phone remotely. It is right once you have accepted it is not coming back, or if it holds work data you cannot leave out there.
Two things to know. On iOS 15 and later an erased iPhone stays in Find My, so location and Activation Lock survive the wipe. But erasing also signs the device out, so the Lost Mode message and number stop helping an honest finder return it. Hence the order: Mark As Lost first, erase later.
The message that arrives the next day
Expect a text or email saying your iPhone has been found, with a link to sign in to iCloud. Those messages are after your Apple Account password, which is what removes Activation Lock and turns a locked brick into something sellable.
Apple does not ask for your password through a link in a message. Check the Find My app, or reach iCloud.com/find by typing the address yourself, and ignore the rest.
Set Find My and Stolen Device Protection on the replacement before anything else. If you want a lock screen that warns people off as well, DON'T Touch Phone Wallpapers is an easy way to set one up on day one.
Quick answers
Can I track my iPhone if it is switched off?
Often, yes. Recent iPhones can report location through Apple's Find My network for a period after being powered down, though support varies by model and iOS version. Check the map more than once.
Does Lost Mode stop someone using the phone?
It locks the device behind your passcode, and Activation Lock means it cannot be set up as a new phone without your Apple Account details. Someone who already knows your passcode is the exception, which is what Stolen Device Protection addresses.
Should I erase straight away?
Only if the data matters more than recovery, or your workplace requires it. Erasing removes your Lost Mode contact message, so give the phone some time to be found first.
What if I did not have Find My turned on?
Then you cannot locate or lock it remotely. What remains is changing your Apple Account password and reporting to police and carrier so the line is suspended. Turn Find My on for the replacement as soon as you set it up.
Where to get it
Once the replacement is set up, DON'T Touch Phone Wallpapers has an HD library of warning and aesthetic lock screens, blunt to minimal, framed for the iPhone lock screen.
It will not stop a theft, and nothing on a screen can. What it does is speak to whoever is holding your phone, which is worth having on top of the settings that do the real work.