How to lock your iPhone with a passcode and make it 'virtually impenetrable' to strangers — from your phone or remotely, if it's lost or stolen

Hollis Johnson/Business InsiderPutting a passcode on your iPhone is a security method worth taking. You can also lock your phone’s screen remotely if it’s ever lost or stolen.

  • You should use a passcode to lock your iPhone, so only you can wake it from sleep and access the data and apps on it.
  • You can set the passcode and the delay before the phone auto-locks from the Settings app.
  • If your phone is lost or stolen, you can use Find My iPhone to put the phone in Lost Mode, which locks the screen (even if you never set a passcode) and shows a message on the lock screen.
  • Visit Business Insider’s homepage for more stories.

Locking your iPhone – which turns off the display and makes a passcode required to turn it back on again – is an easy way to protect your data and personal information.

If you don’t have a passcode enabled on your phone, you’re missing out on a virtually impenetrable way to prevent strangers from accessing your phone if it gets lost or stolen. And it keeps your phone safe from run-of-the-mill prying eyes as well.

In addition to enabling the passcode, you may want to adjust the time it takes the iPhone to auto-lock. You can choose a time from 30 seconds to 5 minutes.

How to lock your iPhone using a passcode

1. Start the Settings app.

2. Depending upon which model iPhone you have, tap “Face ID & Passcode” (for iPhone X or later), “Touch ID & Passcode” (for iPhones 5s and later) or “Passcode” (for the iPhone 5 or older).

3. Tap “Turn Passcode On.”

Lock 1Dave Johnson/Business InsiderYou should enable the passcode for your iPhone, since it provides almost effortless security.

4. Enter a six-digit passcode that you’ll enter whenever you want to unlock your phone. If you don’t want to use the default 6-digit number, first tap “Passcode Options” and choose the kind of passcode you want to use: an alphanumeric password, a 4-digit number, or a custom number.

Lock 2Dave Johnson/Business InsiderYou have a lot of choices for how long and complicated to make your passcode. Most people use either a four- or six-digit numeric code.

5. Confirm the passcode by entering it a second time on the verification screen.

6. Your iPhone may ask you to enter your Apple ID password. This allows you to use your new passcode instead of the Apple ID password for some tasks.

Your phone now has a passcode assigned to it, which means when it turns off automatically after a couple of minutes, or when you turn it off immediately with the Power button, it will be locked and require a passcode to wake.

Change the time to auto-lock

1. Start the Settings app.

2. Tap “Display & Brightness.”

3. Tap “Auto-Lock” and then choose a time from 30 seconds to 5 minutes.

Lock 3Dave Johnson/Business InsiderA shorter auto-lock time is safer, but may be less convenient.

How to lock your phone by putting it in Lost Mode

No one looks forward to losing a phone, but it sometimes happens. The good news is that Apple provides a tool for locking and helping you recover it. When put into Lost Mode, your phone will automatically lock, even if you had never set up a passcode before – though it can only do that if it still has battery life remaining and has access to a phone signal. The lock screen also displays a message of your choice, including as a phone number to call if it’s found.

1. In any web browser, open the Find My iPhone web page.

2. Log in with your Apple ID password.

3. When the map appears, click the device menu at the top of the screen and choose your lost iPhone.

Lock 4Dave Johnson/Business InsiderLost Mode locks your phone’s screen remotely.

4. In the box that appears on the right, click “Lost Mode.”

5. Enter a phone number which will appear on the phone’s lock screen, so if found, you can be notified. Then click “Next.”

6. Enter a message that you want to appear on the lock screen – or accept the default message. Click “Done.”

Lock 5Dave Johnson/Business InsiderYou can create a custom message for your phone’s lock screen. You can offer a reward if it’s returned, for example.

7. Your phone is now locked remotely (assuming it’s in range of a wireless signal).

If your phone is later recovered, you can return to this web page and click “Lost Mode” again. You’ll need to confirm by clicking “Stop Lost Mode” several more times.

Lost 6Dave Johnson/Business InsiderAfter your phone is found, you can turn off Lost Mode, which returns your phone to normal.

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