Protecting iPhone Duo in public: screens, passcodes and theft

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The Metropolitan Police says thieves use shoulder surfing to watch or film people typing passcodes, and recommends unlocking with your fingerprint or face in public. On iPhone Duo that means Touch ID in the side button, a longer passcode for the times you do type it, and hiding message previews on the Lock Screen.

Quick answer

Unlock with Touch ID or your Apple Watch rather than typing your passcode in public. Set a custom alphanumeric passcode, which Apple calls one of the most secure options. Set Show Previews to When Unlocked, lock banking apps behind Touch ID, keep Auto-Lock short and turn on Stolen Device Protection. Put the phone away when you've finished with it.

Why does a passcode matter more than the screen?

Because the passcode opens everything else. The Metropolitan Police says thieves may steal a phone to get at bank accounts and personal data as well as the device, and that they use shoulder surfing, looking over your shoulder, to watch or film you entering passcodes or see your data. Get Safe Online lists shoulder surfing, people viewing your screen, among the risks of using a phone in public.

If you think someone has already seen your code, start with what to do if someone watched you type your passcode. This guide is about setting up an iPhone Duo so it's less likely to happen.

How do you avoid typing your passcode in public?

Use your fingerprint. The Metropolitan Police advises using biometric authentication, such as a fingerprint, to unlock your phone and sensitive apps in public rather than a passcode, and avoiding entering personal information in a public space.

iPhone Duo has Touch ID in the side button and no Face ID. Apple says it works whether the phone is open or closed, and that you can also unlock iPhone Duo with your Apple Watch.

Apple says you'll still need the passcode after a restart, if you haven't unlocked the phone for more than 48 hours, after five unsuccessful Touch ID attempts, and in a few other cases. So you can't avoid typing it entirely. You can make it harder to read. Setup is in iPhone Duo: Face ID or Touch ID?

What kind of passcode is hardest to shoulder surf?

A longer one. The Metropolitan Police says passwords are harder to shoulder surf than short PIN codes. Apple says the most secure passcode options are Custom Alphanumeric Code and Custom Numeric Code. The NCSC's guidance for small organisations recommends a 6-digit PIN or a strong password, and avoiding guessable PINs like 123456 or 000000.

To change it on iPhone Duo:

  1. Go to Settings > Touch ID & Passcode.
  2. Tap Change Passcode.
  3. Tap Passcode Options, then choose Custom Alphanumeric Code or Custom Numeric Code.

What should the Lock Screen show?

As little as possible. The Metropolitan Police says to turn off message previews so a thief won't see reset or login codes when the phone is locked.

Apple says you can choose when notification previews from one app, or from all apps, appear on your Lock Screen. Its steps for an app:

  1. Go to Settings > Notifications.
  2. Tap the app below Notification Style.
  3. Tap Show Previews, if it appears, then choose When Unlocked or Never.

Apple notes that not all apps support notification previews, and that previews can include text from Messages and Mail.

How do you lock banking apps behind Touch ID?

Apple lets you lock an app so it needs Face ID, Touch ID or your passcode to open. Apple says information inside a locked app won't appear in other places, such as notification previews, search or Siri suggestions.

  1. On the Home Screen, touch and hold the app until the Quick Actions menu opens.
  2. Tap Require Touch ID.
  3. Tap Require Touch ID again to lock it.

Apple says the app locks again automatically after you quit it. The Metropolitan Police recommends securing high-value apps such as banking apps and digital wallets behind biometrics, and asking whether some apps need to be on your phone at all.

What about a privacy screen on the inner display?

Get Safe Online suggests considering a privacy filter, which blocks the view of your screen from people sitting either side of you. On iPhone Duo, check Apple's handling advice before fitting one to the inner display. Apple says the inner display is calibrated for its nano-texture cover layer and that applying an external screen protector can compromise display performance.

Apple also says to remove anything from the inner display before you close iPhone Duo, because folding hard objects such as keys or coins inside it can damage the display.

How do you make a theft less likely?

The Metropolitan Police and Get Safe Online give practical advice for being out with a phone:

  • Don't leave the phone unattended or on a table. The Met says thieves can take a phone from a table in seconds, or distract you to take it.
  • Put it away when you've finished using it, and where you can, don't have it on show while walking around (Get Safe Online).
  • Never give your phone to someone you don't know or have only just met. The Met says thieves may ask to borrow it or offer to type in their number. If it's already happened, see gave your unlocked phone to a stranger.

The Met also says to set Auto-Lock to a short time. Apple's path is Settings > Display & Brightness > Auto-Lock. Our wider guide, how to protect your phone from theft, covers street snatches.

What should you switch on before you go out?

  1. Stolen Device Protection. The Met recommends it on iPhone. Apple says that away from familiar places it asks for Face ID or Touch ID, with no passcode fallback, for things like saved passwords, and adds a one-hour delay to changes such as your Apple Account password. Apple lets you choose Always under Require Security Delay so it applies everywhere. Details: Stolen Device Protection on iPhone Duo.
  2. Find My. You'll need it to turn on Lost Mode if the phone goes missing.
  3. A note of your IMEI. The Met says to dial *#06# and keep the number somewhere other than your phone. Apple says iPhone 14 models and later don't have an IMEI engraved on them.

Where Failshot fits

Touch ID keeps your passcode off the screen most of the time. Your passcode is the first layer. Failshot is the second.

Failshot for iPhone is coming soon. When it's out, you'll turn it on, leave Failshot open on its own screen and lock your iPhone, and whoever unlocks it into Failshot will be photographed. Get early access and we'll email you when Failshot for iPhone is ready.

Failshot for Mac is out now, for macOS 14 or later.

More questions

What is shoulder surfing?

Get Safe Online describes it as people viewing your screen. The Metropolitan Police says thieves use it to watch or film you entering passcodes or to see your data, which is why it recommends biometric unlock in public.

Can I use a privacy screen protector on iPhone Duo?

Get Safe Online suggests a privacy filter for using a device in public. For the inner display, Apple says it's calibrated for the nano-texture cover layer and that an external screen protector can compromise display performance, and not to try to remove the cover layer.

How do I hide notification previews on iPhone Duo?

Go to Settings > Notifications, tap an app below Notification Style, then tap Show Previews and choose When Unlocked or Never. The Metropolitan Police recommends this so a thief can't read reset or login codes on the Lock Screen.

Is a 6-digit passcode enough for iPhone Duo?

The NCSC's guidance for small organisations recommends a 6-digit PIN or a strong password and avoiding guessable PINs. The Metropolitan Police says passwords are harder to shoulder surf than short PINs, and Apple lists Custom Alphanumeric Code among the most secure options.

Can I unlock iPhone Duo without typing my passcode?

Usually. Apple says iPhone Duo unlocks with Touch ID in the side button, open or closed, and with your Apple Watch. Apple still asks for the passcode after a restart, after more than 48 hours without unlocking and after five failed Touch ID attempts.

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