Set a passcode on iPhone
For better security, set a passcode that must be entered to unlock iPhone when you turn it on or wake it. Setting a passcode turns on data protection, which uses your passcode as a key to encrypt Mail messages and attachments stored on iPhone with 256-bit AES encryption. (Other apps may also use data protection.)
Set or change the passcode
Go to Settings
, then do one of the following:
iPhone X and later: Tap Face ID & Passcode.
Other models: Tap Touch ID & Passcode.
Tap Turn Passcode On or Change Passcode.
To view options for creating a password, tap Passcode Options. The most secure options are Custom Alphanumeric Code and Custom Numeric Code.
After you set a passcode, you can use Face ID or Touch ID to unlock iPhone (depending on your model). For additional security, however, you must always enter your passcode to unlock your iPhone under the following conditions:
You turn on or restart your iPhone.
You haven’t unlocked your iPhone for more than 48 hours.
You haven’t unlocked your iPhone with the passcode in the last 6.5 days, and you haven’t unlocked it with Face ID or Touch ID in the last 4 hours.
Your iPhone receives a remote lock command.
There are five unsuccessful attempts to unlock your iPhone with Face ID or Touch ID.
An attempt to use Emergency SOS is initiated (see Make emergency calls on iPhone).
An attempt to view your Medical ID is initiated (see Create a Medical ID in Health on iPhone).
Change when iPhone automatically locks
Go to Settings > Display & Brightness > Auto-Lock, then set a length of time.
Erase data after 10 failed passcodes
Set iPhone to erase all information, media, and personal settings after 10 consecutive failed passcode attempts.
Go to Settings
, then do one of the following:
iPhone X and later: Tap Face ID & Passcode.
Other models: Tap Touch ID & Passcode.
Turn on Erase Data.
After all data is erased, you must restore your device from a backup or set it up again as new.
Turn off the passcode
Go to Settings
, then do one of the following:
iPhone X and later: Tap Face ID & Passcode.
Other models: Tap Touch ID & Passcode.
Tap Turn Passcode Off.
Reset the passcode
If you enter the wrong passcode six times in a row, you’ll be locked out, and you’ll receive a message that says iPhone is disabled. If you can’t remember your passcode, you can erase your device with iTunes or with recovery mode, then set a new passcode. (If you made an iCloud or iTunes backup before you forgot your passcode, you can restore your data and settings from the backup.)
See the Apple Support article If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled.