When you set up an iOS device running iOS 9, you are prompted for a six-digit passcode. However, you may not know that you can use a stronger alphanumeric password–one that uses letters and numbers–on your iOS devices. We’ll show you how.
To change to an alphanumeric passcode on your iOS device, tap “Settings” on the Home screen.
On the Settings screen, tap “Touch ID & Passcode”.
Enter your current numeric passcode on the Enter Passcode screen.
On the Touch ID & Passcode screen, tap “Change Passcode”.
Enter your old (or current) passcode again on the Change Passcode screen.
Now, instead of entering a new numeric passcode, tap “Passcode Options”.
Three options display allowing you to set a 4-digit numeric code (as used in iOS prior to version 9), a custom numeric code (allowing for a longer numbers-only code), or a custom alphanumeric code. Tap “Custom Alphanumeric Code”.
Enter your new alphanumeric passcode and tap “return” on the keyboard or “Next” in the upper-right corner of the screen.
Enter your new alphanumeric passcode again to verify it.
Now, when your iPhone is locked, you’ll be provided with a keyboard to enter your alphanumeric passcode.
You can also use this same procedure to change back to a six-digit passcode, or change to a four-digit passcode (not recommended), or to a custom length numeric passcode.