How to Add a PIN to your Windows 10 Mobile Phone
You can create a PIN (Personal Identification Number) to use in place of passwords. Having a PIN makes it easier to sign in to your phone, apps, and services.
This tutorial will show you how to add a PIN to your Windows 10 Mobile phone.
In Windows 10 Mobile, when a user enters their PIN code wrong four times, the user will be prompted with a new screen asking them to enter the challenge phrase "A1B2C3." The user is not given another attempt at the passcode until the this challenge phrase is entered, effectively putting a stop any future accidental or purposeful attempts to enter it wrong. If the user were to enter the challenge phrase correctly and proceed to incorrectly enter the wrong PIN once more, the phone will lock and require a restart.
EXAMPLE: Sign in with PIN on Windows 10 Phone
1. Open Settings, and tap on Accounts. (see screenshot below)
2. Tap on Sign-in options. (see screenshot below)
3. Tap on the Add button under PIN. (see screenshot below)
4. Enter your Microsoft account password, and tap on Save. (see screenshot below)
5. Enter at least a minimum 4 digit PIN number you want, and tap on OK. (see screenshot below)
6. You have now added a PIN to your phone.
7. Select when should your Windows 10 phone require you to sign in again under Require sign-in. (see screenshots below)
8. If you like, tap on the Start button at the bottom of your phone to go back to your Start screen. (see screenshot below)