Unauthorized in-app purchases can be prevented by adjusting the settings to require a PIN number or passcode to complete a transaction.
- Open "Google Play Store" app.
- Open the menu and tap "Settings".
- Under User Controls, select "Require password for purchases".
- Tap to select "For all purchases through Google Play on this device".
- Confirm your Google Play Store password and tap "OK".
- From the Home menu, tap the "Settings" icon.
- Select "General" from the left column.
- Scroll down and select "Restrictions" in the right column.
- Tap on "Enable Restrictions".
- You will be prompted to enter a 4-digit Restrictions Passcode. Confirm your passcode to set.
- In the "Allow" section, tap on "In-App Purchases" to turn ON/OFF.
Windows 8 Phone
- Open the "Store" app.
- Tap ... to open "Settings"
- Select "PIN" and tap the toggle.
- Turn "Wallet PIN" from "OFF" to "ON" by sliding the bar.
- When prompted, enter a PIN code and select "Done".
- Check "Use Wallet PIN to protect music, app, and in-app purchases".