You can prevent accidental purchases on your Android device from the Play Store app by turning on authentication. Authentication means certain information, like a password, must be entered on your device to make a purchase.
To do so, perform the following:
- Open the Google Play Store app.
- Tap 'Menu' > 'Settings'.
- Tap 'Require authentication for purchases'.
- Select 'For all purchases through Google Play on this device'.
- Authentication will now be required for every digital content purchase.
Note: To change authentication settings you will need your Google password.