How can I turn off / lock in-app purchases on the iPhone?

How can I turn off / lock in-app purchases on the iPhone?

Sometimes you need to make sure the people using your iPhone aren't running up the App Store bill. The option to switch off in-app purchases altogether is handy, especially if young children regularly use your iOS device. To lock in-app purchasing follow these steps:

1. Navigate to Settings -> General -> Restrictions -> Enable Restrictions

2. Enter a passcode for Restrictions. You will be asked to enter it twice.

3. Scroll down to the Allowed Content section.

4. Select In-App Purchases -> OFF.