how to restrict to access to settings with a pass code

[_Thor_]

OK here is my dilemma, I am trying to keep my data usage down on my child's phone, I have tried Family Base but it requires that the parent device have a data allowance setup as well as the child device. Parent device is used for business so this will not do. I have tried restrictions but child is still able to turn on cellular data after it's been turned of and restrictions are set to "Do not allow changes". I need for the child's iPhone to use data type apps only when connected via WiFi connection only. So asking if there is a way to restrict access to the settings by way of a pass code so that the child is unable to access the settings.

[nicholasbranson · Accepted solution]

I'd just use family base. You can set up the parent line to warn you when you hit a limit but not cut you off.

On the usage limits page you should observe a checkbox. That checkbox is what will restrict your phone from exceeding the provided limit amount. As long as that box is NOT check your line will not be restricted.