Your child keeps turning Screen Time off
You set up limits, they lasted two days, and now everything is switched off again. This is the single most common failure in iPhone parental controls, and it has one cause: Screen Time settings that aren't locked can be changed by anyone holding the phone. Including whoever you were trying to limit.
Set the Screen Time passcode
Settings › Screen Time › Lock Screen Time Settings. Choose a four-digit code that is not your device passcode, and that your child has not watched you enter — children are far better at shoulder-surfing than adults expect. iOS will offer to attach an Apple Account for recovery. Accept it. A forgotten Screen Time passcode with no recovery account is one of the more painful things to undo on iOS.
Why this affects third-party apps too
Every parental-control app on iPhone, including Reef, is built on Apple's Family Controls framework — the same machinery behind Screen Time. That's a good thing: it means the shielding is enforced by the system rather than by an app that can be swiped away. But it also means that a child who can reach Settings › Screen Time can revoke the app's authorisation and switch the whole thing off. No third-party app can prevent that, because Settings itself can't be shielded. The Screen Time passcode is what closes the door.
Trim what stays reachable
Settings › Screen Time › Always Allowed lists the apps that stay open no matter what any restriction says. Messages and FaceTime are in there by default. Remove them if you don't want them reachable during a locked session. Phone cannot be removed, deliberately, so emergency calls always work. This list explains a lot of confused reports that a lock 'didn't work'.
If you've forgotten your Screen Time passcode
If you attached an Apple Account when you set it, tap Forgot Passcode on the entry screen and recover it there. If you didn't, there is no supported reset — the only route is erasing the device and setting it up as new, which is exactly as unpleasant as it sounds. Don't set a code you won't remember, and do attach the recovery account.
Match the tool to the age
For a teenager with their own iPhone, Screen Time with a locked passcode is the right structure — it's built for budgets and schedules on a device they own. For a younger child using your phone, a session-based allow-list is a better fit: it starts in one tap, shields everything you didn't choose, and ends with your Face ID. Reef takes the second shape, and it deliberately never paywalls the lock, the PIN or the passcode recovery.
FAQ
How do I stop my child changing Screen Time settings?
Set a Screen Time passcode in Settings › Screen Time › Lock Screen Time Settings, and make it different from your device passcode. Without it, any restriction can be switched off by whoever is holding the phone.
Can a child uninstall a parental-control app to escape it?
Not while it's active, if the app uses Family Controls — Reef can't be deleted during a session, and the shield survives a force-quit and a restart. What a child can still do is open Settings and revoke Screen Time authorisation, which is why the passcode matters.
I forgot my Screen Time passcode. What now?
If you linked an Apple Account when setting it, use Forgot Passcode on the entry screen. If you didn't, there's no supported reset — erasing the device and setting it up as new is the only route.
Is a third-party app stronger than Screen Time?
It isn't stronger — it's the same framework, arranged differently. Screen Time thinks in daily budgets for a device the child owns. A session app thinks in handovers of a device you own. Both depend on the Screen Time passcode to stop being switched off.
Hand over the phone, not the whole phone
Reef shields every app you didn't allow, gives your child a hub of the games and sites you chose, and needs your Face ID to switch off. Free to download — the shield, the PIN and passcode recovery are never paywalled.
Get Reef on the App StoreAbout ReefiOS behaviour described here was checked against iOS 26. Apple moves settings between releases — if a path doesn't match what you see, the feature is usually still there under a nearby name.