Directly blocking core phone functionalities like Phone and Messages in the same way you restrict third-party apps isn't typically how they are designed.
For Message and Camera

For Phone (Voice Call over Cellular)

Ensure Messages & FaceTime are removed from Always Allowed under Screen Time
With Downtime, you can block apps and notifications for specific periods when you want time away from your devices, or when you want to schedule time away for ...
Use Screen Time on your iPhone or iPad
However, you can significantly limit their impact and access using Screen Time and other built-in features. Here's a breakdown of what you can do for each:
- Phone App:
- Limit During Downtime: You can restrict access to all apps you've selected during scheduled Downtime. While you can't single out the Phone app to be blocked while allowing others, you can make it unavailable during specific periods (e.g., study time, bedtime). To do this:
- Go to Settings > Screen Time.
- Tap Downtime.
- Toggle Turn On Downtime Until Tomorrow (or customize the schedule).
- Choose All Apps & Categories.
- During Downtime, only apps you've explicitly allowed in the "Always Allowed" section will be accessible.Make sure Phone is not in this list.
- Allow Specific Contacts: Even during Downtime or App Limits, you can allow calls from specific contacts. This ensures important calls can still come through.
- Go to Settings > Screen Time.
- Tap Always Allowed.
- Under the "Allowed Contacts" section, choose Specific Contacts.
- Add the contacts you want to allow calls from.
- Silence Unknown Callers: This feature can help reduce interruptions from unwanted calls.
- Go to Settings > Phone.
- Scroll down and tap Silence Unknown Callers.
- Enable this feature. Calls from numbers not saved in your contacts, recent outgoing calls, and Siri Suggestions will be silenced and sent to voicemail.
2. Messages App:
- Limit During Downtime: Similar to the Phone app, you can restrict access to the Messages app during scheduled Downtime by selecting "All Apps & Categories." Ensure Messages is not in the "Always Allowed" list.
- Limit Usage with App Limits: You can set a daily time limit for the Messages app. While this doesn't block it entirely, it restricts the amount of time it can be used.
- Go to Settings > Screen Time.
- Tap App Limits.
- Tap Add Limit.
- Select Social Networking (Messages might be categorized here) or individually select Messages.
- Set the desired time limit and tap Add.
- Notifications Control: Reduce distractions by managing notifications from the Messages app.
- Go to Settings > Notifications > Messages.
- Customize the Alerts style (None, Banner, Lock Screen), disable sounds, and manage other notification settings.
3. Camera App:
- Limit During Downtime: You can include the Camera app in the "All Apps & Categories" restriction during Downtime.
- Limit Usage with App Limits: You can set a daily time limit for the Camera app.
- Go to Settings > Screen Time.
- Tap App Limits.
- Tap Add Limit.
- Select Creativity or Photography & Video (Camera might be categorized here) or individually select Camera.
- Set the desired time limit and tap Add.
- Content & Privacy Restrictions (More Extreme): For a more stringent approach, you can disable the Camera entirely through Content & Privacy Restrictions. However, this is usually intended for younger users and might have broader implications.
- Go to Settings > Screen Time.
- Tap Content & Privacy Restrictions.
- Toggle it On.
- Tap Allowed Apps.
- Toggle Camera to Off. This will remove the Camera app icon from the Home Screen. To re-enable it, you'll need to go back to this setting.
Important Considerations:
- Screen Time Passcode: Make sure to set a Screen Time passcode that the user doesn't know to prevent them from changing these settings.
- Communication Needs: Carefully consider the implications of restricting Phone and Messages, especially for safety and essential communication. The "Always Allowed" contacts feature is crucial in such cases.
- Age Appropriateness: The level of restriction should be appropriate for the age and maturity of the individual.
- Open Communication: It's always best to have an open conversation about why these restrictions are being put in place.
While you can't achieve a direct "block" in the same way as third-party apps, these Screen Time features offer significant control over how and when the Phone, Messages, and Camera apps can be used, helping to minimize distractions and promote focus.