Works for Proton Calendar whether or not it has its own passcode. No download needed.
Touch and hold Proton Calendar's icon, tap Require Face ID, then confirm. On iOS 18 and later that puts Proton Calendar behind Face ID, Touch ID or your passcode; choose Hide and Require Face ID instead to move it into App Library's Hidden folder as well.
Lock Proton Calendar with Face ID
- Find Proton Calendar on your Home Screen or in App Library.
- Touch and hold the icon until the quick-actions menu opens.
- Tap Require Face ID (or Require Touch ID / Require Passcode, depending on your iPhone).
- Tap Require Face ID again to confirm. Proton Calendar now asks for authentication every time it opens.
To test it, close Proton Calendar from the App Switcher and open it again. You should see the Face ID prompt before any content appears.
Hide Proton Calendar in App Library
- Touch and hold Proton Calendar's icon and tap Require Face ID.
- Choose Hide and Require Face ID instead of Require Face ID.
- Confirm. The icon leaves your Home Screen and moves to the Hidden folder at the bottom of App Library.
- To open it later, swipe to App Library, tap Hidden and authenticate.
Hiding also locks the app. To undo either, touch and hold the icon again and choose Don't Require Face ID.
Why lock Proton Calendar?
Proton Calendar is a secure email app, the kind of app that tends to hold personal information you would not want on screen if someone borrows your unlocked phone. Email apps see every message and contact. Third-party mail clients may route mail through their own servers to offer features like push or AI summaries.
Productivity apps tend to collect the work you do in them — documents, notes and files — so User Content is common. The question is whether it syncs to the developer's servers and how it is protected there.
A lock answers one question — who can open the app on this iPhone. It does not change what Proton Calendar sends to its developer; for that, see Proton Calendar's full privacy report.
What the lock does and does not do
It does
- Ask for Face ID, Touch ID or passcode every time Proton Calendar opens
- Hide message previews in notifications
- Keep Proton Calendar's content out of Spotlight and Siri suggestions
- With Hide, remove the icon from the Home Screen
It does not
- Stop someone who knows your passcode
- Encrypt or change how Proton Calendar stores data
- Sync to your iPad or other devices
- Remove Proton Calendar from purchase history or Screen Time reports
Don't see Require Face ID?
- Update to iOS 18 or later in Settings › General › Software Update.
- Make sure a passcode is set in Settings › Face ID & Passcode; the lock needs one.
- Some Apple apps (Settings, Calculator, Camera, Maps, Find My, Clock) cannot be locked or hidden.
- If your iPhone is managed by work or school, the option may be restricted.
Other settings worth checking for Proton Calendar
Notifications
Settings › Notifications › Proton Calendar › Show Previews: When Unlocked keeps message and account details off the Lock Screen.
Proton Calendar's full privacy label
None declared
None declared
Lock these apps too
After you lock Proton Calendar
Done. You have applied every control the label points to.
FAQ
Does Proton Calendar have its own passcode?
What happens to Proton Calendar's notifications when it is locked?
Can someone who knows my passcode open a locked app?
Is a locked Proton Calendar encrypted?
Why can't I see the Require Face ID option?
Does hiding Proton Calendar remove it from my purchase history?
Is Proton Calendar safe? Full privacy report →Does Proton Calendar track you? →Lock an app: A–Z →All productivity apps →