Why your iPhone blocks apps and how to unblock them

When you install an app from outside the App Store or from a developer you haven't used before, your iPhone treats it as untrusted by default. This is a safety feature — it prevents malicious software from running without your knowledge. The app won't open until you tell your iPhone it's safe to use.

The trust process takes about two minutes and involves going into your iPhone's settings to manually approve the developer. Once you do this, the app will open and work normally. You only need to do it once per app.

Key Takeaways

  • Apps from the App Store are automatically trusted, but apps installed through other methods require manual approval in Settings.
  • You must go to Settings > General > VPN & Device Management (or Profiles & Device Management on older iPhones) to find the untrusted app.
  • Tap the developer's name, then tap Trust, then confirm by tapping Trust again in the popup that appears.
  • If you see a message saying the developer is not registered with Apple, the app came from outside official channels and you should verify it came from a source you know before trusting it.

Step-by-step: trusting an app on your iPhone

Step 1: Open Settings. Tap the gray gear icon on your home screen. If you can't find it, swipe down from the top right and search for "Settings".

Step 2: Find the management section. Scroll down and tap General. Then look for VPN & Device Management (on iPhone 15 and newer) or Profiles & Device Management (on older models). If you don't see either option, the app may already be trusted, or it came from the App Store and doesn't need this step.

Step 3: Locate the untrusted app. You'll see a list of apps or developers. Find the one that matches the app you're trying to open. Tap on it.

Step 4: Tap Trust. A button labeled Trust will appear. Tap it once.

Step 5: Confirm in the popup. Your iPhone will ask you to confirm. Tap Trust again in the popup window that appears. This second confirmation is required.

The app is now trusted. Go back to your home screen and open it normally. It should work without any warnings.

Where untrusted apps come from

Apps installed from the official App Store are automatically trusted — you'll never see this message for them. Untrusted app warnings appear when you install software through other routes: a developer's website, a test version sent to you directly, or a file shared through email or messaging apps.

This doesn't mean the app is dangerous. Many legitimate developers distribute test versions this way, and companies often send beta versions to employees or partners. However, it does mean you should only trust apps from sources you recognize. If someone sent you an app and you're not sure who they are or why they sent it, don't trust it.

What to do if you can't find the app in Device Management

If you've looked in VPN & Device Management and the app isn't listed there, the app may have already been trusted, or it may not have triggered the trust warning in the first place. Try opening the app directly from your home screen — it may work without any additional steps.

If the app still won't open and shows an error message, try deleting it and reinstalling it. When you reinstall, the trust prompt should appear again, and you can follow the steps above. To delete an app, press and hold its icon on your home screen, tap Remove App, then tap Remove from Home Screen or Delete App.

Understanding the "not registered with Apple" message

Sometimes instead of a simple trust prompt, you'll see a message saying the developer is "not registered with Apple" or "not verified." This means the app came from outside Apple's official systems entirely — not through a test program or enterprise distribution, but from an independent source.

This isn't automatically a problem, but it does mean you should be more careful. Only trust apps from this category if you're certain about where they came from. If a friend sent you a link to an app and you're not sure what it does or who made it, ask them directly before trusting it.

Trusting apps on different iPhone models

The steps above work on iPhone 15, iPhone 14, iPhone 13, and most newer models. On iPhone 12 and earlier, the menu is called Profiles & Device Management instead of VPN & Device Management, but the process is identical — go to Settings > General > Profiles & Device Management, find the app, and tap Trust.

If you're using an iPhone running iOS 15 or older, the location may be slightly different. Go to Settings > General > Profiles, find the app, and tap Trust. The button and confirmation step remain the same.

Frequently Asked Questions

Do I have to trust every app I install?

No. Apps from the App Store are automatically trusted. You only see the trust prompt for apps installed through other methods — direct downloads, test versions, or files sent to you. Most people never encounter this message.

Is it safe to trust an app?

Trusting an app only means you're telling your iPhone to let it run. It doesn't change how the app behaves or what it can access. If the app itself is malicious, trusting it won't make it more dangerous — but you should only trust apps from sources you know and trust.

What happens if I tap Trust by mistake?

You can untrust an app by going back to Settings > General > VPN & Device Management (or Profiles & Device Management), tapping the app, and tapping the option to remove or untrust it. Then delete the app from your home screen if you don't want it.

Why does my iPhone ask me to trust apps at all?

This is a security feature. It prevents software from running on your phone without your knowledge or consent. By requiring you to manually approve apps from outside the App Store, Apple gives you a chance to verify you actually want to use them.

Can I trust an app and then change my mind?

Yes. Go to Settings > General > VPN & Device Management, tap the app, and select the option to remove it or revoke trust. Then delete the app from your home screen. It will no longer run on your iPhone.