Why your iPhone blocks apps and how to unblock them

When you download an app from outside the App Store or open one that hasn't been used in a while, your iPhone may show a message saying the developer is not trusted. This happens because Apple requires you to manually approve apps before they can run. The process takes about one minute and involves going into your iPhone's settings to tell the system the app is safe to use.

Your iPhone does this to protect you from malware and unwanted software. When you trust an app, you are not saying it is definitely safe — you are telling your phone to stop blocking it. The responsibility for checking whether an app is legitimate falls on you.

Key Takeaways

  • Apps from outside the App Store require manual trust before they will open, which you set up in Settings under General and Device Management.
  • You need the developer's name or certificate information to find the right app to trust, so check your email or the source where you got the app.
  • Trusting an app only affects that one app on your phone — it does not change your security settings for other apps.
  • If you do not recognize the developer name or cannot find where the app came from, do not trust it.

Finding the app in Device Management settings

Open Settings on your iPhone and tap General. Scroll down and look for Device Management or Profiles and Device Management — the exact name depends on your iOS version. Tap it, and you will see a list of developers whose apps you have installed from outside the App Store.

Find the developer name that matches the app you want to trust. If you are not sure which one it is, look at the email confirmation you received when you downloaded the app, or check the source where you got it. The developer name should match what appears in Device Management.

Trusting the developer and allowing the app to run

Tap the developer name in Device Management. You will see a list of apps from that developer. Tap Trust next to the app you want to use. A popup will appear asking you to confirm — tap Trust again.

Your iPhone will now allow that app to open and run. If the app still will not open, try closing it completely and opening it again. If you see a different error message, the problem may be something other than trust — for example, the app may not be compatible with your iOS version.

Removing trust if you change your mind

Go back to Settings, General, and Device Management. Tap the developer name, then tap Untrust or Remove next to the app. Your iPhone will block the app again immediately.

You can also remove the entire developer profile by tapping Delete App or Remove Profile at the bottom of the developer's page. This will untrust all apps from that developer at once and may delete the apps themselves, depending on your iOS version.

What to do if you cannot find the app in Device Management

If the app does not appear in Device Management, it may have come from the App Store instead of outside it. App Store apps do not require manual trust — your iPhone trusts them automatically when you download them.

If you downloaded the app from a website or received it from someone else, it may not have installed properly. Try downloading it again from the original source. If it still does not appear in Device Management after installation, contact the developer or the source where you got the app.

Checking whether an app is actually from who you think it is

Before you trust an app, verify that the developer name matches the person or company you downloaded it from. Scammers sometimes create apps with names that look similar to popular apps but come from different developers.

If you downloaded the app from a company website, go back to that website and check the developer name listed there. If you got it from a person or a link in an email, ask them directly for the developer name before you trust it. If the names do not match, do not trust the app.

Frequently Asked Questions

What happens if I trust an app that turns out to be malicious?

Your iPhone will run the app, and it may access data or settings you have given it permission to use. If you realize an app is harmful, untrust it immediately in Device Management and delete it. Then change any passwords for accounts the app could have accessed.

Do I have to trust every app I download from outside the App Store?

Yes. Any app that did not come from the App Store will be blocked until you trust the developer in Device Management. This is a built-in security step on all iPhones.

Can I trust an app without trusting the entire developer?

No. When you trust a developer in Device Management, you are trusting all apps from that developer on your phone. If you only want to trust one app, you have to trust the developer and then delete the other apps from that developer manually.

Will trusting an app slow down my iPhone?

No. Trusting an app does not affect your phone's speed or performance. It only removes the block that prevents the app from running.

What if my iPhone says the developer certificate has expired?

The developer's certificate — the digital proof that they created the app — has expired. The app will no longer run even if you trust it. Contact the developer to see if they have released an updated version with a new certificate.