Fixing “Unable to Install App” on iPhone

You tapped an install link, the icon appeared… then “Unable to Install”. This error has a small set of real causes — here they all are, most common first.

1. Your UDID isn't in the provisioning profile

For ad-hoc builds, Apple checks your device's UDID against the list embedded in the app. Not on the list → refusal. Fix: send the developer your UDID (find it with our free tool) and ask for a re-signed build.

2. Expired or revoked certificate

Signing certificates expire yearly and can be revoked. Fix: developer re-signs with a valid certificate.

3. The link wasn't served over HTTPS

iOS silently requires HTTPS for OTA installs. Links from IPALinked are always HTTPS.

4. Not enough storage

Check Settings → General → iPhone Storage.

5. iOS version below the app's minimum

The build's minimum iOS version is higher than the device's. Fix: update iOS or lower the deployment target.

6. Enterprise app not trusted yet

For enterprise builds: Settings → General → VPN & Device Management → trust the developer.