Voice over IP (VoIP) calls allow users to make audio or video calls over the internet using apps like WhatsApp, FaceTime, Skype, or Zoom. However, if you’re experiencing VoIP call failures on your iPhone, it can be frustrating — especially when you’re relying on these calls for work or personal communication.
In this article, we’ll explore the most common reasons why VoIP calls may fail on your iPhone and how to resolve the issue quickly.
Common Causes of VoIP Call Failures on iPhone
- Weak or Unstable Internet Connection
- App Permissions or Restrictions.
- Battery Saver or Low Power Mode
- VPN or Network Configuration Issues
- Outdated App or iOS Version
- Do Not Disturb or Focus Mode
How to Fix VoIP Call Failures on iPhone
Solution 1. Check Internet Connection
Switch between Wi-Fi and Cellular to see which works better. Restart your router or move closer to it for a stronger signal.
Solution 2. Restart Your iPhone
A simple restart can resolve temporary software glitches affecting VoIP calls.
- Press and hold the Side button and either Volume button until the power slider appears.
- Drag the slider to turn off the iPhone.
- Wait a few seconds.
- Press and hold the Side button again until you see the Apple logo.
Solution 3. Update the App and iOS
Go to the App Store and update the VoIP app—for example, WhatsApp, FaceTime, Skype, Zoom, Viber, Telegram, and Google Voice.
Navigate to Settings App > Tap on General > Click on Software Update to check for iOS updates.
If you have any pending updates available, we highly recommend taking a moment to update your device. Keeping it up to date ensures you have the best performance and access to the latest features.
Solution 4. Check App Permissions
Checking app permissions means reviewing which features an app is allowed to use — and making sure it has access to the things it needs to work properly. For instance, camera, microphone, location etc.
Go to Settings > Privacy & Security > Microphone and ensure the app is allowed.
Also, check Settings > Cellular to confirm the app is permitted to use mobile data.
Solution 5. Disable Low Power Mode Temporarily
Go to Settings > Battery and turn off Low Power Mode.
Solution 6. Turn Off VPN (if enabled)
Go to Settings > VPN and disconnect any active VPN connections, then try the call again.
Solution 7. Disable Do Not Disturb / Focus Modes
Swipe down to open Control Center and turn off any active Focus or Do Not Disturb settings.
Solution 8. Reinstall the VoIP App
Delete and reinstall the app to ensure a clean installation and refreshed configuration.
If you’re still experiencing issues, try contacting the app’s support team or Apple Support for assistance. In rare cases, it may be a carrier-related issue or a more complex network configuration problem.
