With carriers across Europe shutting down their older 3G networks, voice calls now rely on VoLTE (Voice over LTE), also known as 4G Calling. This technology is essential for making calls on the 4G network.

Unfortunately, some network operators only allow VoLTE on a specific list of approved devices. This can sometimes prevent your calls from working correctly, even if your phone is technically capable.

The good news is that by following the steps below, you can help us diagnose exactly what's causing the problem and get the best path to a resolution from your network operator.

Initial checks and diagnostics

Please follow these steps carefully and make a note of the outcome for each test. This information will be vital when you speak to your network operator.

Step 1: Update your software

Make sure that your phone is up-to-date. If you are not running the latest software, or you are not sure, learn how to Check and update your software version.

Step 2: Test data vs. voice (the key VoLTE indicator)

The clearest sign of a VoLTE issue is when your internet (data) works, but voice calls fail.

1. Turn Wi-Fi OFF and check that your device shows the 4G or LTE icon.

2. Test data: Browse a website or stream a short video. Did it work?

3. Test voice call: Attempt to place a phone call (even to an automated service).

Observation: Watch your signal icon during the call. Does it stay on 4G/LTE or does it drop to 'E', 'H', or 'G'?

Note down your findings:

• Did data work while calls failed?

• What happened to the network icon during the call?

Step 3: Check VoLTE status and network mode

Let's check your phone's network settings.

1. Go to Settings ➞ Network and internet ➞ SIMs ➞ Choose your network operator.

2. Confirm Preferred Network Type is set to "4G/LTE/3G Auto" or similar.

3. Look for the "4G Calling" or "VoLTE" toggle.

   • If OFF: Turn it ON and test a call again.

   • If hidden, missing, or greyed out: This usually indicates your operator has not provisioned VoLTE for your device. Please continue to Step 4.

Note down your findings:

• Is the VoLTE toggle visible, and what is its current state (ON/OFF/Hidden)?

Step 4: Verify IMS registration status (the technical check)

This diagnostic code helps us see the device's technical connection status with your carrier.

1. Open the Phone app (dialer).

2. Dial: *#*#4636#*#*

3. If a menu does not appear automatically, look for and click on the three dots menu (top right) and then click IMS service status.

4. Look for "IMS Registration" and "Voice over LTE".

Note down the exact status for:

• IMS Registration: (Registered / Not Registered / Unknown)

• Voice over LTE: (Available / Unavailable)

Carrier compatibility and resolution

Step 5: Check our supported operator list

Your Fairphone is capable of VoLTE and Wi-Fi Calling. We officially support these features with certain network operators.

• Check if your operator is on our supported list: Is my network operator supported?

Step 6: Contact your network operator (essential step)

Whether your operator is supported or not, you must contact them with the diagnostic information you gathered:

"My device is failing to make/receive calls after the 3G shutdown. Diagnostics show: IMS Registration [status from Step 4] and VoLTE Provisioned [status from Step 4]. Can you help provision or troubleshoot VoLTE on my account?"

You can also ask these direct questions:

• Has 3G been shut down in my area?

• Is VoLTE required to make phone calls on your network?

• Do you officially support VoLTE on Fairphone devices?

• Can you re-provision my SIM for VoLTE/IMS services?

Note down your findings:

• What response did you receive from your network operator?

Step 7: Test with a SIM from a supported operator (highly recommended)

If the issue is still not resolved, this test provides definitive proof that your phone's hardware is working correctly.

• If possible, borrow a SIM card from a friend or family member who uses an operator listed on our VoLTE & Wi-Fi compatibility article.

• Insert it into your Fairphone, ensure 4G Calling is enabled, and test a call.

This test confirms whether the issue is with your current operator's policy or your device.

Note down your findings:

• Were you able to test with a supported operator SIM?

• If yes, did calls work with that SIM?

When to Contact Fairphone Support

If you have followed all the steps above, you should have either successfully resolved the issue or received clarification from your network operator.

Please only contact Fairphone Support if all of the following are true:

1. Your Network Operator IS on our  VoLTE & Wi-Fi compatibility list.

2. You have completed Steps 1-6 and have clear answers for all of them.

3. You have already contacted your operator (Step 6), and they confirmed your account and SIM are correctly provisioned for VoLTE, yet calls still do not work.

If you meet all three criteria, please submit a support request and share all the diagnostic information you gathered in Steps 2, 3, 4, and 6.

Resolution for Unsupported Operators

If your phone worked with a supported SIM (Step 7), but calls still fail on your current operator, your phone is working correctly. The issue is due to your current carrier's policy (they have not "whitelisted" your device for VoLTE).

Your options moving forward:

1. Switch to a Supported Operator (Recommended): The most reliable, long-term solution is to switch to one of the operators from our VoLTE & Wi-Fi compatibility list.

2. Continue advocating with your current operator: Ask them to add your Fairphone model to their VoLTE whitelist or manually provision your SIM.