How to enable VoLTE and WiFi Calling


Just switched from a good old Samsung S7 Edge whose home button broker after 6 years.
Hopefully my FP4 will last longer than that and allow easier repair :slight_smile:

Using Sunrise UPC as Mobile Operator. WiFi Calling and VoLTE was working flawlessly with Samsung S7 Edge stock rom (not operator branded).

Now I am unable to get VoLTE or WiFi Calling working. Config Option is greyed out / not present where Google Searches say it should be. Therefore I’m only getting crappy GSM audio, not HD Audio.

Anyone knows how to get this working?


Sounds like you need to speak to your provider as it maybe be that they don’t support the fairphone for WiFi calling

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Strange, it certainly works as expected for me.
I’m not sure what happens if the device can’t or is currently not booked into a 4G cell. Have you checked if 4G is allowed in your phone configuration? I’m out of ideas otherwise…

Yes it is booked into 4G.

As I work for a telco I was able to contact a colleagues at Sunrise UPC who works in the mobile department and learned that they have tested the Fairphone 4 and found Issues with VoLTE, Wifi Calling and 5G. Therefore they intentionally disable those features when a Fairphone 4 logs into their mobile network.
They are in contact with the manufacturer of the Fairphone 4 to solve those issues but it has no priority as this is not a phone they sell or advertise themselves.

So let’s hope time a update FP4 firmware solves the issue.



Even then, the provider must be willing and able to test it again.

Yes, from the reply I got, they are willing to test, but this device has no priority to them.

That’s what I meant, if Fairphone changes something in the firmware to the better, the provider probably needs weeks or even months to do the new tests.

I am having similar problems in Canada with my new FP4.
I see no option in Networks->Advanced to enable wifi calling.
Presume that is a bad sign.

I plan to add T-Mobile USA over eSIM this week and will try and see if wifi calling appears for that carrier.

No small disappointment but I love the FP4 in every other way.
I will just need to carry a 2nd phone to operate wifi calling when outside North America.

First the option would be under Settings > Network and Internet > then select you network ~ so if you don’t have one you can’t proceed.
If you do click on a network then Advanced > Calling you will see if there is an option. Whether there is or not is down to the individual network, so best ask the ones you may want to use.

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Did you have any luck getting VoLTE on T-Mobile US?

Here are the specifics of my use case.

I both live and work on both sides of the US-Canadian border.
I have two lines of service: T-Mobile US and Freedom Mobile Canada.

I have been successfully using my Fairphone 4 on FM Canada with the exception that FM was unable to provision the handset for both VoLTE and VoWifi.
This line of service is provisioned with a nanoSIM.

The next step was to provision the Fairphone 4 with an eSIM from T-Mobile.
I just spent most of today attempting to do so without success.
I first attempted to scan a QR code from T-Mobile from the network setup screen on the FP4 but the FP4 rejected the scan.

According the the error message on the FP4 as well as the T-Mobile service rep is to manually provision the eSIM on the T-Mobile network using the FP4 EID. Before doing so, the Tmo rep and I thought it best if I first moved my T-Mobile nanoSIM card into the FP4 since the FP4 had never been provisioned with a Tmo nanoSIM.

After installing the Tmo nanoSIM into the FP4, the Tmo data network provisioned the data settings. However, the Tmo service could not successfully provision VoLTE or VoWifi on the FP4. The Tmo rep attempted to provision these features manually without success. Even if the Tmo rep can provision the EID of this handset on the network side, it is unclear to me how to deploy this eSIM on the FP4 manually.

The US location where attempting to do this still has a 3G UMTS carrier and could successfully complete a voice call by dropping down from a 5G or 4G carrier to a 3G connection.

But the biggest surprise of the day is that incoming audio is OK but outgoing audio is not present. No one on the remote end can hear any audio. I called the handset from a different cellphone. Again, on the FP4 incoming audio could be heard but the outbound audio was silent.

Finally, the last problem I experience with this handset is with the USB/C to 3.5mm audio adapter for a wired headset. This, too, failed. I am unable to hear audio with a wired headset.

The disappointments with this handset are growing and beginning to regret buying it.
My last handsets were never sold by my service providers and not directly supported yet all of these features provisioned without a problem.

As for the headset audio problem it appears this product was not completely tested before shipping. I presume a bluetooth headset will work OK.

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Which headsets do you use? Not all work for audio

Reg the microphone issue. Have you called *#*#2886#*#*to check if the microphone n general does not work?
If it generally works it might help to remove permanent access permission of the google app.

Reg the SIM connectivity issues: as the phone is not supported officially in your country its trial and error and also depends on the Region
Please see here


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