Fairphone 4 - SMS over WLAN connection (when WiFi-calling) - Telefonica o2-Network


based on this issue, that it is impossible to send or receive a SMS when you are only connected to a WiFi-Network (WLAN-Call) in the German o2/Telefonica Network, I want to ask you and the Fairphone-Team for help.

If I use a german Telekom-SIM and WLAN-Call, SMS service works absolutely fine.
But only when using Telefonica /o2, sending and receiving of SMS is impossible.

Is this a o2/Telefonica or Fairphone problem?

If you use VoWifi/WLAN-Call and you have o2-Network/Telefonica in Germany, please test it and write the result here! This would be extremely helpful! To ensure, that it is no individual problem with my configuration.

If you have more informations to the topic, some ideas or any workarounds,… - please do not hesitate to write here :slight_smile:

Thanks a lot and best regards!


Does work with a Vodafone SIM and not with O2 neither on FP4 nor FP5…had to turn on flight mode to “fake” no reception

@yvmuell : Thanks for your reply - this information is very helpful for me!

Best regards!