It took a while, but O2 has become the last of the four major UK carriers to launch WiFi and 4G calling on its network. The company confirmed today that iPhone 7 and iPhone 7 Plus owners can now make calls in "notspots" when a wireless connection is available, with other phones coming online "very soon."
The timing of the launch isn't accidental. The introduction of 4G calling, or VoLTE, coincides with Apple's iOS 10.3 update, which began rolling out to UK iPhones on March 27th. VoLTE technology enables clearer calls and improves indoor coverage over 4G networks, enabling customers to seamlessly switch to WiFi when 4G networks suddenly become unavailable.
Before today, O2 offered WiFi calling via its Tu Go app and website, but it wasn't very well publicised. EE and Vodafone have offered WiFi and 4G calling since 2015, while Three only got on board at the beginning of the year.