Call Using Wifi or 4G/5G

WIFI and 4G/5G Calling

o signal? No problem. We’ve introduced two new ways of keeping your business connected if you’re struggling to find a signal.


Whether you’re at home, in a coffee shop or at the office, if you’re having a signal problem, you can use wifi to call as normal. And 4G/5G Calling lets you make calls over 4G/5G, meaning clearer calls.


Wifi and 4G/5G Calling use your minutes and not your data. Your calls are included as part of your usual voice tariff allowance, and out-of-tariff calls are charged at your standard rate.


You’ll move seamlessly and uninterrupted between wifi and 4G/5G network coverage to continue your call, while being able to check your mail or browse the Internet at the same time.

Getting started…
…is easy

If you’ve received a text notification from us, there’s no need to do anything – you’re all set up and ready to go. There’s no need to sign up, register or download a separate app. If you’re connected to a wifi network or you’ve got a 4G/5G signal, you’ll automatically use Wifi and 4G/5G Calling.

New phone?

If you’ve got a brand new phone that’s connected through (see eligable devices below), you will automatically be set up for Wifi and 4G/5G Calling. There’s no need to do anything!

How Do I know I am on Wifi Calling?

The top right of your phone instead of saying O2-UK will say “O2 Wifi Call”.

How is Wifi calling billed?

Wifi calling comes out of your standard UK minutes package – including when you are roaming i.e. a call made when you are on Wifi in France or Canada, will come out of your UK minutes, not as a roaming call.

Does Wifi Calling work with every Wifi network?

No, some networks (specifically those in hotels – for example the Premier Inn – Free Wifi” block the ability to make WIFI calls. Some networks are not of a good enough speed or quality to support Wifi calling and so the device will not support it.

Wifi Assist

Wifi assist is a technology that will check the quality of your WIFI, and if the WIFI network you are connected to is not assessed to be better than the mobile data connection (5G / 4G / 3G etc.) will STILL use your mobile data. This is not affiliated with WiFi Calling and we advise that it should be turned off, as it can lead to unexpectedly large data usage when the customer believes they are on WiFi.


You must have a compatible device to have Wi-fi and 4G/5G Calling enabled, we need to enable your phone to be Wifi and 4G/5G Calling enabled, and your data must be connected to our APN. Visit on your mobile to make sure.

If all the above are true, or Wifi and 4G/5G Calling have stopped working, here are the settings you need to check. Wifi and 4G/5G Calling require two different set ups, so please follow them carefully.

1: Go to Settings and select “Phone”.
2: Tap on “Wi-Fi calling”.
3: Tap on “Wi-Fi Calling on This iPhone”.
4: Read the information and tap on “Enable”.
5: Wi-Fi calling is now active.
1: Go to Settings and select “Mobile Data”
2: Tap on “Mobile Data Options”.
3: Within the options, tap on “Enable 4G/5G”.
4: Select “Voice and Data”. You are now ready to make and receive 4G/5G calls.