Wifi and 4G Calling explained | O2

Wifi and 4G Calling
Another way to stay connected
Make calls with Wifi Calling when you don't have signal. Get clearer calls and better indoor coverage with 4G Calling. Both at no extra charge.
Find out more
How it works
- You’ll be able to start your call over wifi in the office, and as you step outside you’ll seamlessly move onto our 4G network, if it’s available. Check your coverage.
- Once we’ve set you up and you’ve switched it on in your phone’s settings, you’re good to go. No need to sign up, register or download an app.

No extra charges
- You’ll be able to make calls, take calls and send and receive text messages (if you have a supported device that allows for SMS services over WiFi) wherever you have a wifi connection, so you can stay in touch in more places than ever.
- You’ll still be able to use the internet or apps on our 4G network while you’re making a call.

More places to connect
- You’ll be able to make calls, take calls and send and receive text messages (if you have a supported device that allows for SMS services over WiFi) wherever you have a wifi connection, so you can stay in touch in more places than ever.
- You’ll still be able to use the internet or apps on our 4G network while you’re making a call.

Using Wifi and 4G Calling
Wifi and 4G Calling won’t work with some of our other services, including O2 Just Call Me, Mobex or Mobile Recording. You’ll need to remove them to use Wifi and 4G Calling. Don’t worry though – if you change your mind later, you can just switch back through My O2 or your Business Advisor.
More about Wifi and 4G Calling
Coverage and connectivity
- Check your network coverage
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See what O2 network coverage is like where you are.
- More about O2 Wifi
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Free wifi when you're out and about.
- More about 4G
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The things you love, in an instant.
- Help and support
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Your questions answered.
Help and support
- How do I set up Wifi Calling?
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iPhone setup
Go to Settings > Phone > Wi-Fi Calling. Make sure Wi-Fi Calling is set to 'On'.
Can't see these settings on your device? Follow our set-up instructions.
Samsung setup
Go to Settings > Connections > Wi-Fi calling. Make sure Wi-Fi calling is set to On.
To switch off Wifi Calling, set the toggle to Off.Can't see these settings on your device? Follow our set up instructions.
Sony Setup
Go to Settings > More > Wi-Fi calling. Make sure Wi-Fi calling is set to On.
To switch off Wifi Calling, set the toggle to Off.
Can't see these settings on your device? Follow our set up instructions.OnePlus setup
Go to Settings > SIM & network > Enhanced communications. Make sure Wi-Fi calling is set to On.
To switch off Wifi Calling, set the toggle to Off.
Can’t see these settings on your device? Follow our set up instructions.
HTC setup
Go to Settings > Call > tap on Wi-Fi Calling to turn on.
To switch off Wifi Calling, tap to remove the tick.
Can’t see these settings on your device? Follow our set up instructions.Google Setup
Go to Settings > Network & Internet > Mobile network > Advanced > Wi-Fi Calling and turn ‘On’
To switch off Wi-Fi Calling, tap the switch to ‘Off’
Can’t see these settings on your device? Follow our set up instructions.
- How do I set up 4G Calling?
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iPhone setup
Go to Settings > Mobile Data > Mobile Data Options > Enable 4G and then Voice & Data to enable 4G calling.
Can't see these settings on your device? Follow our set-up instructions.
Samsung setup
Go to Settings > Connections > Mobile networks > 4G calling. Set this to ‘On’
To switch off Wifi Calling, set the toggle to Off.
Can't see these settings on your device? Follow our set-up instructions.
Sony
Go to Settings > More > Mobile networks > Enable VoLTE. Make sure Wi-Fi calling is set to On.
To switch off Wifi Calling, set the toggle to Off.
Can't see these settings on your device? Follow our set-up instructions.
OnePlus setup
Go to Settings > SIM & network > Enhanced communications. Make sure Enable VoLTE (4G Calling) is set to On.
To switch off 4G Calling, set the toggle to Off.
Can’t see these settings on your device? Follow our set-up instructions.HTC setup
Go to Settings > Call > tap on 4G Calling to turn on.
To switch off 4G Calling, tap to remove the tick.
Can’t see these settings on your device? Follow our set-up instructions.Google Setup
Go to Settings > Network & Internet > Mobile network > Advanced > Set 4G Calling to ‘On’
To switch off 4G Calling, tap the switch to ‘Off’
Can’t see these settings on your device? Follow our set-up instructions.
- How do I pay for Wifi and 4G Calling?
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It’s no different to a standard call or text message (if you have a supported device that allows for SMS services over WiFi). They will come out of your tariff allowances in the normal way, or they will be charged at the standard tariff rate if you run out.
- Where can I use Wifi Calling?
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Wherever there’s wifi, including anywhere O2 Wifi is available.
- Can I use Wifi and 4G Calling to make calls abroad?
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No, Wifi Calling is not currently supported outside of the UK. However, in certain circumstances it may be possible to enable Wifi Calling whilst abroad and where used additional charges will apply.
You can use O2 Travel to make cheaper calls while you’re abroad. If you’re an O2 Business customer you can use O2 Travel in Europe or our Rest Of World 24 Hour Pass to stay connected while you’re away.