Help and support

Wifi and 4G Calling

Wifi and 4G Calling

Want to know if your phone supports Wifi and 4G Calling? Not sure what it is or how it works? What about how to set it up? We’re here to help.

 

See how to set up Wifi and 4G Calling on your phone

Apple set-up
Samsung set-up
Sony set-up
FAQs

Apple Setup

Set up Wifi and 4G Calling for iPhone

How do I set up Wifi and 4G Calling – Apple

First you will have to check that Wifi and 4G Calling has been added to your account. For personal tariff customers – Sign in to My O2Business customers – Contact Business customer services, your Digital Advisor or Business Partner. Once your new services are added to your account, follow the instructions below to enable Wifi and 4G Calling.

 

  1. To enable Wifi Calling, go to Settings > Phone > Wi-Fi Calling. Make sure Wi-Fi Calling is set to On. To switch off Wifi Calling, set the toggle to Off.
  2. To switch on 4G Calling, go to Settings > Mobile Data > Mobile Data Options > Enable 4Gand then Voice & Data to enable 4G Calling. To switch off 4G Calling, select ‘Data’.

 

If you don’t see a Wifi Calling or 4G Calling menu option, you may have to update to the latest iPhone software:

  • Go to Settings > General > Software Update. Install an update if available (you’ll need iOS 10.3 or above)
  • Once installed go to Settings > General > About. The ‘Carrier’ value on this screen should be set to 28.3 or above. If this hasn’t updated automatically, you should get a message from us to update to new carrier settings. Accept by pressing ‘Update’.
  • Follow the instructions above to enable Wifi and 4G Calling

 

Please note: This set-up process may re-start your device so if you would like to receive these instructions by email please click here and we will send them over.

Set up Wifi and 4G calling for Samsung devices

How do I set up Wifi and 4G Calling - Samsung

Firstly you need to add Wifi and 4G Calling to your account. You may have to do this if you purchased your device before 19th May 2017.

  • For personal tariff customers – Sign in to My O2, go to Device Details and tap Wifi and 4G Calling where you can then add the service to your account.
  • Business customers – Contact Business customer services, your Digital Advisor or Business Partner.
  • Once your new services are added to your account, follow the instructions below to enable Wifi and 4G Calling.

 

You can turn on Wifi and 4G Calling in your device settings -

  1. To enable Wifi Calling, 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.
  2. To switch on 4G Calling, go to Settings > Connections > Mobile networks > 4G calling. Make sure Wi-Fi calling is set to On. To switch off 4G Calling, set the toggle to Off.

If you don't see a Wifi Calling or 4G Calling menu option, you may have to update to the latest software:

  • Go to Settings > Software update > Download updates manually.
  • If a new software update is available, select 'Download now'. Once the download completes, your handset will prompt you to install a new version of the software. You can either select 'Install update' or schedule the update overnight.
  • When the install process starts, the device will display the Android installation status bar and then restart. Your screen will show the installation has completed. Select 'OK'. You may need to wait for your device to optimise your existing apps for the new software.

     

    Please note: This set-up process may re-start your device but you can get these instructions by email.

     

How to check if your firmware version is compatible - Samsung

To check if your phone’s running O2 firmware, dial *#1234# on one of the supported devices and look at the CSC entry. If this line includes ‘TEF’, ‘O2U’ or ‘OTF’ then your device has O2 firmware and you can set up Wifi and 4G Calling. If you have a Samsung Galaxy S8 or S8+, the CSC may also include ‘OXM’, in this case you have open market firmware and in this case you can use Wifi and 4G Calling.

If the CSC does not include one of the mentioned codes then Wifi and 4G Calling isn’t supported on your phone right now. If you need more info, get in touch with Business customer services.

How Do I set up Wifi and 4G Calling - Sony

Sony Xperia XZ Premium

Firstly you need to add Wifi and 4G Calling to your account. You may have to do this if you purchased your device before 21st June 2017.

  • For personal tariff customers – Sign in to My O2, go to Device Details and tap Wifi and 4G Calling where you can then add the service to your account.
  • Business customers – Contact Business customer services, your Digital Advisor or Business Partner.
  • Once your new services are added to your account, follow the instructions below to enable Wifi and 4G Calling.

 

You can turn on Wifi and 4G Calling in your device settings -

  1. To enable Wifi Calling, 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.
  2. To switch on 4G Calling, go to Settings > More > Mobile networks > Enable VoLTE. Make sure Wi-Fi calling is set to On. To switch off 4G Calling, set the toggle to Off.

To get Wifi and 4G Calling, your device will need to use O2 firmware*. It should do if you bought it direct from us in an O2 shop, online or over the phone. We’re working to make it available on other Premium phones as soon as we can be sure the experience is great. We’ll get in touch when this happens.

How to check if your firmware version is compatible - Sony

Your device’s firmware is essentially the software that makes it turn on and run. Sometimes there are different versions of firmware for the same device. To check if your Sony is running O2 firmware:

  • Open Settings > Support > Software Information – Tools/Diagnostics
  • Choose the FACTS tab and scroll down to the SOFTWARE section where Customisation is displayed.
  • Check the CDA value. If this doesn’t include the numbers 1308-5293 then we’re sorry, Wifi and 4G Calling isn’t supported on your phone right now. We’re working on it for later in the year and we’ll be in touch when it’s ready. If you need more info, contact us or O2 Business customer services.

*The device firmware is essentially the software that makes your device turn on and run. Sometimes there are different versions of firmware for the same device.

What is Wifi and 4G Calling?

Wifi Calling (also called Voice over Wifi or VoWifi), allows you to make and receive calls even if you can’t connect to the mobile network. When connected to wifi, you can just dial the number you want to call like normal.

4G Calling (also called Voice over LTE or VoLTE) lets you make calls using our fast 4G network, for a clearer voice call. If 4G Calling is available, you can just dial the number you want to call like normal. You can check 4G Calling coverage using our coverage checker.

They’re two great ways to stay connected with O2. Wifi Calling can help when you can’t get a signal, and both give you great quality calls. In 4G Calling areas, they work together to provide a seamless and uninterrupted experience as you move from one to another, without the call dropping.

What phone do I need?

Wifi and 4G Calling is currently available on the following devices:

• iPhone X, iPhone 8 Plus, 8 , 7s Plus, 7s, 7 Plus, 7, 6s Plus, 6s, 6 Plus, 6 and SE

• Samsung Galaxy S8, S8 Plus, Note 8, S7, S7 edge and J3 (2017)

• Sony Xperia XZ Premium, Xperia XZ1, Xperia XZ1 Compact

For Android devices, Wifi and 4G Calling will only work on devices using O2 firmware*. It should do if you bought it direct from us in an O2 shop, online or over the phone.

To check your phone’s running O2 firmware, check the set-up instructions for the Samsung or Sony phones. If you need more info, contact us or O2 Business customer services

*The device firmware is essentially the software the makes your device turn on and run. Sometimes there are different versions of firmware for the same device.

How do I pay for Wifi and 4G Calling?

It’s no different to making a standard call now. It will come out of your call allowance or be charged at the standard tariff rate if you run out.

 

  • No extra charges from O2 – a minute is just a minute no matter how you make the call
  • 4G calls will not cost you any data – clearer calls over 4G and it won’t use your data
  • Wifi calls use very small amounts of data over your wifi connection -
    • If the wifi is unlimited or free (like O2 Wifi) then you won’t be charged anything extra.
    • If your wifi connection has an allowance, then it will come out of that allowance, and your wifi provider may charge if you go over.

 

Multi-Party calls: These are charged as normal but please note that each identical part of a multi-party or conference call will appear on your bill as a separate call entry.

Can I use Wifi and 4G Calling on an O2 sim-only contract?

Yes you can.

  • Using an iPhone X, iPhone 8 Plus, 8, iPhone 7, 7 Plus, 6s, 6s Plus, SE, Galaxy S7, S7 edge, Sony Xperia XZ1, Xperia XZ1 Compact or Xperia XZ Premium with your sim-only contract? To add Wifi and 4G Calling at no extra charge, either go to My O2 and add it to your account, or contact us.
    Please note, Wifi and 4G Calling is only available on Samsung and Sony devices bought directly from O2 customer services, O2 shops or O2 online.
  • Transferring your personal tariff to a sim-only contract and want to add Wifi and 4G Calling? Either go to My O2 to add it to your account at no extra charge, or contact us.
  • Have an O2 Business sim-only contract and want to add Wifi and 4G Calling? Get in touch with your Account Manager, Digital advisor, Business Partner or contact Business customer services to add it to your account at no extra charge.
Will my phone automatically use Wifi or 4G Calling?

When you have wifi coverage but can’t connect to the mobile network, your phone will automatically use Wifi Calling.

Apple devices
The carrier message at the top of your screen will change to ‘O2 WifiCall’. If you have a strong phone signal, your phone will automatically use 4G Calling and your bearer will show as ‘4G’.

Samsung and Sony devices
The indicator bar will display a wifi/phone icon. If you have a strong signal, your phone will automatically use 4G Calling and your bearer will show as ‘4G’.

Calls made over wifi will only drop if you move out of range and 4G Calling isn't activated or available. If you’re in an area where both Wifi and 4G Calling are available, the call will use 4G first.

You can check 4G Calling coverage using our coverage checker.

Where can I use Wifi Calling?

You can use Wifi Calling wherever there is wifi, including wherever O2 Wifi is available. It’s free to connect to O2 Wifi, but remember other wifi providers might charge you to connect, like on certain trains and in some hotels.

Can I use Wifi and 4G Calling to make calls abroad?

You can’t use Wifi and 4G Calling when you’re abroad. Wifi calls won’t work. Mobile calls will use 2G/3G Roaming and you’ll be charged according to your normal tariff.

Personal tariff customers – Use O2 Travel to stay connected when you’re abroad.
Business customers – Use O2 Travel for Europe or our Rest Of World 24 Hour Pass to stay connected while you’re away.

Can I use Wifi and 4G Calling on an O2 Business tariff?

Yes, but at launch Wifi and 4G Calling isn’t available on the O2 Business Mobex or the Best for Business tariffs.

Can I use other O2 services with Wifi and 4G Calling?

At this stage TU Go is not compatible with Wifi and 4G Calling. To switch between TU Go and Wifi and 4G Calling:

  • Personal tariff customers – Sign in to My O2 change services between TU Go and Wifi and 4G Calling.
  • Business customers – Contact Business customer services. your Digital Advisor or Business Partner if you need help with moving from TU Go to Wifi and 4G Calling.

     

    Voicemail and texts when using Wifi Calling without mobile coverage:

    • SMS, MMS and Visual Voicemail (VVM) messages need mobile coverage to reach your phone so these won’t work in wifi-only areas.
    • You’ll still be able to receive voicemails but, as above, text notifications will only work if you have mobile coverage so you’ll need to dial 901 to check for new messages.
    • iPhone customers – iMessage will continue to work even if you only have wifi coverage available.

    Note: If you need to receive texts, you can switch off Wifi Calling through your device settings.

Is there anything else I need to know?

You can still use Wifi Calling to make calls to the emergency services. Please note that if you dial 999 using Wifi Calling where there’s no mobile coverage, the operator will need to ask where you’re calling from as wifi calls don’t show location information.

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