4G Calling (aka 4G Super-Voice or VoLTE) gives you higher-quality phone calls and better indoor phone call coverage.

When 4G technology was first launched in the UK, it was designed only to carry mobile data. So whilst you could use a 4G connection to browse the web with super-fast download speeds, you couldn’t make regular mobile phone calls on a 4G connection. Because of this, most 4G mobile phones today will still fall back to either a 2G or 3G connection when you make or receive a call.

4G Calling (also known in the UK as 4G Super-Voice or VoLTE) is a new technology that allows you to make and receive phone calls over a 4G connection. It means your mobile phone is no longer required to fallback to either 2G or 3G every time you need to make or receive a call. This gives you a more reliable phone call experience, along with other benefits such as higher-quality HD Voice phone calls, better indoor coverage with lower-frequency spectrum, and faster download speeds whilst you’re on a call.

In this article, we’ll tell you everything you need to know about 4G Calling in the UK. We’ll discuss how the service works and how you’re able to use it on different UK mobile networks. We’ll also discuss the limitations of the technology and possible alternative solutions.

What is 4G Calling?

4G Calling (also known in the UK as 4G Super-Voice or VoLTE) is a new technology that allows you to make and receive phone calls whilst connected to a 4G network. It replaces the older CSFB technology, where your phone will fall back to either a 2G or 3G connection whenever you want to make or receive a phone call.

The benefits of 4G Calling are as follows:

  • More reliable phone calls. Traditionally, 4G mobile networks have made use of CSFB technology (circuit-switched fall-back technology). With CSFB, your mobile phone will switch back to either a 2G or 3G connection when you make a call. This switch-over doesn’t always happen successfully, leading to occasional call failures. With 4G Calling, this switch-over is no longer necessary so phone calls should work more reliably and should come through more quickly.
  • Better indoor coverage with lower-frequency spectrum. The UK mobile networks have been rolling out 4G technology at lower-frequency 800MHz spectrum. Compared to the 3G networks which have traditionally used 2100MHz, this lower-frequency spectrum travels much further indoors. As a result, you should get better quality indoor coverage for your phone calls.
  • Faster download speeds whilst connected to 4G. As your phone no longer needs to fall back to the slower 2G or 3G network whilst you’re making a phone call, you’ll be able to stay on 4G which means you’ll have the fastest download speeds even whilst on a call.
  • Seamless ability to continue Wi-Fi Calling phone calls. If you’re using Wi-Fi Calling functionality, your phone calls will be able to continue on 4G Calling when you leave the range of the wi-fi network.

4G Calling: By Network

4G Calling is currently available to customers on BT Mobile, EE, iD Mobile, O2, Three and Vodafone. You’ll need to have a compatible price plan and handset to use with 4G Calling.

BT Mobile

You can use 4G Calling on any type of BT Mobile price plan, including Pay Monthly contracts, SIM Only and Family SIM. However, the service only works on the iPhone 6 and newer, plus selected Android smartphones purchased directly from BT Mobile:

4G Calling works with any iPhone 6, iPhone SE, iPhone 7, iPhone 8, and iPhone X, as long as you have a mobile plan with us.

4G Calling also works with the Samsung Galaxy S9 and S9+, as long as they were bought from us and you have a mobile plan with us too.

You can see a full list of compatible handsets and plans on the BT Mobile website.

Source: BT Mobile: About Wi-Fi Calling
Tariff Information: BT Mobile Website


On EE, it’s possible to use 4G Calling on any Pay Monthly plan, providing you’re in an area that’s covered and providing you have one of the following compatible smartphones:

  • an EE pay monthly plan on one of these phones bought from any retailer:
    • Apple iPhone 6, 6 Plus, 6S, 6S Plus, SE, 7, 7 Plus, 8, 8 Plus, X
    • Google Pixel, Pixel XL, Pixel 2, Pixel 2 XL
    • Sony Xperia XZ1, Xperia XZ1 Compact
    • Huawei P10, P10 lite, P10 Plus, P Smart
    • HTC U11, U11 Life
    • Blackberry Priv, Dtek 50, Dtek 60, KEYone
    • Nokia 3, 5, 8
    • EE Hawk
  • or one of these phones, bought directly from EE:
    • Samsung Galaxy S9, S9+, S8, S8+, S7, S7 edge, S6, S6 edge, S6 edge+, Xcover 4, A3 (2017), A5 (2017), J5 (2017), Note 8
    • Sony Xperia L1, XA1, XZ, XZ Premium, X, XA, X Compact, Z5, Z5 Premium and Z5 Compact
    • Microsoft Lumia 550, 650, 950, 950XL
    • Huawei P8 lite (2017), P9
    • HTC 10
    • LG G6, G5, G5 SE, X Cam, K8 (2016), K8 (2017), K10 (2017)

Source: EE Help: How do I use 4G Calling?
Tariff Information: EE Website

iD Mobile

On iD Mobile, access to 4G Calling is available on all Pay Monthly price plans, providing you’re in an area that’s covered by the service. At the time of writing, the following handsets are supported by iD Mobile:

iPhone 5s, iPhone SE, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone 7, iPhone 7 Plus, iPhone 8, iPhone Plus, iPhone X, Huawei Mate 10 Pro, Huawei P-Smart, Huawei Mate 20 Lite, Huawei P20, Huawei P20 Plus, Huawei P20 Lite, Huawei Y7, Huawei Honor 9 Lite, Honor Play, Honor View 10, Samsung A6 2018, Samsung J6 (2018), Samsung S8, Samsung S8+, Samsung S9, Samsung S9+, Samsung Galaxy Note 8, Samsung Galaxy Note 9

Source: iD Mobile Help: 4G Calling
Tariff Information: iD Mobile Website


On O2, you’ll have access to 4G Calling on Pay Monthly and SIM Only contracts, providing you have one of the following compatible devices:

  • iPhone Xs, iPhone Xs Max, iPhone X, iPhone 8 Plus, 8, 7 Plus, 7, 6s Plus, 6s, 6 Plus, 6, SE
  • Samsung Galaxy S9, S9 Plus, S8, S8 Plus, Note8, S7, S7 edge and J3 2017, A8, A3 2017, A6, J6, J5 (2017), A5 (2017), Note9
  • Sony Xperia XZ2, XZ2 Compact, XZ Premium, Xperia XA2, Xperia XZ1, Xperia XZ1 Compact
  • Oneplus 5, 5T, 6
  • HTC U11

If you have an Android-based smartphone, your device will typically need to be running on O2-provided firmware. In most cases, this means your handset will need to have been purchased directly from O2. However, it will also work on certain handsets purchased from a third-party provider.

Source: O2 Help & Support: Personal Hotspot
Tariff Information: O2 Website


Three refers their 4G Calling service as 4G Super-Voice. This refers to the fact that their 4G Calling service uses lower-frequency 800MHz spectrum to break indoors (previously used by the broadcast television channels before the digital switchover). With the signal travelling further indoors, you should benefit from wider calling & texting coverage, along with higher-quality phone calls.

At the time of writing, Three’s 4G Super-Voice is available on the iPhone 6 and newer (purchased anywhere) and on selected Android smartphones that have been purchased from Three:

  • Apple: iPhone X, iPhone 8 Plus, iPhone 8, iPhone 7, iPhone 7 Plus, iPhone 6, iPhone 6 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE
  • Huawei: Huawei Honor 6X, Huawei Honor 9, Huawei P10, Huawei P10 Plus, Huawei P9, Huawei Mate 9, Huawei Mate 10 Pro
  • LG: LG G6, LG G5, LG G4 Compact, LG G4, LG Spirit 4G, LG Stylus 3, K3
  • HTC: HTC 10
  • Lenovo: Lenovo P2
  • Razer: Razer Phone
  • Microsoft: Nokia Lumia 550
  • Motorola: Moto G 4G 3rd Gen, Moto E4 Plus
  • Samsung: Samsung Galaxy Note 8, Samsung Galaxy S8 Plus, Samsung Galaxy S8, Samsung Galaxy S7, Samsung Galaxy S7 Edge, Samsung Galaxy S6, Samsung Galaxy S6 Edge, Samsung Galaxy S6 Edge Plus, Samsung S5 Neo, Samsung Galaxy S5, Samsung Galaxy A5 2017, Samsung Galaxy J3 2016, Samsung J3 2017, Samsung Galaxy A3 2017, Samsung Galaxy A3 2016, Samsung Galaxy Note 4
  • Sony: Sony Xperia Z5, Sony Xperia Z5 Compact, Sony Xperia X, Sony Xperia XA, Sony Xperia XZ Premium, Sony Xperia XZ
  • ZTE: ZTE Blade V7, ZTE Blade V8

Source: Three Network: 4G Super-Voice
Tariff Information: Three Website


Vodafone offers 4G Calling to Pay Monthly customers with either a Red, Red Extra, Red Entertainment or Red Value plan. It’s also available to most Vodafone Business customers.

To use 4G Calling, you’ll need a compatible handset as listed on the Vodafone website:

  • Apple (iOS 11.3 and above only): iPhone X, iPhone 8, iPhone 8 Plus, iPhone 7, iPhone 7 Plus, iPhone 6s, iPhone 6s Plus, iPhone SE
  • Huawei: P10, P10+, Mate 10 Pro, P Smart, P20, P20 Lite, P20 Pro
  • Samsung: Note 8, S9 Plus, S9, S8 Plus, S8, S7 Edge, S7
  • Sony: XA2, XZ, XZ Premium, XZ1, XZ1 Compact, XZ2
  • Vodafone: Smart N8

All Android devices will need to have been purchased directly from Vodafone to be compatible with 4G Calling.

Source: Vodafone: Network Calling Features
Tariff Information: Vodafone Website

Unfortunately, 4G Calling isn’t yet available on other mobile networks like giffgaff, Plusnet Mobile, Sky Mobile, Tesco Mobile and Virgin Mobile.

How To Enable 4G Calling On Your Phone

Once you have a compatible price plan and handset, you’ll also need to switch on the 4G Calling functionality on your smartphone before you can use it.

If you’re using an iPhone, you can switch on the 4G Calling feature by going to Settings > Cellular > Cellular Data Options > Enable LTE. Select the option to use LTE for both ‘Voice & Data’.

On Android devices, the exact location of this setting will vary. However, you’ll often be able to find it through Settings > Connections > Mobile networks > 4G calling or Settings > More > Mobile networks > Enable VoLTE.

Drawbacks & Limitations

4G Calling only works when you’re in the UK.

4G Calling is a fantastic feature, and a good addition to being able to make phone calls on 2G and 3G. However, there are also some major drawbacks and limitations of the service at present:

  • 4G Calling only works on a limited number of handsets. At present, handset compatibility for 4G Calling is patchy. This is especially the case if you’re using an Android device, which will normally need to have been purchased directly from your mobile network. This requirement means that 4G Calling often won’t work on unlocked smartphones, and on devices purchased from third-party retailers like the Carphone Warehouse.
  • Network settings may be set up to prefer 3G Calling. Typically, it isn’t possible to “force” your handset to use 4G Calling. In some cases, the network settings may be set up in such a way to prefer 3G over 4G.
  • 4G Calling only works in the UK. If you’re travelling abroad, it won’t typically be possible to use 4G Calling.

Using voice-over-IP applications such as WhatsApp and Skype can be an alternative to 4G Calling. You can use these applications to make a phone call whilst you’re connected to 4G but it won’t use your regular phone number or price plan. In cases where you’re doing something like calling abroad, this may sometimes work in your favour as it may be cheaper to use one of these services.

More Information

For more information about 4G Calling, please see the BT Mobile, EE, iD Mobile, O2, Three and Vodafone websites.

Your Comments 20 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 20 comments from readers. You can add your own comment here.

  • A bit late to this discussion point, but my question follows on from earlier posts about 3 mobile’s 4G and 4G super-voice calls. If the ‘VoLTE’ symbol appears on the phone screen, is this definitive proof that the phone is indeed delivering VoLTE calling?

    I ask this because I use an inexpensive Cubot P40 with a 3 payg sim. On the face of it an unsupported phone, not supplied by 3 and used on payg should not be able to use 3’s VoLTE – but the symbol is ever-present on the phone screen

    • Hi Ken,
      Thanks for your comment. I guess the definitive way to check would be to make or receive a phone call when you’re connected to 4G. I’d also make sure Wi-Fi is switched off just to be sure you’re not using Wi-Fi Calling. If your phone doesn’t switch to 3G coverage, then it’s most definitely using 4G Calling (VoLTE). If it isn’t, a technology called CSFB will kick in (Circuit Switched Fallback), making your phone switch back to 3G whenever you make or receive a call.
      Hope this helps,

      • The VoLTE symbol does indeed remain on the screen during calls. Looks like VoLTE will actually work on a wider variety of phones than 3 mobile have indicated!

  • I’ve noticed that Three’s Super-Voice doesn’t work all the time because it’s limited to LTE Band 20 (800 MHz). E.g. my local mast broadcasts on Band 3 (1800 MHz) so my phone locks on to that but there’s no VoLTE.

    • Hi Kurt,

      Assuming that your phone is VOLTE capable and you’re in a 4G supervoice area (you can check on the 3 website coverage checker here: http://www.three.co.uk/Discover/Network/Coverage) then the following needs to be borne in mind.

      1. If there is a usable 3G signal which the three network uses for voice calls , then VOLTE isn’t needed. The 3G / H / H+ icon doesn’t need to be shown on the handset for this to work, mine usually shows 4G but when I make a call the 3G / H / H+ icons display. This implies that 4G coverage overlays 3G coverage.

      2. The VOLTE (Supervoice) will only kick-in if the 3G signal is to weak to handle a call typically in a rural area or in a building if the 3G signal becomes to weak. This is technically known as Circuit Switched Fallback (http://www.telecomabc.com/c/csfb.html)

      3. You can verify this by using a network monitoring app like Network Cell Info which will list the base station you’re connected to along with other ones that the mobile knows about but isn’t using. On my phone the Supervoice frequency of 800Mhz is generally shown at the bottom of the list.

      4 The aim is to eventually carry calls naively over 4G on the higher frequency bands too. When this happens, I’m guessing that the only way we’ll know is if the 3G / H / H+ symbol doesn’t appear when a voice call

      • Thanks for the update Martyn!

        I have a cheap Chinese phone with a Mediatek processor. I was able to use the ‘MTK Engineering Mode’ tool from the Google Play Store to temporarily disable the LTE Band. My phone then picks up a more distant cell site which, presumably, in on Band 20 because then ‘VoLTE’ is shown on my display. Anyway, thanks again for the useful info and links.

  • I’ve just purchased a Moto G7 SIM Free (UK Version) which was not sourced from the Three network. I have two SIM’s in the phone: 1 x Pay As You Go and 1 x Rolling monthly contract. (Both on the 3 network)

    I am happy and somewhat surprised to report that the voLTE appears to be enabled when another icon appeared on the right hand side of the notification bar with a small handset which initially confused me today as I had no active call when I was in central Nottingham. I figured that it may be voLTE.

    To test this, I make a voice call from one of my favorite coffee shops where there was previously no signal at all and the call worked fine. It even appeared to remain enabled when I subsequently connected to the local WiFi network.

    It was also clear from the dual SIM network signal strength notification bars (One for each SIM) that the Pay As You Go SIM had completely lost its 4G network connection which is what I would expect given that voLTE had not been enabled on that SIM card (controllable by myself through the phones settings)

    It’s also interesting to note that a 4G+ symbol (It normally just shows 4G) also appeared when I was watching Netflix via a tethered connection at home earlier in the day which apparently boosts 4G speeds by up to 33% through carrier aggregation.

    See: https://www.computerweekly.com/news/252451804/Three-introduces-4G-at-2700-sites

    So overall, it appears that 3 are now managing to enable voLTE and 4G+ on certain non 3 sourced mobiles which I believe is their aim anyway. It should be noted that both functions appear to be dynamic in that they are only activated as required i.e A weaker voice call signal area triggers voLTE and/or high data demand may trigger 4G+ if required.

  • Hi Ken,

    There’s a lot of information out there and for a non techi person like me it’s all quite confusing so your advise would be appreciated.

    We live in a black spot area which doesn’t appear to receive a signal from any provider. Until now I have been relying on WhatsApp for voice calls but that is unreliable and keeps dropping the call. However Three claims on their website that although we don’t have 4G we can get 4G Super Voice calling – hows that then? How can you have one without the other? That’s confusing from the start.

    Before I read about Three’s Super Voice calling we were investigating Wi-Fi calling which I believe runs differently to Whats App and would be more reliable?

    Should I choose Three’s Super Voice (if it really is available to us) over another provider which only offers WiFi calling? We thought it would be better to choose Three as I understand it offers both and therefore would be more of a belt and braces job?

    Many thanks.

    • Hi Casa,
      Thanks for your comment. You’re right – this is really strange. In the technical sense, it’s absolutely true that you can’t have 4G Calling or 4G Super-Voice with no 4G coverage (as it’s the underlying 4G coverage that carries the phone call). In this case, however, I don’t know how Three are advertising the services on their website. I believe they use 800MHz spectrum for 4G Super Voice, as opposed to their usual 1800MHz spectrum for normal 4G. It’s possible they’re saying that you should be able to get the 800MHz 4G service, but not the 1800MHz service. This is probably something I would clarify directly with Three and I would love to find out what they say on this!

    • Martyn replied:

      The first thing to do Ken, is to check if Three super-voice is available in the area(s) you wish to use your mobile in. That can easily be done at the following web address:


      If available, the next thing to do is to verify that the mobile you’re using will support Super-voice (voLTE). You can check whether a particular device is supported at the web address given above too.

      Generally, Three state that they only provide voLTE and Voice over WiFi (voWifi) for mobiles sourced from them since it requires specific software that Three provide themselves for their own mobiles.

      That said, they also state that they hope to expand support to mobiles not sourced from Three. As per my earlier post in this forum, it appears that the (UK Model) Moto G7 purchased SIM free from Amazon does support both voLTE and voWiFi. Both features have to be enabled within the phone’s settings and I can confirm that both are working for me on a Three pay monthly SIM.

      I’m guessing that the complete Moto G7 series e.g. Moto G7 Plus / Mpto G7 Power will also provide similar functionality but I’d await verification from someone who actually owns these phones to prove the point.

    • Hi Casa,

      Yes, this is very confusing indeed! I’ve been researching this because Super-Voice isn’t working in my area even though Three says it’s available. The reason for this is that Three only broadcast the service on their lower frequency Band 20 (800 MHz). Thanks to Ken for confirming this BTW. The mast near to my house must be Band 3 (1800 MHz) only. Therefore, if Three are telling you that you can receive Super-Voice in your area then, yes, it will only be Band 20 (800Mhz). There are apps available which you can check what band your phone is on (e.g. Signal Spy for Android, not sure about iPhone).

      So to answer your question, you should be able to get 4G if Three say that Super-Voice works in your area. Their website is confusing because I’ve noticed as well that they say there are areas with “No 4G but Super-Voice”. This is misleading to customers – as Ken has already mentioned you can’t have Super-Voice without it being 4G! Three’s coverage map may show no 4G in your area but if you check the Super-Voice option it will probably say that it works. However, I would obtain (or borrow) a free SIM card from Three to test this out – don’t take their word for it.

      Hope this helps.

      Kind regards,


      • Kurt Hitchen replied:

        Hi all,

        Just an update for you. I visited the Lake District this week (postcode: LA8 9PY). On checking the iD mobile coverage map, it reports NO 4G COVERAGE AT THIS POSTCODE! However, if you then tick the option “I have a 4G Voice Calling compatible phone, show me my updated coverage map”, it then shows excellent 4G coverage. I can confirm that this is true – the 4G coverage is being provided on Band 20 (with VoLTE).

        Strangely though, iD/Three seem not to be wanting to advertise this fact. From my experience, the phone rarely automatically connected to the 4G network but remained on 3G which is disappointing. I did manually force the phone on to LTE mode and unsurprisingly, I received good 4G VoLTE coverage, but soon as I switched the phone to LTE/UMTS/GSM the phone dropped back to 3G. I thought that this could be a fault with the phone, so I tried another 4G phone and that also remained on 3G/UMTS.

        I’m rarely getting 4G with VoLTE anywhere, so I’m not sure what Three are playing at. It almost feels like they don’t want people to use Band 20 because they don’t have as much spectrum available on that band? Thoughts please…?

        • Hi Kurt,
          I’m really sorry for the delay in responding to your comment over the Bank Holiday weekend.
          You make a really good observation regarding 4G coverage on Three. Essentially, mobile networks can decide to set their own priority of when different types of coverage are used. This determines which type of coverage your phone uses at different times. Three’s current configuration is to prioritise 3G coverage @ 2100MHz over 4G coverage @ 800MHz. This is why your mobile phone is connecting to a weak 3G signal, rather than the stronger & faster 4G Super-Voice signal. I believe Three are often criticised in online forums for this behaviour (e.g. see here). I believe the only work around is to set your phone to 4G only like you say, but this isn’t ideal as soon as you lose 4G coverage…

          • Kurt Hitchen replied:

            Thanks Ken, much appreciated. I have also heard rumours that Three will launch Supervoice / 4G calling on 2100 MHz so we’ll have to wait and see.

            Best wishes,


  • Brian Shanahan-Gray said:

    Hi Ken, I’ve got a Samsung note 9 that I bought from Argos in December. It is running Android Pie. I live in a rural area and signal is patchy. A friend told me I should be able to use 4g calling & WiFi calling with Three or ID mobile even though I didn’t buy my handset from either of them directly. Is this now possible as I remember Three used to insist that your phone ran their firmware to access 4g calling?


    • Hi Brian,
      Thanks for your comment. As a rule of thumb, I definitely wouldn’t rely on this behaviour when using an Android smartphone purchased from somewhere other than the mobile network. You’re right that there’s work being done to enable to this for unlocked handsets, but unfortunately I’m not sure what the latest status of that currently is, and I’m not sure the mobile networks maintain a list for this either (your mileage is likely to vary depending on your handset, mobile network, etc).

  • Hi Ken, in your excellent article on 4g calling in the section related to O2 (my current provider) you state: ‘On O2, you’ll have access to Wi-Fi Calling on Pay Monthly and SIM Only‘
    So, is there 4g calling on O2? I was under the impression that Wi-fi calling and 4g calling are not the same thing. The alternative for me is Three where you clearly state in your article that 4g calling is available via their “4g super voice” system. Before I ditch o2 can you just confirm that they do or do not support 4g calling but that the section in your article mentioning Wi-fi calling should be amended to state 4g calling?
    Many thanks.

    • Hi Rick,
      Whoops! Looks like a typo in my article – it should read “4G Calling” and not “Wi-Fi Calling”. Thanks for letting me know – I’ll amend this above 🙂

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