Using your non-UK cellphone/mobile phone in the UK

March 20th, 2010

La farola - The streetlight
Creative Commons License photo: Rob Unreall

A guide for visitors to the UK.

Whether you’re visiting Britain on holiday and hoping to take advantage of the fantastic exchange rates or visiting Britain for a longer amount of time, you may be wondering whether it is possible to use your phone in the UK. This guide aims to answer some of your questions.

What technologies do UK mobile networks use? GSM or CDMA?

Globally, there are two main technologies for mobile networks – GSM (Global System for Mobile communications), which is used in 80% of the countries across the world, and CDMA (Code Division Multiple Access) which is popular in North America and some countries in Asia.

In the UK, all of our mobile networks use GSM. Within GSM, there are several standards. These are GSM900 (GSM at a frequency of 900MHz), GSM1800 (GSM at a frequency of 1800MHz) and 3G 2100 (3G at a frequency of 2100MHz). Your phone will need to support one of these.

We have five primary networks which support the following technologies:

  • 3: 3G 2100
  • Orange: GSM 1800, 3G 2100
  • O2: GSM 900/1800, 3G 2100
  • T-Mobile: GSM 1800, 3G 2100
  • Vodafone: GSM 900/1800, 3G 2100

London Eye
Creative Commons License photo: johannes pape

If the network you are considering is not on this list, it is a mobile virtual network operator (MVNO) meaning that it leases network capacity from one of the above networks. For example, Giffgaff is a MVNO on O2. This means it supports the same technologies as O2: GSM 900/1800 and 3G 2100.

How can I tell whether my phone is GSM or CDMA?

The first step to finding out if you can use your phone in the UK is  to determine whether your phone is a GSM phone. If your country and network is listed on the GSM coverage listing, the chances are you will have a GSM phone.

For visitors from the US:

  • Cingular, AT&T and T-Mobile are GSM networks so phones from these networks should work in the UK
  • Sprint PCS, Verizon and Virgin Mobile are CDMA networks so phones from these networks probably won’t work in the UK

Dual-band GSM phones will support both GSM900 and GSM1800.

What packages can I use?

From this point onwards, we assume you have a GSM phone which will work in the UK.

The easiest but most expensive solution is to roam on your home network. Typically, you don’t have to do anything to roam – just take your phone abroad and it’ll still work (providing your network has a roaming agreement with a UK network). Roaming typically costs a lot so I recommend that if you want to stay for more than a few days then you should get a SIM card from a UK network.

To use a UK SIM card within your existing GSM phone, you will need an unlocked mobile phone. If you are staying for less than a month, your best bet would probably be to go with a Pay As You Go package. If you’re staying for longer, you could look into SIM only contract. You’ll probably find it difficult to obtain one unless you have a UK bank account and address though.

How can I obtain a Pay As You Go SIM card?

Piccadilly Circus
Creative Commons License photo: Spoungeworthy Redux

PAYG SIM cards are very easy to obtain – you do not need to provide an address or any credit card details.

They are typically free in the UK when you request one online. This will include a UK telephone number (it will begin with 07). These SIM cards will give you cheap calls and texts within the UK (calls from 8p/minute and texts from 4p each). Be careful though – some networks charge up to £1.50/minute for international calls.

If you’re looking to call home, the O2 Your Country SIM card is worth considering. It gives you 100 free minutes of international calls when you top up £15 and international texts cost just 10p (and it is free to receive texts too!).

You could also look into specialist international call providers. Networks such as LycaMobile and Lebara Mobile will allow you to call home from 4p/minute.

If you don’t have a UK address where a PAYG SIM card can be delivered to, you can keep your eyes open for PAYG SIM cards being offered in shops. You might find them at the airport, your hotel, places such as Chinatown or mobile phone shops on the local high street. You’ll normally have to pay for a SIM card if you buy them from a shop – and double-check what the cost of calls is.

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About Ken

Ken Lo

I'm a freelance writer specialising in mobile technology. I've been blogging at Ken's Tech Tips since 2005 with the aim of demystifying mobile technology for the rest of us.

Before writing about mobile technology, my background was in space & atmospheric physics. I have also worked in software development. Nowadays, I help companies to explain mobile technology to their customers. Please check out my portfolio or get in touch for more information. I'm also on Google+.

Your Comments

We'd love to hear your thoughts and any questions you may have. So far, we've received 70 comments from readers. You can add your own comment here.

  1. sue said:

    I have just purchased an iFcane E1 mobile, it will not receive or make calls have tried 3 sim cards none work. What could be the problem?

    1. Ken Lo
      Ken replied:

      Hi Sue,
      Thanks for your comment. I’ve just done a quick search on Google: it looks like the iFcane E1 is a 2G-only handset. Unfortunately, you must have a 3G or 4G handset before you’re able to use the Three network. The good news is it apparently supports GSM 850/900/1800/1900MHz. You should, therefore, be able to use it on other networks in the UK (e.g. you could try a free SIM card from giffgaff).
      Hope this helps,

  2. Moira said:

    I was given a Verizon Moto E 2nd Generation, I live in the UK. I have put a 3 (UK) sim in phone and I cannot get the phone to recognise the sim.
    I tried changing the Network from CDMA/LTE to GSM/LTE then go to the Preferred Network Mode but cannot get an option for 4G, there is only the option for LTE/CDMA?

    Can you please help me as this is beyond me now.

    1. Ken Lo
      Ken replied:

      Hi Moira,
      Thanks for your comment. I’ve taken an in-depth look at the specifications for the Verizon Moto E 2nd Generation. Unfortunately, it won’t work on Three in the UK. This is because Three uses WCDMA band 1 (2100MHz), LTE band 20 (800MHz EUDD) and LTE band 3 (1800MHz). The Verizon Moto E doesn’t support any of these bands.
      If you’d like to use the Moto E in the UK, try a SIM card from either EE, O2 or Vodafone (those three networks have GSM 900 & GSM 1800 which is supported on the Verizon Moto E). Please note: this is only 2G coverage – it should be fine for calling and texting… browsing is also possible but will unfortunately be super-duper slow!
      Hope this helps,

  3. Yoosuf said:

    Hi I have a sprint iPhone 6 and I just landed in London from the U.S. I had previously called my sprint international services to see if there will be any outrages charges using texts/calls and data and they all told me no except 20 cents a minute per call. They told me to go to my settings, turn enable LTE off, turn roaming ON, and and then turn international CDMA off. And connect to a UK carrier, and the one I am connected to is O2-UK and my aunts wifi at her home. Is this all correct information? Or I will be left with a hefty bill when I come home to the U.S, I am here for a month currently. Do I need to get a temporary SIM card???? I’m so lost! I know roaming charges a lot, so why would sprint tell me to turn it on? They said there will be no additional charges.

    1. Ken Lo
      Ken replied:

      Hi Yoosuf,
      Thanks for your comment. Unfortunately, I can’t help you with the answer to this question: it depends on what Sprint charges you for roaming. I’d advise you to double-check these charges directly with Sprint (I’m no expert on American tariffs). The good news is you definitely won’t pay a penny when using your aunt’s wi-fi connection. For this reason, I strongly advise using wi-fi whenever you can.

    2. Arne replied:

      Alright. I just wrote a giant comment about how you should disable dataroaming, because you’re in another continent and that they definitely will charge you insane high prices, but then I found this article from April 2015:,2817,2481186,00.asp

      Leave dataroaming on then (it’s free anyways), text your homies as much as you want (it’s completely free), and calling home is really cheap (20c/min.! It’s more expensive to call from EU to EU, and you’re calling from EU to US…)

      You shouldn’t worry about using data if you’re not on WiFi, as it’s completely free, but keep in mind that you’ll only get access to the 2G network.
      2G -> GPRS / EDGE
      3G -> UMTS / HSPA
      4G -> LTE
      GPRS, EDGE and UMTS are really slow. And you won’t get anything faster than EDGE. Sending iMessages will work, Snapchat might work REALLY slowly (only photo’s, no video’s), but downloading a game or Facetiming your family… I don’t think so.
      You said you’re on Sprint: well, 2G is about the same as 1x for Sprint and Verizon. Ever had the 1x? That’s the speed you’ll get. It’s pretty useless.
      You could leave LTE off, since you won’t get any LTE reception. It looks like Sprint only has an agreement with O2’s 2G network. If can choose to only connect to 2G (Settings > Cellular data > Voice & data > 2G), than I’d reccomand you to do so. I don’t know if Sprint actually does have an agreement that allows their customers to roam on the 3G or 4G (LTE) network, but if they do, you might get charged, since they’re only talking about the 2G network in the article. You will have to have iOS 8.3 or higher for this, and your carrier must allow this (I tink all US carriers do, even without iOS 8.3, maybe it’s only for our European carriers it requires iOS 8.3).
      If you can’t find ‘Voice & Data’, or can’t find 2G, just disable LTE. You should see ‘O2-UK GPRS’ or probably ‘O2-UK E’. It’s really slow, but free.
      So don’t worry, and leave dataroamin on.

      There’s absolutely no need to get a sim card in the UK, and I’m not sure if you can get a sim card out of a CDMA phone. If you have the iPhone 6 on a contract with Sprint, it wouldn’t work anyways, since they made the iPhone work with Sprint sim cards only.

      Have a great time in the UK!
      Greetings from Belgium.

  4. Stacy said:

    Hi, I am traveling to the UK and planning to use Three’s SIM card. What compatibility should I look for in an unlocked phone? Do you have any suggestions for type of phone under 100 with GPS/maps usage?

    1. Ken Lo
      Ken replied:

      Hi Stacy,
      Thanks for your comment. To use your handset on Three, it needs to support 3G connectivity at 2100MHz (this may be described on the spec sheet as WCDMA 2100, HSDPA 2100, HSPA+ 2100 or something along those lines). With regards to the best value handset, I’m afraid it’s quite difficult to make a recommendation! For readers of this website, the Moto E 4G is a really popular choice (approx £90 for 4G connectivity and all of the features you mention in your comment).

      1. Stacy replied:

        Thank you ken! Very helpful

  5. Luis said:

    Hi Ken,
    I hope you can help me… I recently bought a mobile phone in the US. I am planning to move to London in a few months. I was wondering if my BLU Vivo IV will work in UK.
    Thanking you in anticipation…

    1. Ken Lo
      Ken replied:

      Hi Luis,
      Thanks for your comment. I’m pleased to report the BLU Vivo IV should work fine in the UK – just be sure to make sure it’s unlocked before you leave the US. In the UK, we use GSM 900 (2G coverage on O2 and Vodafone), GSM 1800 (2G coverage on EE) and HSDPA 2100 (3G coverage on all major networks).
      Hope this helps,

  6. Neil said:

    Hi Ken

    I have just purchased a TBS3202b gps phone watch that only supports 2g GSM
    850/900/1800/1900MHz. I have tried 2 x pay as you go micro sims from EE and O2 and the watch does not recognise both cards, is there a SIM card provider in the uk that has 2g only SIM cards as I think that the cards I have are 4g compatable and the watch will not recognise the cards.
    Your help would be Much appreciated.


    1. Ken Lo
      Ken replied:

      Hi Neil,
      Thanks for your comment. Both EE and O2 still provide 2G coverage on their mobile SIM cards (on a 2G-only device, you’re still able to get 2G coverage). The only UK network not offering any 2G coverage is Three and all of the MVNOs running on Three’s network. In theory, the specs of your watch phone suggest they should work on both EE and O2 (EE uses GSM at 1800MHz whereas O2 uses GSM at 900MHz). If you’re having problems getting the smartwatch to work, you may need to contact the manufacturer.

  7. Amarjit Ranu said:

    Hi Ken
    I am thinking of buying a HTC M9+ which is available from SZ CH.
    Would I be right in assuming that as Virgin works on EE frequency I would be able to use the mobile in the UK. Or would I be best to change mobile supplier and if so which would be the best to move over to.

    Thank you for your help.

    Kind Regards


    1. Ken Lo
      Ken replied:

      Hi Amarjit,
      Thanks for your comment. Virgin uses GSM 1800 for their 2G coverage (the same as EE). For 3G, they use 2100MHz (the same as for EE and for all other networks in the UK). Hence, your HTC M9+ should work fine in the UK on Virgin Mobile. With regards to 4G: unfortunately, Virgin Mobile doesn’t give you access to EE’s 4G network. Hence, you’ll only be able to access 2G and 3G services.
      Hope this helps,

  8. Karina said:

    Hi Ken,

    I am planning to buy a Samsung Galaxy S6 edge in HK. Will it work with my Three network when I am back at UK please?
    From Samsung HK customer service, their phone support
    FDD-LTE (4G): 700,800,850,900,1800,1900,2100,2600,AWS
    TD-LTE (4G): 1900,2300,2500,2600
    UMTS/WCDMA (3G):850,900,1900,2100
    TD-SCDMA (3G): 1880,2010
    CDMA2000 (3G): 800
    GSM (2G): 850,900,1800,1900
    CDMA (2G): 800

    From Three UK customer service, they only can say they use 800 and 1800 band. Not sure whether they match? Can you please help?

    Also will I need to do the regional locking 5mins call in HK before I leave as well?

    Many thanks,


    1. Ken Lo
      Ken replied:

      Hi Karina,
      Thanks for your comment. Three uses band 3 (1800MHz) FDD-LTE and band 20 (800MHz) FDD-LTE for their 4G services in the UK. Hence, according to the specs on the Samsung Hong Kong website, it should be OK to use the handset in the UK.
      With regards to region locking: I’m not sure whether Samsung applies this to handsets in Hong Kong (check any labels on the box to see whether it’s mentioned). To be safe, it would be best to make a 5 minute phone call in Hong Kong if possible.
      Hope this helps,

      1. Karina replied:

        Thanks Ken.

        Very helpful advise.


  9. elsa said:

    Hi, tell me I go a new cell phone from china but the frequencies and network are: WCDMA/GSM,
    My micro SIM is 3G Tmobile contract will work in this cell phone or not?
    I need to know to buy this cell phone.
    Thank you
    I live in UK England

    1. Ken Lo
      Ken replied:

      Hi Elsa,
      Thanks for your comment. Based on the bands you’ve described, the phone should indeed work on T-Mobile in the UK. For 2G, T-Mobile UK uses GSM 1800. For 3G, they use WCDMA 2100.

  10. Subhaan Mahmood said:

    I recently bought a Samsung Galaxy s6 which is an AT&T US version but it is unlocked.
    These are the frequencies:

    • GSM 850 / 900 / 1800 / 1900
    • HSDPA 850 / 900 / 1900 / 2100
    • LTE band 1(2100), 2(1900), 3(1800), 4(1700/2100), 5(850), 7(2600), 8(900), 17(700), 20(800)

    Will my Three contract sim work in this phone?

    1. Ken Lo
      Ken replied:

      Hi Subhaan,
      Thanks for your comment. Providing the handset is unlocked, it should work without problems on Three in the UK. For reference, Three uses HSDPA 2100 for 3G connectivity and LTE band 3 (1800MHz) for 4G connectivity. It’s worth double-checking to see whether the handset has a US region-lock before you bring it to the UK. If it does, you’ll need to make a 5 minute phone call on US networks before it’ll work in the UK.

  11. Akidcalledquest said:

    Wassup Ken

    Because I also have a HTC one M8 (only it’s a China import) , to get 4g coverage in the UK I would also have to be on either EE or Three wouldn’t I?

    1. Ken Lo
      Ken replied:

      Hi there,
      I’m not entirely sure what the supported LTE bands are on the Chinese HTC One M8. However, assuming it’s the normal Asian version which supports band 1 (2100MHz), 3 (1800MHz), 7 (2600MHz), 8 (900MHz) and 28 (700MHz), you’re right: it’ll only work on EE and Three.

  12. harold said:

    Hi Ken, not sure if my comment was sent the first time. Basically, I purchased a Yezz Andy 5T handset in USA and want to know if it will work in the UK on my 3G contract with t-mobile. I have attached link of device.

    Many thanks

    1. Ken Lo
      Ken replied:

      Hi Harold,
      Thanks for your comment. In the UK, all four mobile networks use 2100MHz for their 3G service. So yes, according to the spec sheet, the handset you mentioned should work in the UK :)
      Hope this helps,

  13. Chas Hydfe said:

    A friend’s brother is visiting soon from Australia, and wants to know if he will be able to get a SIM in the UK which will work in his smartphone.
    It is this phone :-
    5.0″IPS Touch Dual SIM Unlocked Dual Core Android Smart mobile phone 3G WiFi GPS

    It gives the following info, I am struggling to work out if it will operate successfully in the UK

    SIM1(Standard SIM Slot) : 2G (GSM 850/900/1800/1900MHZ)/ 3G (WCDMA 850/2100 MHz)

    SIM2(Micro SIM Slot) : 2G (GSM 850/900/1800/1900MHZ), (Don’t Support 3G Or 4G Network)

    Any help would be great, thanks.


    1. Ken Lo
      Ken replied:

      Hi Chas,
      Thanks for your comment. The phone should work fine in the UK providing it isn’t locked to a network in Australia.
      O2 and Vodafone use GSM900 for 2G.
      EE uses GSM1800 for 2G.
      All four networks (EE, O2, Three and Vodafone) use WCDMA2100 for 3G.
      For other networks (e.g. giffgaff and Tesco, see my article here for more information.
      Hope this helps!

  14. Spandana said:

    Dear Ken,

    I am from India. I recently bought Lenovo A6000. I am providing the gsmarena link here:

    From your very helpful review above, I think it is going to work in UK. I shall be travelling to UK in August, and wish to use a pay-as-you-go sim of Lyca/ Lebara. Can you confirm whether the set is compatible (regarding the GSM 2G/3G bands)?

    Also, are any of the pay-as-you-go sims available in the Airports micro-sim? It seems that the mobile companies have stopped making mini-sim phones. Should I carry a mini-sim set that I know has worked well in UK (my previous set, samsung galaxy S advance is one such set)?

    I must say you are doing one hell of a job, helping all of us out here.

    1. Ken Lo
      Ken replied:

      Hi Spandana,
      Thanks for your comment. I can happily confirm that the Lenovo A6000 supports 2G, 3G and 4G coverage here in the UK. For 2G coverage in the UK, you need 900MHz or 1800MHz. For 3G, you need 2100MHz (O2 and Vodafone also have some 3G coverage at 900MHz but it’s not actually necessary for your phone to support this). For 4G, you’ll need 800MHz, 1800MHz or 2600MHz (the Lenovo A6000 supports all three).
      Longer answer (if you’d like more detail):
      – Lycamobile uses coverage from O2. Required bands are GSM 900 for 2G, HSDPA 900/2100 for 3G and LTE 800 for 4G.
      – Lebara Mobile uses coverage from Vodafone. Required bands are GSM 900 for 2G and HSDPA 900/2100 for 3G. 4G coverage isn’t currently available on Lebara.
      As a side note, take a look at my comparison table for international calling using your smartphone (you might find giffgaff offers better value than both Lycamobile & Lebara Mobile).
      Finally, it shouldn’t be a problem getting a SIM card in any of the three sizes (Mini SIM, Micro SIM and Nano SIM are all easily available). Do be aware if you’re buying at the airport you’ll normally pay more for the SIM card itself (a shop in the airport may charge around £10 whereas you can get the SIM card for free elsewhere in the UK).
      Hope this helps!

      1. Spandana replied:

        Thanks boss! Cheers!

  15. Becca said:

    Hi Ken,

    Love your page. Just got a quick question about buying phones abroad as well. I planning to buy the new Samsung Note 4 when I’m on holiday in Hong Kong. Would there be any limitations on which networks I could have it on when I return back to the UK (preferable on 3g or 4g networks)?

    Thanks in advance,

    1. Ken Lo
      Ken replied:

      Hi Becca,
      Thanks for your comment. The Hong Kong version of the Galaxy Note 4 (SM-N910U) should work on all 2G and 3G networks here in the UK. With regards to 4G, it unfortunately lacks support for Band 20 LTE (800MHz). This means you’re unable to use it on the O2 4G network and the Vodafone 4G network. You still have access to Band 3 LTE (1800MHz) which will give you some coverage on EE and Three (see my article on the UK’s 4G landscape).
      One more thing: Samsung implements region locking on their Galaxy smartphones. Before you’re able to use the handset in the UK, you’ll need to activate it on a network in Hong Kong (this requires you to make a voice call of at least 5 minutes on a Hong Kong network).
      Hope this helps!

  16. Jay said:

    Hi Ken – This is very useful information:o)

    I was wondering if you knew if the Sharp Aquos Crystal/Crystal X can be used in the UK? I am aware that it has been released in Japan and the USA, but I am not sure if it is just CDMA? – Where are the specs, but I can’t seem to find any info on the bands, the UK service providers use for 2/3/4G…

    1. Ken Lo
      Ken replied:

      Hi Jay,
      Thanks for your comment. I’ve taken a look at the link you provided – the handset would work on any 2G or 3G network here in the UK. For reference, O2 and Vodafone use GSM 900MHz; EE uses GSM 1800MHz. For 3G, all four networks operate on UMTS 2100MHz (O2 and Vodafone also have some UMTS 900MHz but I would generally ignore them as coverage is very limited). For 4G, the handset would only work on Three or EE (only these two networks have LTE at 1800MHz).
      Hope this helps!

  17. mike said:

    Hi I have a lenovo S8/S898t+
    TD-SCDMA 850/2100Mhz. it works fine on my contract talktalk Sim on 2g, but is their any other UK sims I could get to use the 3g? Thanks

    1. Ken Lo
      Ken replied:

      Hi Mike,
      Thanks for your comment. Your Lenovo Golden Warrior S8 will only work on 2G networks here in the UK. This is because the handset supports GSM 900 and GSM 1800 (these frequencies are used for 2G in the UK).
      For 3G, we use WCDMA technology. Unfortunately, WCDMA coverage is not incompatible with the TD-SCDMA technology used by China Mobile.

  18. Stephen said:


    I wish to know if T-Mobile in the UK will be compatible with a phone that support the following networks & frequency:

    Networking GSM/WCDMA
    2G: GSM 850/900/1800/1900MHz
    3G: WCDMA 900/2100MHz

    Some of the research I have done suggests that it will, but I found a site that said that for 3G the phone would have to be compatible with both 1700 AND 2100 MHz, while others say just 2100 MHz, although I may be getting details for America and UK confused. At the end of the day I would to just confirm if the phone will work with T-mobile in the UK.

    Many thanks in advance for any help.

    1. Ken Lo
      Ken replied:

      Hi Stephen,
      Thanks for your comment. I’m glad to report your phone will work fine on T-Mobile in the UK. T-Mobile in the UK uses GSM 1800MHz and WCDMA 2100MHz, both of which are supported on your handset.
      WCDMA 1700/2100MHz refers to the AWS band used by T-Mobile in the USA (it’s not applicable for users in the UK).

      1. Stephen replied:

        Hi Ken


        I have had a similar reply from US-T-mobile community forum which along with your reply re-enforces my own research.

        Have good 2015.

        Regards Stephen

        1. Ken Lo
          Ken replied:

          No worries Stephen: glad to be of help! Wishing you a happy new year and all the best for 2015 :)

  19. Satnam said:

    I have purchased a Motorola Nexus 6 from the US (Sprint unlocked). I live in the UK and have a micro sim that i cut to nano sim size to use in the device. This worked without any issue and i also ordered an ‘official’ nano sim from EE.

    EE deactivated my old (cut) sim and activated the new one, this however does not work.

    Is there a difference between the micro sim and the nano sim that might cause this?

    Or does the phone itself not allow it to use the uk nano sim?

    In the phone menu accessed by *#4636#*#* i only see 4 bands:

    USA Band
    Band mode 6
    Band mode 7
    Band mode 15

    I’m not sure if this is related to the SIM or phone.

    Many thanks in advance, Satnam.

    1. Ken Lo
      Ken replied:

      Hi Satnam,
      Thanks for your comment. It’s really odd that the self-cut Nano SIM is working in the phone but the officially provided Nano SIM isn’t. There shouldn’t be any significant differences between the physical SIM cards so it is rather odd that things aren’t working properly. If possible, I would probably try using the new nano SIM within another handset (this will allow you to double-check the nano-SIM is working properly). You could also try using a nano-SIM from a different mobile network (this will tell you if it’s a problem specifically with the EE nano-SIM or rather a problem with nano-SIMs in general).
      Good luck in finding the solution to your problem,

  20. riho said:

    Hi there I have just bought a mobile phone called Xiaomi Red Note. There are 2 versions; 3g and the 4g, I purchased the 4g version. Could you tell me if this phone would work in the UK? Thank you

    1. Ken Lo
      Ken replied:

      Hi Riho,
      Could you kindly provide the specifications for the handset you bought? I’ve found the GSMArena page on the Xiaomi Redmi Note 4G (not sure if this is the one you bought?). If so, according to that page, 3G only works with TD-SCDMA technology and 4G with TD-LTE technology. Unfortunately, in the UK, we use neither of those technologies (we use WCDMA and FDD-LTE). Hence, the handset wouldn’t work on 3G or 4G networks here in the UK. 2G connectivity should still be fine (the handset supports GSM 900 & 1800) but your download speeds will be incredibly limited.

      1. riho replied:

        Thank you for your reply.

        I bought mine directly from China through a friend, and according to her, there are two types of 4G specifications on the phone of the same model:

        (1) TD-LTE/FDD-LTE/WCDMA/GSM and

        (2) TD-LTE/TD-SCDMA/GSM.

        The one that I bought is the (1) version with the FDD-LTE and WCDMA. Since you mentioned that the UK have both of those, I guess the phone will work here.

        1. Ken Lo
          Ken replied:

          Hi Riho,
          Fantastic! Yep… WCDMA and FDD-LTE are the things you’re looking for. As well as checking the technologies, you’ll also need to check the supported frequencies. For 3G connectivity, it must support WCDMA at 2100MHz. For 4G connectivity, you’ll need FDD-LTE at 800MHz or 1800MHz (that’s band 3 or band 20). EE and Vodafone should also theoretically support band 7 FDD-LTE (2600MHz) though I’m not sure whether they’ve actually begun to roll out this type of coverage.

          1. riho replied:

            Hi Ken,

            Thank you! I’m glad I made the right purchase! Thanks again for helping me out


  21. Rob said:

    Hi Tim,

    I have just bought a ZGPAX S8 for my son for Christmas. but I cant get the sim to work in it.

    it says on the box it is 3g compatible and works with wcdma 2100mhz

    My son has “THREE” NETWORK SIM CARD we are in the uk.

    Should this sim card work on this watch phone.

    Thank you for your time.


    1. Ken Lo
      Ken replied:

      Hi Rob,
      Thanks for getting in touch with your question. A device supporting WCDMA 2100MHz should in theory work on the Three network. Hence, I’m not totally why it isn’t working in this situation. I’d recommend trying a few things:
      1) Check the SIM card from Three is working in another device (this will rule out a problem with the SIM card).
      2) Try the device with a couple of other SIM cards (e.g. from giffgaff or another network, you can order a free SIM card here). For instance, other networks also have 2G support so they might work better in the device. For instance, a watch will have a very small antenna so may struggle to receive coverage on 3G.
      If after trying both things the watch is still failing to work, you might then need to contact the network.

  22. JIm Regan said:

    Hi Ken

    You seem to have offered some great advice in the comments so i hope you don’t mind if I jump in with a questions too.

    I have been using the BLU Win HD phone in the US and am coming back to the UK. Would this work back there?

    Its specs are 4G 850/1700 or 850/1900/2100.

    Many thanks


    1. Ken Lo
      Ken replied:

      Hi Jim,
      Thanks for your comment! Which version of the BLU Win HD are you planning to buy? I found the handset listed on Microsoft’s website but the specs are listed as follows:
      2G: GSM 850 / 900 / 1800 / 1900
      3G: HSDPA 850 / 1900
      Based on the info from Microsoft’s website, the handset would only work on 2G networks here in the UK. However, I suspect I’m probably looking at a different phone to the one you were looking at seeing as the listed specifications differ in your comment?

  23. Adam said:

    I’m thinking of purchasing a new Nexus 6 from the US and I was wondering if it would work on the three / 3 network.
    I live in the UK and the price for the phone here is about £110 more for the 64GB model. If the unlocked model from the Google play store in the USA works on three with their 3g and 4g networks, I definitely won’t hesitate to buy one.
    Thanks in advance

    1. Ken Lo
      Ken replied:

      Hi Adam,
      Thanks for your comment. I believe the North American version of the Nexus 6 (model number XT1103) should work OK on the Three network (for 3G you’ll need band 1 WCDMA; for 4G you’ll need band 3 or band 20 LTE). The North American version of the Nexus 6 supports band 1 WCDMA and band 3 LTE. However, there’s no support for band 20 LTE (800MHz) so 4G coverage could be limited or intermittent in some areas.

      1. Brian replied:

        Hi Ken! I’m planning a trip to London and Paris and I’d really love to use my Nexus 6 (U.S. version XT1103) while there (mostly for navigation and data service).

        I’d really like your advice on what brand of SIM card to get. Will it make any difference which network I choose?

        I’m looking for a pay-as-you-go SIM with the best coverage/bandwidth. I’d like to be able to top up with a non-UK credit card if possible. Most important thing to me good 4G service – cost is secondary. I’ll be making calls and texts back to the US also. Thanks!

        1. Ken Lo
          Ken replied:

          Hi Brian,
          Thanks for your comment. My recommendation is to get a SIM card from Three. The reason being you’re able to use the SIM card in France at no extra charge (see here for more information). Upon your arrival in the UK, you’ll need to find a Three retail store (alternatively, you can also find the SIM card in many supermarkets). You’ll need an All-in-One add-on to take advantage of the Feel At Home offer.
          Hope this helps,

  24. Kyle said:


    I have a Sprint LG G3 and I am in the UK. I picked up a Three SIM card, but I have a feeling I made a mistake. Am I unable to use the Three network on my LG G3 by Sprint?

    1. Ken Lo
      Ken replied:

      Hi Kyle,
      I’ve just taken a look at the LG website: the LG G3 on Sprint (model number LS990) supports UMTS 2100. This means it should work on any UK network providing it isn’t locked to Sprint.
      Hope this helps,

  25. Paul said:


    Hope you can help. I am interested in buying a HTC One M8 from the US to use in the UK.
    My question is, would the phone actually work on the 4g network in the UK on T Mobile. I am confident it would work on 2g and 3g but have read different stories with regards to 4g.
    From looking at the spec of the US phone, I can see that it has different frequency coverage for Sprint and Verizon as per below:

    2G Network – GSM 850 / 900 / 1800 / 1900 – Sprint, Verizon
    CDMA 800 / 1900 – Sprint, Verizon

    3G Network – HSDPA 850 / 1900 / 2100 – for Sprint
    HSDPA 850 / 900 / 1900 / 2100 – for Verizon
    CDMA2000 1xEV-DO – for Sprint, Verizon

    4G Network – LTE 800 / 1900 / 2600 – Sprint
    LTE 700 / 1700 / 1800 / 2100 / 2300 / 2600 – Verizon

    I have checked T Mobile’s frequency which it uses for 2g, 3g and 4g and it appears that the Verizon phone would be compatible in the UK if it were to be Unlocked.
    Despite this I have read that it would still not work due to Verizon not having LTE 800 and Sprint not having LTE 2100 so neither network is compatible?
    Can you confirm if this is indeed the case and if so, if any of the other US phone networks would work in the UK.


    1. Ken Lo
      Ken replied:

      Hi Paul,
      Thanks for your comment. Before I answer your question, it’s worth noting that T-Mobile doesn’t offer a 4G service here in the UK. To get 4G, you’ll need to “upgrade” to the 4GEE brand (this is true regardless of your handset).

      For 2G coverage in the UK, you’ll need to have either GSM 900 (for O2 and Vodafone) or GSM 1800 (for EE). Three doesn’t offer 2G coverage.
      For 3G coverage in the UK, you’ll need HSDPA 2100 for all of the UK networks (some limited coverage is also available on HSDPA 900 but I wouldn’t rely on it being available).
      For 4G coverage in the UK, you’ll need LTE 800 for an optimal experience (see my article on the UK’s 4G landscape) on O2 and Vodafone. For EE and Three, it’s normally best to have LTE 1800 support (they also have coverage at LTE 800 but coverage & speeds are currently more limited). LTE 2600 is yet to launch properly in the UK so isn’t useful at present.

      Concluding from this, the Verizon phone should work in the UK providing it’s unlocked. It would work on any of the 3G networks but would only work on EE and Three if you wanted 4G coverage (it doesn’t support LTE 800). The Sprint version would give you 4G coverage on Vodafone and O2 (it doesn’t have LTE 1800). A version of the phone bought in the UK would support both types of frequencies and would hence give a slightly smoother experience.

      Hope this helps!

      Based on the specifications you’ve written in your e-mail, neither handset

      1. Paul replied:

        Thanks Ken

        Answers it perfectly.

        Just out of curiosity, do you know if AT&T handsets would work in the UK if they were unlocked?


        1. Ken Lo
          Ken replied:

          Hi Paul,
          I believe it should be possible to use an unlocked AT&T handset whilst in the UK. You’ll need to make sure it’s a quad-band GSM handset (it’ll need to support the UK 2G frequencies of 900MHz and 1800MHz). For 3G connectivity, you should also check for WCDMA or HSDPA 2100 support.
          Hope this helps!

          1. Paul replied:

            Thanks Ken

  26. Giovanni said:

    Hi ken,

    I’m looking at the thl t6s as a temporary phone until the new year, but i’m still uncertain if it will support the O2 network I would appreciate some clarification as I think I will only have partial 3g coverage in London.


    1. Ken Lo
      Ken replied:

      Hi Gio,
      Thanks for your comment. I’ve just taken a look at the THL T6S smartphone. According to the specs, it supports quad-band GSM (GSM 850/900/1800/1900) and WCDMA (3G) at 850MHz and 2100MHz. As O2 uses 900MHz for GSM (2G) and 2100MHz for WCDMA (3G), it should support 2G and 3G fully. You won’t have access to the WCDMA service at 900MHz but in reality this shouldn’t make very much of a difference (2100MHz should be available across London).
      Hope this helps,

  27. Kiran said:

    I recently brought a mobile in India to use in UK, it has GSM/GSM dual sim phone. I did not get a chance to use it in India, when I put the sim in UK the signal is alright, i can send messages but the only problem I am facing is when I make a call I can hear the other person but they cannot hear me, do you think it could be something to do with network bands?

    1. Ken Lo
      Ken replied:

      Hi Kiran,
      I’m not sure if this would happen due to network band support (unless for some reason, your handset only supports the UK downstream frequency). Have you tried making the call on another UK network? (e.g. if you’re using a 900MHz network such as O2 or Vodafone, you could try EE which uses 1800MHz). Something else to try is making the call with your hands-free kit in (this would allow you to tell if the problem is actually related to the microphone not working).

      1. Kiran replied:

        Thanks for the reply Ken, the problem was with the microphone, I tried recording a video and it was recorded without any voice, though there was lot of noise when the video was recorded. So now I have asked for a replacement with the manufacturer. The good thing is it works with bluetooth and headphones.. so still been able to use it.


  28. Tim said:

    I recently bought a GTmobile sim-only card for my unlocked Samsung phone with a view to phoning a friend abroad during August – now in September I still had credit on it as I kept using it for local/national calls until it stopped. I was surprised to find out that it's another virtual provider on the O2 network, but only charges 2p/min for landline and mobile networks.

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