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.


Like this tip? Get the most from your mobile phone...

  • Discover brand new ways to use your mobile phone
  • Techniques to get more out of your mobile phone for less
  • Be the first to learn about new mobile technology

Enter your email to receive free regular Ken's Tech Tips:

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 34 comments from readers. You can add your own comment here.

  1. 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!

  2. 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.

  3. 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 :)

  4. 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,

  5. 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


  6. 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.

  7. 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?

  8. 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.

  9. 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,

  10. 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

  11. 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,

  12. 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.


  13. 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.

Leave a Reply

E-Mail Notifications: By default, I'll drop you an e-mail when there's a reply to your comment. If you don't want to receive such a notification, please select the "Don't Subscribe" option from the dropdown menu above.