Everything you need to know about mobile unlocking. Find out which networks lock their phones, how to unlock your handset and where to buy a new unlocked smartphone.

LockedIn the UK, some mobile networks will lock your smartphone to their network so you won’t be able to use the handset on a different network. The process of removing these restrictions is known as ‘mobile unlocking’. Following a successful unlock, network restrictions will be removed and you’ll be able to use your mobile phone on any compatible mobile network.

In this article, we’ll tell you everything you need to know about mobile phone unlocking. We’ll start from the benefits of unlocking your handset and how it allows you to get cheaper deals both in the UK and abroad. We’ll then look at the handset locking policy on each UK network before discussing how you can unlock an existing smartphone. Finally, we’ll discuss how to buy a new unlocked smartphone from retailers in the UK.

Benefits of Unlocking

There are three main benefits to having an unlocked smartphone:

  1. Access to more mobile networks & cheaper tariff options. With an unlocked handset, you’ll be able to access SIM-only and Pay As You Go deals from many more mobile networks. You can often save hundreds of pounds per year by switching your mobile network or tariff.
  2. Save money when travelling abroad. If you’re travelling abroad, particularly outside of Europe, you’ll normally need to pay international roaming fees. With an unlocked handset, you can side-step international roaming charges by buying a SIM card in the country you’re visiting.
  3. Increased resale value & second-hand usage options. An unlocked handset will retain its value much better, which is advantageous if you’re looking to sell it on places like eBay or Gumtree. You can also give your unlocked handset to friends or family members, who’ll be able to use it on their mobile network of choice.

It’s perfectly legal to unlock your smartphone and all UK mobile networks provide an official way for you to do it. Unlocking doesn’t affect the warranty on your device (assuming the unlock is processed officially through a request to your mobile network).

Access Cheaper Tariffs In The UK

For many people, one of the key benefits of unlocking their smartphone is having the ability to use it on a different mobile network in the UK. This means having a much wider-selection of cheaper SIM-only deals, saving you money on your phone bill every month.

The following table shows a sample of some SIM-only deals and what you’re able to get on different networks from just £10/month:

NetworkMinutesTextsDataMonthly Cost
(may rise during contract)
iD MobileUnlimitedUnlimited60GB£10.00
Sky MobileUnlimitedUnlimited5GB£10.00

It’s easy to keep your existing phone number when moving to another network. For a complete overview of all the available SIM-only options, please see our full guide to the UK’s best value SIM-only deals.

Save Money When Travelling Abroad

If you’re travelling abroad, especially outside of Europe, it can be expensive to use international roaming on your normal UK SIM card.

If you’d like to use a different SIM card when travelling abroad, you’ll first need to unlock your smartphone.

If you’re travelling to Australia, Brazil, Chile, Colombia, Costa Rica, Hong Kong, Indonesia, Israel, Macau, New Zealand, Peru, Singapore, Sri Lanka, the USA or Vietnam, it can be worthwhile ordering a Pay As You Go SIM card from Three. You’ll have access to the Three’s Feel At Home Around The World offer, allowing you to use the following UK allowances when you’re abroad:

to UK
to UK
UK & abroad
to UK
to UK
UK & abroad
to UK
to UK
UK & abroad

With an “All in One” Pay As You Go bundle, the inclusive minutes, texts and internet can be used abroad in a Feel At Home country.

In Europe, you’ll normally be able to use your phone at no additional charge on all UK-based SIM cards.

In other countries, it might be worth considering buying a SIM card from one of the local mobile networks as this will normally be a lot cheaper than roaming on your UK-based SIM card.

For more information, please see our in-depth guide to travelling abroad with your mobile phone.

Increased Resale Value & Second-Hand Options

An unlocked smartphone has better resale value on eBay & Gumtree.

An unlocked smartphone also gives you additional benefits in terms of increased resale value and more second-hand usage options.

If you’re selling your smartphone on websites like eBay and Gumtree, an unlocked smartphone will often sell faster and for more money. This is because the potential audience of buyers is much wider (otherwise, you’re restricting your set of potential buyers only to customers of one mobile network).

If you’re giving your handset to a friend or family member, having an unlocked handset will also give them many more options. They’ll be able to use the handset on their mobile network of choice (including on one of the best-value SIM-only or Pay As You Go deals).

Which Mobile Networks Lock Their Smartphones?

  • BT Mobile
  • EE
  • giffgaff
  • iD Mobile
  • O2
  • Sky Mobile
  • Tesco Mobile
  • Three
  • Virgin Mobile
  • Vodafone

In the UK, only some mobile networks will lock smartphones to their network whereas others will typically provide their handsets unlocked.

The following table gives a quick overview of which mobile networks currently lock their smartphones:

Mobile Network Are Handsets Locked To The Mobile Network?
BT Mobile No. Handsets are provided unlocked.
EE Yes. Handsets are normally locked to EE.
giffgaff No. Handsets are provided unlocked.
iD Mobile No. Handsets are provided unlocked.
O2 Yes. Handsets are normally locked to O2.
Sky Mobile No. Handsets are provided unlocked.
Tesco Mobile Yes. Handsets are normally locked to Tesco Mobile.
Three No. Handsets are provided unlocked.
Virgin Mobile Yes (PAYG only). Handsets are locked on Pay As You Go, and unlocked on contract.
Vodafone Yes. Handsets are normally locked to Vodafone.

Some mobile networks decide to lock their smartphones as they may “subsidise” the upfront cost of the handset. By offering handsets as a loss-leader, they try to attract new customers to their network. The network-locking mechanism provides a way for networks to stop you from taking a subsidised device and immediately using it on another mobile network.

On request, all UK mobile networks will unlock your smartphone, but this may be subject to a small fee or eligibility requirements (e.g. they may ask you to have been a customer on their mobile network for a certain amount of time).

Find Out Whether Your Phone Is Locked

SmartphonesThe table above should give you a good indication about whether your smartphone is likely to be locked to a mobile network.

If you’re still unsure whether your smartphone is unlocked, the best way to check is by ordering a free Pay As You Go SIM card. The SIM card you order should come from another mobile network (though there are a couple of caveats, see * below for more details).

When your new SIM card arrives, insert it into your smartphone. If the SIM card is accepted and you can see the name of the mobile network being shown on the screen, then your smartphone is unlocked and there’s nothing further you need to do. If you see an error message such as “SIM Not Valid” or “Invalid SIM” then your smartphone is currently locked and you’ll need to unlock it.

SIM Not Valid: The SIM card that you currently have installed in this iPhone is from a carrier that is not supported under the activation policy that is currently assigned by the activation server. This is not a hardware issue with the iPhone. Please insert another SIM card from a supported carrier or request that this iPhone be unlocked by your carrier.

If you see a message saying “SIM Not Valid” or “Invalid SIM”, your smartphone is currently locked to a network.

(* Caveat: You should ideally test your phone using a SIM card from a mobile network that uses a different coverage provider. For instance, a giffgaff SIM card may work in some O2-locked smartphones as giffgaff makes use of coverage from O2).

How To Unlock Your Smartphone

UnlockThere are four simple steps to unlocking your smartphone:

  1. Find out whether your smartphone is already unlocked. If you’re still unsure, a good way to check is to order a free Pay As You Go SIM card from another network.
  2. Obtain the IMEI number for your smartphone. If you need to unlock your smartphone, the next step is to obtain your 15-digit IMEI number. This is a unique identifier for your smartphone and can be found by entering *#06# on your telephone keypad (star hash zero six hash).
  3. Ask your mobile network to unlock the smartphone. Depending on your mobile network and tariff, this can cost you up to £15. For more information, see our guides on unlocking an iPhone and unlocking a Samsung Galaxy.
  4. When the unlock has been processed, enjoy using your new mobile network or SIM card. It can take up to 10 working days for your handset to be unlocked. Once the unlock is complete, you can enjoy cheaper rates at home along with cheaper rates when you travel abroad.

For more information, follow our step-by-step guides to unlocking an iPhone and unlocking a Samsung Galaxy smartphone. If you have an Android smartphone from a different manufacturer, you can still follow most of the instructions in our Samsung Galaxy article (the menus on your phone may look a little bit different but the instructions for unlocking will be exactly the same).

Where To Buy A New Unlocked Smartphone

Apple iPhone

If you’re looking to buy a new unlocked iPhone, the best place to buy from is normally John Lewis. John Lewis provides permanently-unlocked iPhones at the same price as going directly to Apple, but with the addition of a two-year guarantee at no extra price. You’ll also benefit from the John Lewis “never knowingly unsold” promise.

Order an unlocked iPhone from John Lewis →

In the past, SIM-free iPhones from the Carphone Warehouse and some other third-party retailers would automatically lock themselves to the first mobile network used. Today, this is no longer the case for the newly-purchased iPhones so you can also buy an unlocked iPhone from any of the following retailers:

Retailer iPhone XS iPhone XS Max iPhone XR iPhone X iPhone 8
John Lewis & Partners £999.00 £1,099.00 £749.00 £749.00 £599.00
Argos £999.00 £1,099.00 £749.00 £749.00 £599.00
Carphone Warehouse £999.00 £1,099.00 £749.00 £799.00 £599.00
Currys PC World £999.00 £1,099.00 £749.00 £799.00 £599.00
Apple £999.00 £1,099.00 £749.00 £599.00

If your iPhone was purchased before July 2017, please see our guide to unlocking SIM-free iPhones.

All Other Smartphones

Android Smartphones
For all other smartphones, there’s a wide variety of online retailers where you’re able to buy an unlocked smartphone.

If you’d like to buy an unlocked smartphone that isn’t an iPhone, there’s a wide choice of retailers you’re able to choose from.

If you’re happy to get the phone on a Pay Monthly contract, try the Carphone Warehouse or Mobiles.co.uk. Both of them will provide you with an unlocked handset on a 24-month contract (the contract will often be the same price or slightly cheaper than getting it directly from your mobile network).

On Pay As You Go, you can get a handset from either giffgaff or Three (both giffgaff and Three provide their handsets unlocked so you’ll be able to use them on the mobile network of your choice).

Finally, for a SIM-free smartphone (without a contract or SIM card), you can go to one of the following online retailers:

You can also buy a SIM-free smartphone directly from the manufacturer website (e.g. from the Google, HTC, Huawei, Motorola, Samsung or Sony official websites).

More Information

For more information about unlocking your smartphone, please see our step-by-step guides to unlocking an iPhone and unlocking a Samsung Galaxy smartphone. Once you have an unlocked smartphone, you may find it useful to read our guide on the best value SIM-only deals.

Your Comments 104 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 104 comments from readers. You can add your own comment here.

  • Hi Ken,

    I’m having an issue at the moment with EE around my Samsung Galaxy Note 9 being locked to their network. I purchased the phone on 15th July 2019 as a brand new, unlocked phone from Amazon, sold by Amazon and advertised as an unlocked UK model.

    I have been on a sim only deal with EE and that SIM was used in the phone without issue, however I have now swapped over to the Smarty network on 30th July this year. However I have been unable to use the phone as Smarty have said that whilst their sim is activated, my phone is showing as being locked to EE.

    I have queried this with EE, who have still not unlocked the phone 3 weeks later, as to how they could have locked it to them in the circumstances, only to be told that some phones can be locked to a particular network the first time a SIM is put in to it. They actually sent me a link to your article ‘Apple iPhone: When SIM-Free Doesn’t Always Mean Unlocked’ as a means of explaining it despite the note at the bottom of the article saying this isn’t the case with Android devices!

    Any ideas what is going on here?

    • Hi Jon,
      Thanks for your comment. The automatic locking to the first network used only applied to some SIM-free iPhone devices in the past. This shouldn’t be happening on any Samsung phones like the Galaxy Note 9.
      Unfortunately, I’m not quite sure what has happened here, but it might be worth getting in touch with either Samsung or Amazon. There are only two explanations I can think of:
      (1) Your phone was never unlocked to start with (i.e. you were actually sold a phone that was locked to EE).
      (2) Your phone isn’t actually locked to EE (it might be failing to work on Smarty for another reason e.g. because it has the wrong APN internet settings).

  • James Morrison said:

    Hi Ken, I was interested in buying outright an Apple iphone SE Because I want a dual sim phone. Unfortunately the SE can only take one physical SIM card the other being electronic. This would be fine but I am in a sim only contract with Vodafone until next February and they do not support electronic sims. I was hoping they would then when I go to a variety of places overseas I would then just have to put the physical sim in from that country.
    Can you tell me a good alternative to the Apple iPhone SE ?

    • Hi James,
      Thanks for your comment. I’m not sure whether this helps, but I believe you can transfer your Vodafone SIM card to eSIM. Alternatively, if you’re looking for a device with dual physical SIM cards, do have a look at the devices from Huawei and Honor. If you pick up one of their older models, this will still have access to Google Play Store (some newer devices won’t have access, so I’d recommend staying clear of them for the time being).

  • Hi Ken, How do you rate TCL 10 Pro mobile phone which I’ve got 60 days to decide if I like or send it back? It sees so advanced compared to the Samsung Galaxy S2 which I currently own. Thanks for your time.

    • Hi Terry,
      Thanks for your comment, and a very good question! Unfortunately, I haven’t used or tried the TCL 10 Pro so I wouldn’t be very well placed to advise on it. It should definitely be a decent upgrade from the Galaxy S2, though possibly worth comparing it against something like the Pixel 3a which is probably my personal favourite at the moment in the mid-range category.

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