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:

NetworkMinutesTextsInternetMonthly
Cost
Plusnet Mobile1,500Unlimited5GB£10.00
ThreeUnlimitedUnlimited4GB£10.00
BT MobileUnlimitedUnlimited3GB£10.00
inc. £5 discount
giffgaff500Unlimited3GB£10.00
iD Mobile5005,0003GB£10.00
Tesco Mobile5005,0001GB£10.00
Vodafone1,000Unlimited1GB£11.00
O21,000Unlimited1GB£13.00
EE1,000Unlimited1GB£15.99

* On BT Mobile, a £5/month discount is available for customers living in a BT Broadband household.

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, Hong Kong, Indonesia, Israel, Macau, New Zealand, Singapore, Sri Lanka or the USA, 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:

Network Minutes Texts Internet Monthly
Cost
Three 3,000
to UK
3,000
to UK
5GB £15.00
Three 3,000
to UK
3,000
to UK
12GB
9GB abroad
£20.00

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 X iPhone 8 iPhone 8 Plus iPhone 7 iPhone 7 Plus iPhone SE
Apple Store £999.00 £699.00 £799.00 £549.00 £669.00 £349.00
Argos £999.00 £699.00 £799.00 £539.00 £649.00 £299.00
Carphone Warehouse £999.00 £699.00 £799.00 £549.00 £649.00 £299.00
Currys £999.00 £699.00 £799.00 £539.00 £699.00 £299.00
John Lewis £999.00 £699.00 £799.00 £549.00 £669.00 £299.00
PC World £999.00 £699.00 £799.00 £539.00 £699.00 £299.00
Unshackled £699.00 £799.00 £549.00 £669.00 £379.00
giffgaff* £699.00 £799.00 £499.00 £649.00 £299.00
Three* £699.99 £799.99 £569.99 £669.99 £379.99

* Requires a £10 minimum top-up with purchase of iPhone.

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 88 so far

We'd love to hear your thoughts and any questions you may have. So far, we've received 88 comments from readers. You can add your own comment here.

  • suzanne clinton said:

    Hi ken, 02 contacted me about a new deal,I am currently with Vodafone. I sorted out the tariff that I wanted and got my Pac code from Vodafone. I am stuck now because my phone isn’t unlocked and o2 never mentioned that my phone should be to get a sim off them. What do I do now please?

    • Hi Suzanne,
      Many thanks for your comment, and sorry to hear about the problem you’ve encountered moving from Vodafone to O2. It sounds like the logical next step might be to request an unlocking code from Vodafone – you just need to follow the instructions on this page. There’s no charge unlocking your handset from Vodafone (all that’s required is you’ve used it for at least 3 months on Pay Monthly, or 30 days on Pay As You Go).
      Ken

  • Hi
    great informative site!I am travelling to South Africa shortly and want to be able to surf the net and email from a place with no wifi. What is the best option for me? I have a Sony smart phone that I bought from O2, then took out a sim only contract with Bt that involved O2 unlocking the phone. I assume it is unlocked but have taken your advice and ordered a free sim from Asda to try. Should I buy a sim card in South Africa (or get my relative to get it) and buy data……. will it work ok?
    thanks

    • Hi Lorraine,
      Thanks for your comment. Yes, your best bet would probably be getting a local SIM card while you’re out there in South Africa (as most UK networks will have extortionate roaming charges there). As you say, it’s definitely worthwhile making sure your handset is unlocked before you go, and ordering a SIM card from another network like ASDA Mobile is a great way to do this!
      Ken

  • Hello. I’m having a torrid time getting a tesco phone unlocked. It’s a MOTO G and the contract is up so I’ve moved to talk talk on a sim only deal. Tesco have given me a code but it doesn’t work. They say they’ll send me another one in twenty days. I have bought one off eBay and it’s exactly the same as the one I received from tesco. I have powered off my phone, inserted the talk talk SIM card, and turned it on again. It says “sim network unlock pin” but when I input the code it says unsuccessful. I have spoken to talk talk and they say everything is fine at their end. I have read that tesco phones are double locked. Is that true? If so what does that mean? Is there anything I can do about it?

    With many thanks PAUL.

    • Hi Paul,
      Thanks for your comment. I believe ‘double locking’ means the handset is specifically locked to Tesco Mobile (as opposed to some MVNOs that only lock the handset to their coverage provider e.g. in this case, you’d be able to use the handset on O2 and other O2 MVNOs).
      Either way, this shouldn’t affect the unlocking process for your smartphone. Once you’ve received the code from Tesco Mobile and got it to work on your phone, it will then be unlocked for use on any network. Sorry I can’t help any further – but the onus is now on Tesco Mobile to provide you with an unlock code that works.
      Ken

      • Not true sometimes Tesco cannt unlock the phone. Whether thats to do with the double locking indon’t know. O2 sim card didn’t work in the phone. So after a few calls it was sent back to their mobile repair to hard unlock. They couldn’t do it and send out a brand new samsung j3 instead.

        Bought a Nokia 3310 and made £70 profit in the mean time.

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