How to unlock your Samsung Galaxy Smartphone from a UK Mobile Network

January 14th, 2015

If you’d like to use a Samsung Galaxy smartphone on a different mobile network, you might first need to unlock it. This article will show you how to unlock a Samsung Galaxy handset from networks in the UK.

Galaxy S to Galaxy S5If you bought your Samsung Galaxy smartphone here in the UK, either on a Pay Monthly contract or on a Pay As You Go tariff, the phone will probably be locked to the mobile network from which you bought the handset.

If you’d like to use the handset on another network, you’ll first need to go through the process of unlocking it. Unlocking your smartphone is often necessary if you want to use it on a different mobile network (e.g. to take advantage of a cheaper SIM only deal, to use a different SIM card when travelling abroad or when giving the handset to friends or family). You can also unlock your Samsung Galaxy smartphone to boost its resale value on eBay and other websites.

In this article, we’ll take you through the process of unlocking a Galaxy smartphone one step at a time. We’ll show you how to check if your handset is already unlocked, how to find the IMEI number on your handset and how to unlock your Galaxy smartphone from each of the UK’s major mobile networks. We’ll also discuss the costs of unlocking and how long it’s expected to take on each of the networks. Finally, we’ll discuss some free methods of unlocking your Galaxy handset (not recommended for the majority of users).

Benefits of Unlocking

There are three main benefits to unlocking your Samsung Galaxy handset. Firstly, you’ll be able to benefit from cheaper deals at home (whether that’s moving over to a SIM only contract or another Pay As You Go network which offers lower rates). You can also save money when travelling abroad by using a local SIM card rather than roaming on a UK contract. Finally, unlocking your handset will make second-hand usage of the phone much easier. It’s also likely to boost the resale value of your handset.

Cheaper Deals At Home

SIM card

Unlocking your phone & switching to a SIM only deal will allow you to benefit from cheaper deals in the UK.

Once you’ve completed the minimum term of your contract (normally 24 months), you can save substantial amounts of money by moving over to a SIM only contract.

A SIM only contract gives you generous amounts of minutes, texts and internet at a monthly price that’s often around £20/month cheaper than your current contract. Often, people can save around £200/year simply by switching to a SIM only contract. You can keep the same number when moving mobile networks but you’ll need to unlock your handset before you do this.

At present, our recommended SIM only deals for use with a Galaxy smartphone are as follows:


SIM-only contracts normally have a 12 month commitment. For greater flexibility, you can choose a one-month rolling SIM only contract. For a complete overview of all the available options, you can see our full listing of SIM-only contracts in the UK.

Save Money When Travelling Abroad

Going Abroad

You can also save money when travelling abroad e.g. by taking advantage of the Feel At Home offer.

If you’re travelling abroad and using your normal UK SIM card, it’s possible to quickly incur huge charges for roaming.

In Europe, you can normally expect to pay 18.8p/minute for outgoing phone calls, 5.9p for every text message you send and 19.8p for every megabyte you download. A specialist SIM card will bring these prices down to either £10/month or £1.99/day (it depends on the country you’re visiting). You’ll need to unlock your Samsung Galaxy smartphone before using a different SIM card for travelling abroad. For more information, see our guide to the best value SIM cards for travelling in Europe.

When using your phone outside of Europe, typical roaming charges are substantially higher. You can expect to pay around £1.50/minute, 50p per text message and around £6/MB when accessing the internet. When data roaming on a normal UK SIM card, you can easily run up a £60 bill with only one day of typical data usage. Hence, when travelling outside the EU, it’s often a good idea to buy a SIM card locally in your country of travel. You’ll need to unlock your handset before you go in order to use a different SIM card abroad.

Are you travelling to Spain, the USA, France, Italy or one of 14 other countries?

If you’re planning to travel to one of 18 selected countries, the best way of using your smartphone abroad is to take advantage of Three’s Feel At Home offer. With Feel At Home, there’s no extra charge for using your smartphone abroad. Better still, the offer is available regardless of which network you normally use in the UK. Simply order one of their All-in-One Pay As You Go SIM cards: you can benefit from the offer in any unlocked Galaxy smartphone. A £10 top-up will give you 500MB, 100 minutes and 3000 texts (all available to be used when abroad).

Network Minutes Texts Internet Monthly
Three 100 3,000 500MB £10.00
Three 300 3,000 25GB £15.00

The “All in One” Pay As You Go bundles can be used with Three’s “Feel At Home” offer. The inclusive minutes, texts and internet can be used abroad in any “Feel At Home” country. The £15 bundle has a fair usage policy of 25GB/month when in a “Feel At Home” country.

Countries included in Feel At Home: Australia, Austria, Denmark, Finland, France, Hong Kong, Indonesia, Israel, Italy, Macau, New Zealand (available from April 1st 2015), Norway, Republic of Ireland, Spain (available from April 1st 2015), Sri Lanka, Sweden, Switzerland and the United States of America.

Order Three Pay As You Go SIM Card (with £10 bundle) »

Second-Hand Usage & Resale Value


An unlocked smartphone can be used on any network.

Unlocking your smartphone will also have benefits in terms of second-hand usage and increased resale value.

If you’re passing an old Galaxy smartphone to friends or family members, unlocking it first will allow them to use the Samsung Galaxy handset on their network of choice. They can also benefit from a low-cost SIM only deal.

If you’re selling your old handset (e.g. on eBay or Gumtree), unlocking the handset first may also boost the resale value of your phone. You’ll also increase the potential audience of buyers (otherwise, your phone can only be used by customers on one network).


In the UK, it’s 100% legal to unlock your handset for use on other networks. All major UK mobile networks provide unlocking as an official service. Unlocking your phone will not affect the warranty status or the way in which your handset works.

For some older Samsung Galaxy devices, there are unofficial methods through which you’re able to unlock the handset. Unofficial methods to unlock your handset may affect the warranty status. They could also change the way your handset works. For this reason, whenever possible, we would always recommend unlocking your handset officially via your network operator.

Step-by-Step Guide To Unlocking

Samsung Galaxy S5There are four simple steps to unlocking your Samsung Galaxy smartphone:

  1. Check if your Galaxy handset has already been unlocked. Some smartphones are already unlocked at the point when you buy them. It’s worth double-checking before you go through the rest of the process of unlocking your phone.
  2. Find out your IMEI number. The IMEI is a 15-digit code which uniquely identifies your Samsung Galaxy smartphone (no two handsets will share the same IMEI). You’ll need to have the IMEI number before you’re able to unlock the handset for other networks.
  3. Ask your mobile network to unlock the Galaxy smartphone. You’ll need to follow different instructions depending on the network you’d like to unlock the handset from. See the unlocking instructions for each UK network here.
  4. Enjoy using your new network or SIM card. It can take anywhere between a couple of hours and up to 10 days for your smartphone to be unlocked. Once you’ve entered the unlocking code in your phone, the handset will work on any compatible network in the world (enjoy cheaper rates at home and cheaper rates when away).

Through the rest of this article, we’ll discuss each of the steps in order.

Check Whether Your Handset Is Already Unlocked

The easiest and most reliable way to check whether your Samsung Galaxy smartphone is locked to a network is to order a free Pay As You Go SIM card from a different mobile network that you aren’t currently using. After inserting the new SIM card inside of your handset, there are two possibilities on what might happen:

  1. Your smartphone shows the name of the new network. If the name of the new network appears on your lock screen, your smartphone successfully accepted the SIM card you inserted. If the SIM card you used was from a different network to the one you were using originally, it would indicate that your Samsung Galaxy smartphone is already unlocked (there are a couple of exceptions, please see the notes below*). If your handset is already unlocked, it won’t be necessary to go through the rest of the unlocking process.
  2. You get an error such as “Invalid SIM” or you’re asked to input a “SIM network unlock PIN”. This error message will mean your Samsung Galaxy handset is locked to a network. It won’t accept SIM cards from a different network unless you first complete the network unlocking process (see below).

* Caveats: A giffgaff SIM card will work in your Samsung Galaxy smartphone even if it’s locked to O2. A SIM card from EE will also work in Samsung Galaxy smartphones locked to T-Mobile. You should bear this in mind when testing the phone with a SIM card from another network (ideally you should test the handset with a network that uses a different coverage provider).

When ordering a free SIM card for the purposes of testing whether your smartphone is unlocked, you’ll probably be asked which size of SIM card is required for your phone. The following table shows which size of SIM card is required in different models of a Samsung Galaxy smartphone:

Handset SIM Card Required UK Model Number
Galaxy S Smartphones:
Galaxy S Standard SIM GT-I9000
Galaxy S2 Standard SIM GT-I9100
Galaxy S3 Micro SIM GT-I9300, GT-I9305
Galaxy S4 Micro SIM GT-I9505
Galaxy S5 Micro SIM SM-G900
Galaxy S ‘Mini’ Smartphones:
Galaxy S3 Mini Standard SIM GT-I8190
Galaxy S4 Mini Micro SIM GT-I9190
Galaxy S5 Mini Micro SIM SM-G800F
Handset SIM Card Required UK Model Number
Galaxy Note Smartphones:
Galaxy Note Standard SIM GT-N7000
Galaxy Note 2 Micro SIM GT-N7100
Galaxy Note 3 Micro SIM SM-N9005
Galaxy Note 4 Micro SIM SM-N910F
Galaxy Ace Smartphones:
Galaxy Ace Standard SIM GT-S5830
Galaxy Ace 2 Standard SIM GT-I8160
Galaxy Ace 3 Micro SIM GT-S7275
Galaxy Ace 4 Micro SIM SM-G357FZ

If your smartphone isn’t listed in the table above, you can see a full list of smartphones and the required SIM card sizes on this page. A combi-SIM (provided by giffgaff, EE and O2) will work in any Samsung Galaxy smartphone manufactured to date.

Finding Your IMEI Number

If you’ve already double-checked to make sure unlocking is required, the next step is to find out the unique IMEI number on your Samsung Galaxy smartphone.

Galaxy S3 IMEI Number

The IMEI is a 15-digit code starting with 35.

An IMEI number is 15-digits long and will always be unique to your specific handset only (no two smartphones will ever have the same IMEI number). For Samsung Galaxy smartphones, the first two digits of the IMEI number should be 35. Make a careful note of your IMEI number: you’ll need it later on when requesting your unlock code.

There are two ways of finding the IMEI number on your phone:

  • Use the ‘Settings’ app. You can find the IMEI number through the Settings application. On your handset, navigate to Settings > More… > About device > Status. The IMEI number should be listed approximately half-way down in the list. You’ll probably need to scroll a bit to see it (see the screenshot for an example of how it looks). Take a careful note of the IMEI number: you’ll need it later on when unlocking your handset.
  • Use the ‘Phone’ app or dialler. Another way of finding the IMEI number is to open your phone’s dialler (just as if you were going to make a call). Dial *#06# (star hash zero six hash). Your phone’s IMEI number should pop up in a new window. You will only need the first 15 digits of the number displayed (ignore the slash and any numbers that follow it).

Unlocking Instructions By Network

EE, Orange & T-Mobile

EE, Orange and T-MobilePay Monthly. It’ll cost £20.42 to unlock a Samsung Galaxy handset if you’re a Pay Monthly customer on EE, Orange or T-Mobile. To qualify for unlocking, you must have had your contract for at least six months. The contract must also be currently active (so you should get the unlock processed before moving to another network). You must also be up-to-date on all payments on your account.

It’s worth noting that EE have stringent requirements about the person who bought the handset you’re unlocking. They will only unlock your Samsung Galaxy handset if the device was provided with your current contract. Hence, you won’t be able to unlock a second-hand device. If the smartphone you’d like to unlock was originally purchased by another person, you should ask that person to submit the unlocking request for you.

The £20.42 fee for unlocking will be charged to your next monthly bill. You can submit the unlocking request through a form on EE’s website. It can take up to 10 days to receive your unlocking code.

Pay As You Go. For customers on EE Pay As You Go, it’ll cost £20.42 to unlock your Samsung Galaxy handset. The fee is deducted from your Pay As You Go airtime balance so you should ensure you have enough credit before requesting the unlock.

As of December 2014, EE has removed the requirement to have used your Pay As You Go handset for more than 6 months (the six month requirement now only applies to Pay Monthly customers). Their conditions for unlocking still require the handset to be associated with that Pay As You Go account: “the IMEI of the device to be unlocked must be registered on the account.”

After requesting an unlock from EE, you should receive the networking unlocking code within a maximum of 10 days.


Pay Monthly. Pay Monthly customers on O2 can unlock their handset totally free of charge at any time during their contract. Simply fill out your details in the online unlocking form (you’ll need to provide account information, some security details and your handset IMEI number). It can take up to 7 days for a Samsung Galaxy unlock to be processed.

Pay As You Go. If you’re an O2 Pay As You Go customer, you’ll need to wait until at least 12 months after your original purchase for O2 to unlock your handset. After the twelve months have elapsed, it’ll cost £15 to unlock your Galaxy handset. The £15 charge is deducted from your Pay As You Go airtime balance so make sure you have enough credit before filling out the form on O2’s website.

Note: Customers intending to use their Samsung Galaxy handset on giffgaff won’t actually need to unlock their handset from O2 (a giffgaff SIM card will work in O2-locked handsets). For O2 Pay Monthly customers, it’s still worth requesting an unlock (it’s free). For customers on O2 Pay As You Go, you can save £15 by foregoing the unlock. To join giffgaff, you can order a free SIM card here.

Tesco Mobile

Tesco Mobile

Pay Monthly. For customers on Tesco Pay Monthly, it’s normally £20 to unlock your Samsung Galaxy smartphone for use on other networks. If the minimum term of your contract has already ended (this normally happens if you’ve had the handset for more than 24 months) or if you’ve paid off the ‘Phone payment’ part of your ‘Anytime Upgrade’ plan, the £20 unlocking fee will not be charged. To request an unlocking, call the Tesco Mobile aftersales support number on 0345 300 6660.

Pay As You Go. There’s a £20 charge to unlock your Samsung Galaxy handset if you’ve had the phone for less than 12 months. After you’ve had the handset for more than 12 months, the unlocking fee will not be charged. You can request an unlock by calling the Tesco Mobile aftersales support number (0345 300 6660).


Pay Monthly & Pay As You Go.  If you bought your Samsung Galaxy handset in 2014 or 2015, it should already be unlocked for use on any network. Handsets bought before the 1st January 2014 could still be locked to the Three network. They can now be unlocked totally free of charge by filling out this form on Three’s website. It can take up to 7 days for the unlocking request to be processed.

If you don’t currently have an active SIM card on the Three network, you can order a free one for the purposes of unlocking. The SIM card may take up to two working days to arrive at your home. If you’d like to expedite the process and to get a SIM card more quickly, Pay As You Go SIM cards are available for £1 from your local Three store.

More information can be seen on the Three help pages.

Virgin Mobile

virginPay Monthly. On Virgin, many Galaxy handsets are already unlocked when provided on a contract. If your smartphone wasn’t unlocked when it was originally provided, there’s normally a £15.32 fee to unlock it for use on other mobile networks (the exact unlocking fee applying to your mobile can be found in their Pay Monthly call charge table). To request an unlock, call Virgin customer services on 789 (calls are free from your Virgin Mobile handset).

Pay As You Go. It’ll cost £15.32 to unlock your handset from Virgin Pay As You Go (see the tariff table for more information). You’ll also need to register your handset details with Virgin for security as per section 7.5 of their terms and conditions. Call Virgin customer services on 789 to request your unlock (calls are free from your Virgin Mobile handset).


Pay Monthly. You can unlock a Samsung Galaxy handset from Vodafone providing you’ve made at least three clear payments on your account (in practice, this means you’ll be three or more months into your Pay Monthly contract). It’s £19.99 to unlock your handset if you’ve had the phone for less than one year. After the first year, Vodafone will unlock your handset for free. Request a unlock through the Vodafone website: it can take up to 10 days before you receive the unlocking code.

Pay As You Go. Customers on Vodafone Pay As You Go are able to unlock their handset at any time. The cost is £19.99 which will be taken from your Pay As You Go balance. For this reason, you should top-up by £20 or more prior to requesting an unlock from Vodafone. You can submit your unlocking request through Vodafone’s website: it can take up to 10 days to receive your unlocking code.

Free Unlocking Methods

In the past (e.g. with the Galaxy S3 and earlier devices), it was reasonably easy to unlock your handset for free. You would normally need to “root” your handset (a process which would void the phone’s warranty) and you’d need to run a special app to generate the unlocking code.

As of July 2012, Samsung has tightened up the process around handset locking. On newer versions of their software, the handset will check for unauthorised unlocking every time it’s restarted or when the software is updated. Phones unlocked through an unofficial method may therefore become locked again in the future. For this reason, we strongly recommend you pay the small fee to unlock your handset properly.

Samsung Galaxy S3

Older devices such as the Galaxy S3 can sometimes be unlocked through unofficial methods.

If you’d still like to unlock your handset for free, the following methods are currently available:

  • Galaxy S4 (except EE): Free unlock via the Service Mode menu.
    If you have a Galaxy S4 provided in the UK (excluding those provided on EE), there’s a method to unlock your handset for free. It involves using a secret menu known as “Service Mode” – there’s a blog post on giffgaff with more information. You can also follow their step-by-step video instructions.
  • Galaxy S3 and earlier, Galaxy Note 2 and earlier: GalaxSIM (requires root, £2.59 unlock via app).
    If you have a rooted Galaxy S, Galaxy S2, Galaxy S3 (excluding the 4G version), Galaxy Note or Galaxy Note 2, it’s possible to unlock your phone through the GalaxSIM app. There’s a £2.59 in-app purchase before the app will actually unlock your handset. See the XDA Developer forums for more information.
  • Galaxy S2: Unlock Code Finder (requires root, free unlock via app).
    For users of an older Galaxy S2, the Galaxy S2 Unlock Code Finder will try to find an unlock code for your phone. Please note: the app was last updated in 2011. Hence, it probably won’t work if you’ve updated the software on your phone. Your handset must be rooted for the application to work.

More Information

For more information, please see our in-depth guide to mobile phone unlocking. If you’re looking to upgrade to a new Galaxy smartphone, please see our round-up of the best Samsung Galaxy deals.


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

  1. Kate said:

    I am looking to buy a Samsung galexy s4 off little woods it’s a sim free phone, as I already have a contract sim I just smashed my phone, I am currently on 3, would this network work in the sim free phone because I no 3 have been a bit funny in the past

    Thanks kate

    1. Ken Lo
      Ken replied:

      Hi Kate,
      Thanks for your comment. A SIM-free Galaxy S4 will indeed work on the Three network (though make sure you have a micro-sized SIM card). The only SIM-free handsets, I’m currently aware of, which cannot be used on the Three network are 2G-only devices (this is because Three only provides 3G and 4G coverage).
      Hope this helps!

  2. Aargee said:

    I have just bought a new sim-free Galaxy 3 Neo which I assume is therefore unlocked. I want to use it as PAYG and after reading your excellent reviews I have shortlisted giffgaff and Three.
    My question: if the one I choose proves unsatisfactory and I decide to try the other, will installing the sim have locked the phone? Or can I simply replace the sim without the complications of having to unlock the phone?
    I would much appreciate your advice and know-how.
    Many thanks.

    1. Ken Lo
      Ken replied:

      Hi Aargee,
      Glad the articles have been of help! If you buy a SIM-free Samsung handset, it’ll always be unlocked for use on any network. For instance, you could try a giffgaff SIM card first and then a Three SIM card after. The handset will still be unlocked for use on either network.
      Automatic locking only happens on SIM-free iPhones from the Carphone Warehouse.
      Hope this helps,

  3. serena said:

    I’m no techie, but your tips are amazing and easy to follow! Thank you for saving me £10!!!

  4. John said:

    I have just been given an S2 but I can’t get it to work on O2. The phone must be unlocked as I can make calls and text with a virgin sim in it and a vodafone sim. I have seen something about Tesco putting a double lock on their phones but don’t know whether this is the problem or not

    any advice?

  5. Demon_man said:

    There is actually a free way to unlock the S3 and the Note 2, and its perfectly safe, it was published on gsm arena.

  6. roubina said:

    I asked my operator (02) for an unlock code. it is free as i am a pay mmonthly customer…4 times they gave me the same code
    and several times i tried entering the code but not working. tOday they found out it could be because I am not in uk. I am in Mauritius for the next 6 six months i and they say they rather not tempt me to try again as my phone could be permanently blocked. They want me to come back to uk and see a guru there. I have no phone since one week and i don't know what to do. What happens if it has been permanently blocked ? Is there any solution to unlock it without going to uk?

    1. JKay6969 replied:

      If you lock your phone inadvertently while trying to unlock it you can obtain an unfreeze code and enter that before entering the unlock code correctly.

      I am not aware if you will be able to unlock your phone officially while outside the UK but if you have a tech savvy family member you may want to post it home, get them to unlock it then post it back. I know this is relatively expensive and time consuming but the other alternative would be fly home, unlock your phone and fly back. Just a thought.

  7. Shree said:

    i have seen web sites advertising instant unlocking service for very little money. apparently they give you unlocking code,is this safe?reading yr tip, it seems that one should steer clear of these practises.

    1. Ken Lo
      Ken replied:

      Hi Shree,

      My personal advice is to go to your network and unlock it the official way: it's the safest and it'll definitely work. Whilst some of these other services might work, some of them are scams and some of them will unlock your device in a way which might leave it open to security vulnerabilities in the future.


  8. Adrian said:


  9. Pete said:

    If I unlock my S2 and upgrade it to ICS o/s will I still be ale to perform my existing contract with Orange?

    1. Ken Lo
      Ken replied:

      Hi Pete,

      Your software update to Ice Cream Sandwich will not affect your existing contract with Orange.

      Hope this helps!


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