How to unlock your Samsung Galaxy S2 from O2, Orange, Three, T-Mobile or Vodafone

May 24th, 2012

If your Galaxy S II is unlocked, you can benefit from cheaper SIM only deals at home and better value deals when you go abroad.

If you purchased your Samsung Galaxy S II (Samsung GT-I9100) on contract from one of the UK’s mobile operators, it’s likely that it’ll be network-locked. This means it can only be used on the network from which you originally purchased it from (as they subsidised the cost of your handset when you purchased it). This causes problems if you want to switch to a different network, use a cheap SIM card when abroad or if you want to pass your Galaxy S II to a friend or family member on a different mobile network. Having a locked handset will also stop you from taking advantage of a super-cheap smartphone SIM-only deals when your contract ends.

In order to use your Galaxy S II on a different network, you’ll need to unlock it first. This article discusses the unlocking with regards to the Galaxy S II in the UK including how to check whether your handset is locked and how to obtain all of the necessary information to unlock your phone. We also outline the different methods of unlocking a Galaxy S II and how much they will cost, including a method that allows you to unlock your phone for free.

What are the benefits of unlocking my Samsung Galaxy S II?

There are multiple benefits to unlocking your handset:

Unlocking allows you to use your Galaxy S II on a different network.

Is it legal to unlock a handset?

It is totally legal and within the law to unlock a mobile phone handset and official unlocking methods are provided by all of the mobile operators. All of the UK’s networks will unlock your phone upon request but  may charge a fee for doing so.

How do I find the IMEI number on my Samsung Galaxy S2?

In order to unlock your Galaxy S2, you’ll need to have your IMEI number to hand. This is a unique 15-digit code that begins with 35 and uniquely identifies your device.

You can find the IMEI number on your handset by opening the phone dialler application and entering *#06#. Write this down somewhere: you’ll need it later on to unlock your phone.

How do I check whether my Galaxy S II is locked?

If you purchased a Samsung Galaxy S II (GT-I9100) directly from a mobile operator either on Pay Monthly or Pay As You Go, chances are that it’ll be network locked. This means you’ll need to unlock your handset before using it on a different mobile network.

One way of checking whether your handset is locked is to order a free Pay As You Go SIM card from another mobile network. Slot this into your handset. The SIM card should be recognised unless your handset is locked, in which case your phone will ask for an unlock code.

Another method of checking whether your handset is locked is to use Samsung’s built-in status checker utility. You can access this by opening up the phone dialler and entering the code *#7465625# (these numbers correspond to the code *#SIMLOCK#). This will open up a dialog entitled “Personalizatiob Status” (sp.). An example screenshot of the dialog is shown on the right.

There are four different ways in which a Galaxy S II can be locked:

  • Network Lock (NCK)
  • Network Subset Lock (SCK)
  • Service Provider Lock (SPCK)
  • Corporate Lock

If your Galaxy S II has been fully unlocked, all of these settings should read “OFF” (as pictured on right). If your handset is locked, the “Network Lock” item will read “ON”. Some networks may also apply additional SCK or SPCK locks. You may need this information later on when unlocking your handset.

The official methods of unlocking a Samsung Galaxy S2 are as follows:

How can I unlock my Samsung Galaxy S2 from O2?

If you purchased your Galaxy S2 from O2 on a Pay Monthly contract, they will unlock it S2 free of charge through their online form.

For O2 Pay As You Go customers, you’ll need to wait until 12 months after your original purchase before you can unlock your Galaxy S2. They will charge £15 to your Pay As You Go account for this.

How can I unlock my Samsung Galaxy S2 from Orange?

Orange will unlock your Galaxy S2 providing that you’ve had it for at least 3 months and providing that you do not owe any money on your account. They charge an “administration fee” of £20.42 for the unlocking process. You can unlock your handset by contacting Orange customer services.

How can I unlock my Samsung Galaxy S2 from Three?

Three will unlock your Galaxy S2 for the one-off cost of £15.32. According to their website, you’ll need to have had your phone for at least 30 days and you’ll need to have paid your first bill on-time. They add that you’ll “pay a one-off fee of £15.32. You’ll need to pay this fee over the phone when you call us for your unlock code, using a debit or credit card”.

To unlock your Galaxy S2, call Three customer services on 333 from your handset or 0843 373 3333 from a landline to begin the process.

How can I unlock my Samsung Galaxy S2 from T-Mobile?

According to T-Mobile, you can unlock your handset by contacting their customer services team. Other than that, information is fairly low on the ground regarding unlocking the Galaxy S2 from T-Mobile. If you’ve had success unlocking a Samsung Galaxy S2 from T-Mobile, drop us a comment below and let us know your experiences.

How can I unlock my Samsung Galaxy S2 from Vodafone?

Vodafone Pay Monthly customers can obtain a free unlock code from Vodafone through their online form. According to Vodafone, the turnaround time for Samsung unlock codes is 7-10 working days.

Pay As You Go customers will need to pay £19.99 to unlock a Galaxy S2. This is deducted from your airtime allowance so you should top-up by at least £20 before requesting an unlock code.

See the Vodafone website for more information.

Is it possible to unlock my Galaxy S II for free?

If your Galaxy S II has been rooted, you can try the free “Galaxy S2 SIM Unlock” application. This has been developed by Chainfire at the XDA Developers website. This option is only recommended for advanced users as you will need to “root” your device. Rooting your device will invalidate your warranty and can introduce security vulnerabilities later on. It can also render your device permanently unusable if carried out incorrectly. We would thoroughly recommend unlocking your phone through official methods whenever possible.

The newer Galaxy S III will be available from the end of May.

Some small shops and newsagents will advertise the fact that they can unlock your handset. They will typically do this using the “free unlocking” methods that we have discussed above (such methods invalidate your handset warranty). We would recommend unlocking your handset officially through your network provider if at all possible.

Will the unlocking instructions here also work for Samsung’s other Galaxy devices?

In general, these unlocking instructions should apply for most of Samsung’s Galaxy-range Android devices including the Samsung Galaxy S (GT-I9000) and the Samsung Galaxy Note (GT-N7000). You can check the model number which applies to your device through the Settings > About phone > Model number menu item. The “Galaxy S2 SIM Unlock” application will not work on other devices, though alternative applications may be available.

I’m looking to upgrade to the Samsung Galaxy S3. What are the options?

The Samsung Galaxy S3 is available on all of the major UK networks. We’ve got a full comparison of the different tariffs available across the UK’s mobile networks.


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

  1. serena said:

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

  2. 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?

  3. 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.

  4. 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.


  5. Adrian said:


  6. 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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