The first is called 'Unlock It Free' which can be found here: www.unlockitfree.com/ It is a basic website and is one of the easiest ways to unlock your phone online.
The homepage will welcome you and ask for the model number of your phone. Enter this into the box and click 'find'. You will then be brought to the window seen in the screenshot. In the appropriate boxes, enter in your IMEI number, phone model, country and service provider. You can get the IMEI number of your handset by typing *#06# on the home screen as though you were dialling a phone number or you can look under the battery for a fifteen digit number.
Click 'Generate' once you have all the information entered in correctly. The program will then churn out seven different free unlocking codes for your mobile phone.
When you have the foreign SIM card in your phone you will be asked to put in one of these codes. Use the first one. Over half of the people have success on the first code. If it doesn't work, use the last one. Around 80% of people would have their phone unlocked by now. If yours hasn't, use two more and it should be unlocked.
Don't enter in any more than four however as this will disable your phone meaning you will have to re-enable it. This service works for over 90% of the users who try to unlock their phone with it.
Another site to use is 'Trycktill', the link to which can be found here: www.trycktill.com/eng/
On the homepage, click 'Unlock' along the top menu bar. This will bring you to a page written in a language you will not understand unless you are Swedish. Down the bottom of the page click on the Union Jack (British) flag. This will reload the page in English.
You will see the drop down menu asking for your phone make. Once this is filled in it will ask you for the model number, then the IMEI. Once you have filled in all of the criteria, agree to the terms and conditions by checking the little box and click 'Generate Code'.
When the results page loads you will see a code to the right. You will be given a set of individual instructions directly beneath the code on how to unlock the phone. These will differ slightly depending on the make of the phone.