How to unlock a mobile phone for free
Sometimes we’ve got a really nice phone, but want to change which provider we use, and can’t because the phone is locked to that provider. Unlocking mobile phones is possible in most cases, but it’s not always free so here are a few tips on how to get your phone unlocked without spending lots doing so.
What is unlocking and why would I want to do it?
Mobile phone unlocking simply means removing the restriction that allows it to only accept SIM cards for one network. Unlocking the phone is perfectly legal and once it’s been done, it will allow you to benefit from being able to choose which network you use. If you are looking at selling your phone then making sure it’s unlocked first can sometimes increase it’s value and also make it easier to sell.

How do I know if my phone is locked or unlocked?
Very simply you can find out by taking out your SIM card and putting in one that’s for another network. If when you switch it on, you get a message that says something along the lines of ‘SIM Card not accepted insert correct SIM card’ or ‘SIM card rejected’ then your phone is locked and you will need to unlock it before that SIM card can be used in it.
The first thing to think about is how old is your phone? If it’s more than a certain age, usually around 1 year old, most networks will unlock it for you for nothing (virgin will normally do this if it’s more than 3 months old). So this is often the best place to start. Phone up the customer service line for the provider you use, and ask them about it. They’ll almost certainly want to know some information like the make and model of the phone, and your phones IMEI number. This is a 15 digit code that is on the inside of the phone normally underneath the battery, so it’s best to do this before you phone them up so that you have the information ready to give to them if they ask.
What if my phone is newer or the network says they won’t unlock it for free?
Well you can opt to pay for it to be unlocked – lots of phone shops will provide this service, as will some websites. Or, you can try and find the information yourself and unlock it for free. Google is a good obvious place to start for this and by putting in the right information you will probably find what you are looking for. You need to put in the brand, and then free unlocking and you’ll find hundreds of links will appear. So for a Nokia phone I might put in ‘Nokia free unlocking’. Avoid any sites that want you to phone a premium number, all they’re doing is charging you but in a different way. In the search results, look for something that says DCT4 Calculator, or you could try seaching for free DCT4 calculator. This is a piece of software which works out what your unlock code is. The software is in the public domain and is free to use. Most modern phones can be unlocked using this calculator. You will need your IMEI number that you’ve already found, and a network operator code which is often listed on the website where the DCT4 software is. Basically then it’s a matter of following the instructions on the site and putting in the details of the phone, the IMEI number, the network operator code etc. and then you’ll be provided with a series of codes one of which will unlock your phone.
There are a few phones which won’t be unlockable in this way, and if yours turns out to be one of them, then you will need to find out from your provider how and when you will be able to get it unlocked and then decide what to do from there. Hopefully however, most people will be able to solve their problems with this guide.