How do I unlock my mobile phone?

How do I unlock a phone so I can use my current SIM card in it and is it legal?

Andrew Lim
2 min read

I want to buy a new music phone but it's a T-Mobile pay-as-you-go handset and I'm currently on an O2 contract. I still have a few months left on the contract but I really want to change my phone.

Is there anyway I can unlock this phone to use with my O2 SIM card and is it legal?


Hi Beth,

The main reason why mobile phone companies lock phones to their network is to try to stop you from buying a model on the the cheap then immediately switching to a rival.

The networks say they are entitled to do this because they subsidise the cost of the phone when you sign up with them.

Fortunately, it is possible to unlock a phone and put your O2 SIM card in it and it's completely legal.

Some networks will provide the unlocking code for a small charge, so it's worth trying them first. Alternatively, you can use an unlocking service in a high street shop, online or over the phone.

It costs about £5 and you will need to provide your phone number and IMEI number that you can find out by typing *#06# on your phone. Be warned, though -- you need to be careful who you give your IMEI code to -- it enables people to clone your phone and run up a large bill on your account.

Make sure you use a company that you trust and never give out your IMEI number without knowing what it's being used for.