Unlock your O2 iPhone for free from today

O2 iPhones can be unlocked from today -- totally free if you're on contract. The ability to put different SIM cards into your iPhone comes just in time for the iPhone's arrival on Vodafone and Orange.

Pay monthly customers can unlock their handsets at any time, completely gratis. Once unlocked, you can stick any SIM card in your iPhone and off you go. Sadly, you'll have to continue to pay O2 for the duration of your contract.

Pay as you go customers have to pay £14.70 to unlock. If your PAYG iPhone is less than a year old, you can unlock and the fee will be deducted from your airtime balance.

To unlock your iPhone, fill in O2's standard unlocking form. You'll receive a text confirmation of your request. Unlocking will take up to 14 days. When you have a non-O2 SIM in the iPhone, plug it into iTunes and iTunes will confirm the iPhone has been unlocked.

This is good news, even for those who are happy with their current situation. The ability to swap SIMs means each Wednesday you could stick a cheap Orange PAYG SIM in your iPhone and hey presto: instant free cinema ticket courtesy of Orange Wednesday. Or if you're travelling overseas, you could stick in an overseas SIM card and dodge those pesky inflated call rates.

Changing SIMs does mean you'll need new access point name (APN) settings to allow you to surf and send messages. You can see these in your iPhone's Settings menu: tap General, then Network, then Cellular Data Network. APN settings can be manually edited here, or requested from your new provider, which should be able to simply text them to your phone.

Phone companies are traditionally unforthcoming about letting you exit from their clutches, so we'll be interested to see how easy this process turns out to be. We've already put in our request and we'll let you know how we get on. If you're unlocking your phone, keep us posted on your progress.