If you are on O2 PAYG
A use for all the O2 SIMS everyone seems to grab everytime they come up You can get upto £50
Step 1 - Get new sim card.
Step 2 - Send an SMS from existing handset with existing SIM Card to 865555 with the Mobile Phone Number that came with your new SIM Card (e.g. 07999 123 456) as the message.
Step 3 - O2 will send back a message confirming your upgrade and your free calltime credit amount.
Step 4 - The calltime credit will be applied to your calltime balance in 14 days. The new SIM card and new mobile phone number will be disconnected.
Step 5 - You can now use your new handset whilst retaining your existing number, calltime balance, Bolt Ons and any numbers stored on your SIM card.
Step 6 - Once calltime credit has been applied, bin the new SIM Card