lukedrever1 If it was bought from giffgaff it should have come unlocked, otherwise
The network it is locked to can unlock it. Check to find companies UNLOCK policies
Many will send you the unlock code for free using their online form. I unlocked one for free on PAYG from VODAFONE.
To find your networks unlocking policy GOOGLE the network name followed by the word UNLOCK
You will need your IMEI number which will be on the original box, or under the battery if it can be removed
You can find your IMEI in the following ways: by entering *#06# on your phone's call screen.