help from mobile phone gurus

[Alex]

Hi,

To cut a long story short. Father-in-law won an Iphone5 in a competition. He doesn't want it. We sold it. It came unlocked for any sim card.

Would putting a sim card in it lock the phone again? Or once it has been unlocked that's it unlocked for good?

Thanks.

Alex

[scotsoft]

Once it has been unlocked it is unlocked for good Alex 

cheers John.

[Alex]

Thanks John, much appreciated.

Alex