When I had my old smartphone, I called att and told them I'd be visiting my sister in London, and that I'd want to use prepaid SIM cards, as it would be cheaper than international rates. They had no problem unlocking it (galaxy s).
Sent from my TARDIS
Any fool can use a computer. Many do. Thank you to all the fools out there: you're my job security! (^.^)
"Android is like MacGyver: a little rough around the edges, but given the right tools, it can do anything!"
Samsung Galaxy S4 SGH-i337 running SHOStock-i
Asus Transformer TF700T running CROMBI-KK
Amazon Fire TV: rooted, with FiredTV launcher and XBMC.