Do you need to unlock your mobile phone before you can buy a prepaid card in Thailand?
I 'm the a user of phone T-Mobile and will go to Thailand for some months. When I 'm in Bangkok, I want to buy a card paid in advance of the phone. Anyone knows if you that you have to unlock your mobile phone before you can buy a card paid in advance in Thailand? If your phone is unlocked, and then when you came back in the UK, there is the problem with your current network?