This article will help you to get the PUK code for your locked SIM card and reset your PIN number to make your mobile phone work again. SingTel, M1 (previously Mobileone) and Starhub are the leading mobile network providers in Singapore. The SIM cards provided by these networks are equipped with a PIN number to ensure security of the customers. By default the PIN number for all these mobile network SIM cards will be 1234 If you enter the PIN code wrongly for three times, then the phone will be locked and ask for PUK code. If you enter PUK code wrongly for 10 times, then the SIM will be permanently blocked and you have to buy a new SIM . So, In order to retrieve your PUK code and reset the PIN number , follow the procedure provided below for your network . >>SingTel In a piece of paper, note down your SIM number printed on the SIM card. If you are calling from another SIngTel mobile, then call 1688 and choose the option to unlock PUK or speak