The only problem you may have with your device is that you purchased it from your service provider to save money. Now you stuck with a Galaxy S8 that you need to unlock SIM. You need the Master Subsidy Lock code to allow a CDMA device to be reprogrammed (that my understanding), recognize that the phone is only working on other CDMA networks. Unlocked 4g Phones Uk. However, there is a wide range of opportunities to provide you with this service and although none of them are illegal, you really need to review them to ensure that you actually get what you need. Thanks so much. This method works for me. Have a nice day with my Samsung Galaxy s 4g is locked where I got a Gmail username and password must be entered but I do not have it, please help me. In general, this means that your bills must be paid on time, your account is older than 60-90 days, and the phone you are trying to unlock can not be a payment plan.