In most cases when a cellular phone is purchased from a service provider,
it is often sim locked to that provider such that only sim cards from that particular service provider will work.
Cell phone unlocking removes this carrier lock, It enables you to use your phone with any sim card,
regardless which provider you bought it from.
No one provides free unlock code. If anyone provides some codes and that codes dont work properly and then the phone may permanently locked. Codes generate from server based on the IMEI code so nobody can give the unlock code free of charge .
There can be many ways to get unlock codes. If the contract period of the mobile phone gets complete one can ask their cellular operator for the unlock code. But, they do make it very difficult for you to get the code.
Its better way to visit Unlockgenie and can see different options there to get unlock code for a price. Here we can Choose any appropriate price for different handset models.