The next step is unlocking the phone, and for this process to be successful, you will have to contact the new carrier and inform them that you want to switch to a new SIM card.
On a piece of paper, you will copy it down because it is what you are going to use to unlock your phone.
Straight talk phones for example come locked, so once you purchase the device, and use it for 12 months with the pay as you go service, then the telecommunications giant will unlock the phone, below is the request process. Each provider has laid out terms and conditions that should be observed before you can get your phone unlocked, and even when the time comes to unlock the phone, users still have to request their service providers to unlock the phone.
Locked phones can only work with the provider’s network, but you can have it unlocked to use with other networks.