CDMA phones had no SIM cards and needed to be authenticated by the service provider, which made unlocking a phone impossible. You could also put a different SIM card in your unlocked phone, and your phone would then work with whatever phone number and account was linked to that card. You could take the SIM card out, put it into another phone, and if someone called your number, the new phone would ring. It contains all your contacts and settings, and it's linked to your account. A SIM card is a small card that's inserted into the phone. Click the '.' button and select Manage Household. Now, select the Home of the Sim you'd like to move out. To do this, press Esc to bring up the main menu and select 'Manage Worlds'. What's the difference? GSM phones used subscriber identity module (SIM) cards. You may need to do this with a Teen who has grown up, or when Sims have broken up and no longer want to live together. However, if your phone operated on a GSM network, then it might be unlockable. If you had a CDMA phone, then your phone was unlockable. There used to be two cellphone technologies that were used by the majority of the world's mobile phone service providers: Global System for Mobile communication ( GSM) and Code Division Multiple Access (CDMA).
Some phones even have space for two SIM cards, useful if you do a lot of international travel. You can switch out the card to use another cellphone company.
