SIM cards are specialized microchips that store your phone’s number, address book and even text messages. The use of SIM cards simplifies transferring data from one phone to another. The AT&T GoPhone plan offers cellular service without having to perform a credit check or having to sign a long-term service contract. If you are switching to a new SIM card, but wish to keep your old GoPhone SIM card number, you may do so by porting the number. Tips Warnings Writer Bio
