Looks like there is a slot that could be used for a sim card - I don't want to take it apart for fear I'll break the phone. As I said in the description - it works as it is so if it needs a sim card to work then there is a sim card in the phone already. This was given to me by a DEAR FRIEND who could not figure out how to work it. I got as far as charging it up, turning it on and making a few calls with it.