Yes it does come with a SIM card. The SIM card is for their network. You have to activate the phone on their network first (which has an activation fee of course), and then you can change it over to another carrier if you'd like. I've been trying to do it for two days but their network has been down. I am going to use this phone with Verizon (hopefully soon). Not sure if I will have to swap out the SIM card for my Verizon one or not when I do get to that step - hopefully today. Customer service has been real friendly and I haven't waited on hold long at all, unlike a lot of companies.