Want the answers to questions about the iPhone? You'll find questions and answers here.
Make iphone4s straight talk compatible
Is that a question or command?
Contact the carrier it is currently locked to.
Inquire about their unlocking policy.
See if you qualify.
Buy a StraightTalk iPhone. They are a supported CDMA carrier, but you have to have a phone made for their network. Neither StraightTalk nor Apple support using an unlocked GSM phone on StraightTalk. It can be made to work, but you will not get all the features.