disco stu, there will always be a charge no matter who you use. But if u can get a sim card and put in your unlocked global cell phone it will be way cheaper than using your cell phone's rates. In order to buy a sim card from digicel or Lime you have to first have an unlocked global phone from your cell phone carrier. ATT is the best one Verizon has minimal cell phones that will allow you to do this. Tell me what carrier you have and then you can be helped better.