I was recently in SXM with an unlocked 3G phone which I thought would work with a Chippie SIM card. The Tech Hub phone store at Carrefore supermarket next to Mark's Place said that although a minimum of 3G was required, my phone was designed for US use only. I ended up buying their cheapest phone with SIM card for $70., which included about 30 minutes of time. The SIM card expires in 30 days and can only be topped up by you (or someone on your behalf with your number) while on island. A replacement SIM card alone was said to cost $25. Hope this was helpful.