Go Sim offers cheap international SIM cards that can save you up to 90% when calling from over 195 countries around the world and your incoming calls are free so long as youre in a major tourist destination like Australia Monaco Sweden or the United States and with our special promotional codes you can save even more money so you can talk longer to the loved ones you left behind. Its easy to add airtime to the card that you use you just log on to their website and in the same area where you set up your card and you add airtime and credit! You can also use their website to send a free SMS (text message) to anyone on their Global SIM network so its free for you and for them.