International sim cards are sim cards that aren't tied to any particular country and will give you data, calls and texts to use in over 100 different countries around the world. It comes with uk and american phone numbers (2 numbers total). Sim cards available in the usa. When you switch countries, the international sim will generate a new, local number for your phone, allowing you to text, call, and use data over a local network. International sim cards are typically more expensive than local sim cards, but you’re paying for the convenience of having them sent to you before your trip so that they are ready to go before you even arrive meaning that you’ll be able to use.