evidence: When you enable FaceTime it sends an SMS to an Apple server in the UK to activate the service. Normally carriers that support the iPhone do not charge for this SMS. However, your carrier may not participate, in which case using FaceTime can get to be expensive, because it periodically updates that server with a new SMS. FaceTime is a free service from Apple. It requires an internet data connection, either wifi or cellular. If the data connection is free, there are no charges at all. If a carrier or wifi provider charges you to use their data connection, then charges will apply (to the internet connection provider, not to Apple). The same thing applies for Apple's free iMessage service. [...] This has nothing to do with whether FaceTime uses data over cellular or WiFi. This refers to the activation process when you enable FaceTime. The message means that enabling FaceTime will involve an SMS - actually an International SMS - to activate the service in Apple's servers, and this specific carrier may charge for that International SMS. As it's international, it will be expensive - probably 50 cents per message or more. And this charge will appear every few days as FaceTime reactivates with Apple's servers.