International calls are expensive, and you don't want to see dollars running away on calls you didn't make or didn't intend to make. You might make international calls accidentally, or your toddler might call one of your international contacts during their playtime with dad's phone, or else you might suspect other people (friends, relatives, workers, etc.) of making international calls without you knowing.
International blocking allows you to block and unblock international calls from your phone line. Of course, incoming international calls will be allowed, as they cost nothing for the receiver. Setting it on or off should be done via your online account management system, so that it is not that easy for your suspects to set it on again.
