Thinking of getting a sim only deal for my son for an iPhone 4s and want to ensure he doesn't go over the data allowance within the package. Since there is no app to do this, does virginmedia either cap the usage to the package limit or have the ability to do this rather than being charged a potential fortune. A simple text message to my sons phone will not enough.
For Virgin's capped data plans, you will incur a charge whenever your son goes over that allowance. Currently, it's £1 per 100MB (or part) per day.
For the "unlimited" plans, the fair use amount is 3½ GB - if your son exceeds that amount, his speed will be dropped to 2G speeds for the remainder of the calendar month. (i.e. not until next refresh and not for 30 days like everything else. Low speeds will be in place until the first of the next month).