How do you switch iphone info to another phone?

I am planning on buying an iPhone 3G on July 11th and i am wondering that since my mom has already established a family plan and can get upgraded whenever she feels like it now (None of the other phones on the plan will be an iPhone though.) Will i still be able to add the iPhone as an add on or will I still have to get another plan?



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It'll cost you an extra $30 a month for the internet/iPhone fees, but you shouldn't have any trouble adding it to the plan. You might want to hold off for another month or two past July though, cause the next iPhone model should be coming out sometime around then (in the summer).