I have seen lots of threads about the family plans and such, but I may be in a unique situation: Currently my family has a family plan with ATT but it is being paid through my dads small business. So instead of a Social Security number they asked for his Tax ID number when signing up So we have 3 lines, I have the blackjack with the 40$ data plan, my dad has another phone without data and my mom has one without data. When I get the iphone will we be paying less than the current extra 40$ for my data plan? And will I be able to do this with the iTunes iPhone activation at home? Given we are using a tax id number for the account and I have a current data plan but in a sense would be downgrading or altering it? Any help would be great!!