Purchasing iPhone question

AgaBoogaBoo

Lifer
Feb 16, 2003
26,108
5
81
I'm on a family plan through AT&T, and am going to purchase an iPhone.

If I get two new phones for people on the plan and signing a 2 year contract, and purchase the iPhone at the same time, when I come home to active my iPhone through iTunes, will that make it 4 years or will it keep it to 2 years from the activation?