if i pay 30 bucks for 3g from t mobile can i have more than one phone on it or do i

[Kelvin]

have to pay another 30$? Well my brother is changing his phone since he is going to get a discount and the phone of his choice is htc hd2 and they told him that he needs to pay internet wich im guesing is the 3g crap...well he is paying 30 bucks extra a month. My question is if i change my phone to the my touch slide 3g will my brother have to pay another 30 bucks of internet or does it cover both phones? thnx in advance guys