Activating new 4s with a working foreign SIM?

[boomasta]

Hi Lads and Gents,

this just dawned on me so please bear with me... i have searched the forum but could not find a definitive answer.

I have an unopened iPhone 4S.. and I was wondering if i pull out the original ATT sim and put in my foreign (working) sim, what would happen? Would I not be able to activate? or perhaps worse, lock my phone to the foreign carrier?

Any input is appreciated..

 

[miles01110]

It wouldn't work. AT&T iPhones can only be used with AT&T SIM cards.