Originally Posted by
LIH Prem
On their sim selection page it wasn't obvious to me which to pick for an unlocked iphone.
One the one hand it is unlocked, but on the other hand you want to pick a SIM that works with AT&T/3G + iphone so I think you have to pick AT&T locked.
-David
They allow you to choose. If your phone is locked to ATT, you choose a ATT SIM, same with TMO. If your phone is unlocked, you can select the SIM that offers the best coverage or performance (ie TMO 4G) for your location or where you travel most. If you're not sure, you select an unlocked SIM and they use your zip code to figure out which network (ATT or TMO) gives you the best local coverage.
For example, I have an (now) unlocked iPhone 3GS - only ATT gives me 3G speed with that phone, so I chose the ATT SIM. If I sell the phone and get a Google Nexus/Samsung Android, then I can ask for the TMO SIM and swap, while keeping the same number, and use the TMO network and 4G.