Nano SIM Cards Now Available at T-Mobile Stores, iPhone 5 Support
T-Mobile corporate stores are now getting iPhone 5 compatible Nano SIM Cards available for activation. The SKU on the version shown below is ZZZ260R038, in case you need to look it up. I’m trying to get ahold of an unlocked iPhone to test out how the 3G service is with T-Mobile in my area, which has supposedly been re-farmed in my area.
Several users have already purchased the Nano SIM Cards and are already testing them out on the Verizon iPhone 5, which is shipping unlocked to accept GSM SIM cards.
https://www.youtube.com/watch?v=zvtyYRRxpjw
Source:
http://www.engadget.com/2012/10/06/nano-sim-available-t-mobile-iphone-5/