T-Mobile has added the iPhone 5 to its site for pre-orders. The T-Mobile iPhone 5, which will have support for HD Voice, can be bought for a $100 down payment, with a corresponding $20 for 24 months payment plan. It can also be purchased in full for $580. The T-Mobile iPhone 5 is set to launch April 12. An option to purchase a T-Mobile iPhone 5 is not currently available in Apple’s online store, where AT&T, Verizon, and Sprint are still the only carrier options. Starting April 12th, Apple retail shops as well as Apple’s online store will begin selling the new Advanced Wireless Services-enabled A1428 model of the iPhone 5, as noted by Engadget.