Apple's iPhone 5 debuts on T-Mobile April 12 with $99 upfront payment plan

The announcement was made Tuesday by T-Mobile as part of the company's "Uncarrier" branding, which seeks to differentiate the carrier from competing providers like AT&T, Verizon and Sprint — all of which already carry the iPhone.

In standing out from the others, T-Mobile is offering a 16-gigabyte iPhone 5 for $99 up front, with 20 additional monthly payments of $20. With an April 12 sale date in T-Mobile's retail stores, preorders will begin April 5.

Joining the iPhone 5 will be the remainder of Apple's current smartphone lineup: the iPhone 4S and the iPhone 4. As with other carriers, only the iPhone 5 will be compatible with T-Mobile's new 4G LTE high-speed data network.

T-Mobile officially announced its new LTE network at Tuesday's event as well, available in a total of seven U.S. markets: Kansas City, Kan., Houston, Tex., Las Vegas, Nev., Phoenix, Ariz., San Jose, Calif., and Washington D.C.

T-Mobile's new data plans include 500 megabytes of high-speed online data and unlimited calls and texts for $50. For an extra $10 per month, users get 2.5 gigabytes of high-speed data, while unlimited 4G access runs $70 per month. In addition, users are simply throttled, not penalized, when they go over their data cap.

Bringing Apple's iPhone to T-Mobile with full support has been no small task. While the carrier counts some two million iPhone customers among its base — with about 100,000 added per month — T-Mobile's reliance on the 1700MHz frequency for its 3G HSPA+ network proved an obstacle for T-Mobile with regard to Apple's bestselling smartphone.

The 1700MHz frequency, branded as 4G but not LTE, is unique to T-Mobile among carriers, and allows iPhone users only very slow 2G connectivity. Given T-Mobile's relatively small customer base, Apple never moved to support T-Mobile's standard. Instead, T-Mobile has been working to switch much of its network to 1900MHz in order to allow iPhone connectivity. The company will be repurposing its 1700MHz band for 4G LTE.

T-Mobile last year announced a deal with Apple to begin selling Apple products in 2013. Executives from the carrier said in January of this year that customers could expect Apple products on T-Mobile sooner rather than later, floating the possibility of "three to four months" rather than "six to nine."