Springing for the One Plus plan rather than the regular package gets customers unlimited HD video play and mobile hotspot access -- both of which are limited with the basic plan. One Plus also comes with unlimited Gogo inflight WiFi and faster international data speeds.

T-Mobile has tweaked its unlimited data service a few times in order to stay competitive with rivals like Verizon and AT&T. After Verizon debuted its new unlimited plan earlier this year, T-Mobile moved its One Plus-exclusive HD video streaming and LTE hotspot tethering back to its basic plan, but that offer was short-lived. Similarly, when AT&T announced it was adding 10GB of tethering data to its unlimited plan, T-Mobile hit back with a buy two lines get one free promo.

The new price point still keeps T-Mobile fairly competitive. It's now on par with Verizon's single line cost and AT&T's is a little pricier at $90 per month. Sprint's plan currently starts at $50 per month. However, Verizon's, AT&T's and Sprint's monthly prices don't include added taxes or fees while T-Mobile's does. T-Mobile customers already subscribed to the One Plus unlimited plan will still only have to pay $5 for the add-on; the higher price is for new customers only.