(CNN) - T-Mobile is bringing back its unlimited data plan on September 5, after a year's hiatus -- and this time it's with 4-G coverage. But before you get too excited about it, there's one big rule you need to know about.
Customers are not allowed to tether their smartphone to their computer, or use it as a mobile hotspot.
T-Mobile's new plan will cost between 69-dollars-and-99 cents and 89.99 a month.
With the latest package, T-Mobile joins Sprint as the only large national carriers to offer unlimited data plans.