T-Mobile upgrades its unlimited plan again to one-up AT&T

New and existing customers with two lines can now get a third for free.


T-Mobile added HD video streaming and 10GB of LTE hotspot tethering to its unlimited One plan earlier this month, possibly as a response to Verizon's new unlimited data plan. Yes, the mobile carrier wars have been intense lately, and they're getting even hotter. Just hours after AT&T announced it was also adding 10GB of tethering data to its unlimited plan, T-Mobile fired back with another tweak to its One plan. Now, new and existing customers with two lines can get a third for free.

Starting March 1st, customers will be able to snag three lines for $100 (with fees and taxes included) on a One, Simple Choice or Simple Choice No Credit plan. And don't worry, if you've already got three or more lines, you can tack on another for free, according to the @TMobileHelp Twitter account. The promo doesn't have an end date yet, but customers who get in on it now will be able to keep their free line for as long as they're on an eligible T-Mobile plan.

So now, we wait and see how the other carriers will respond. The marketplace is super competitive right now, so consumers really stand to benefit from whatever happens next.