AT&T's unlimited data plan costs $100 a month for a single line, the most expensive of any unlimited option. Sprint's plan starts at $60 a month, which the carrier is currently discounting to $50; T-Mobile's and Verizon's unlimited plans cost $70 and $80 a month, respectively.
Adding additional lines costs $40 each, but AT&T is waiving the cost of the fourth line. That means a family of four pays $180.
But wait — there's less. AT&T doesn't offer hotspot data with its unlimited plan. The three other major carriers each provide 10GB of LTE hotspot data, though that's a recent change for Sprint and T-Mobile, who tweaked their plans this week to match what Verizon offers.
Credit: jorome/Shutterstock.com On the bright side, you'll be able to stream HD video on AT&T's unlimited plan. On the confusion side, AT&T's Stream Saver feature — which throttles video resolution — is turned on by default, and you'll need to switch it off to enjoy that HD streaming.
Eagle-eyed plan watchers may recognize AT&T's new unlimited offering as the exact same plan it made available to DirecTV and U-Verse subscribers. Until now, to get unlimited data from AT&T, you had to subscribe to one of those two TV services. That requirement is gone now, but given the cost of AT&T's plan and the lack of hotspot data, it's fair to wonder just how many people will take advantage of the offer.