As both T-Mobile and AT&T have recently introduced the ability to carry over unused data we understand it can be confusing to tell them apart. But, take a close look at the two plans and you’ll see that one is considerably better for users in the long run. T-Mobile, who was first out of the gate with its Data Stash, has the edge over AT&T who followed with Rollover Data.

Here’s a breakdown of how the two plans stack up against each other and why we think T-Mobile is the clear choice thus far.


T-Mobile Data Stash comes with Simple Choice subscribers that have at least 3GB or more per month on a smartphone. Indeed, it works for tablets as well, provided the customer has at least 1GB of data or more per month. As of today this allows for the 3GB ($50/month) and 5GB ($60/month) customer to carry over unused data. Data Stash is available today.

AT&T’s Rollover Data works on any Mobile Share Value Plan, meaning anything from 300MB on up can qualify. Note that Rollover Data begins effective January 25, 2015.

Finer details

T-Mobile gives every eligible customer 10GB of free data to be used however they see fit. Need 1GB in March? Perhaps you’re 3GB over in May. Whatever, you have 10GB to play with in the event of overages or emergencies.

Note, however, that T-Mobile’s Data Stash doesn’t begin to roll over unused data until the initial 10GB bucket is used up. But, that’s not bad. Until you go through that first free allotted data pool, you’re really not dipping into anything outside of the monthly norm anyhow.

For the sake of comparing the two plans against each other we’ll work with a customer that gets 3GB of data per month.

Let’s say that you only use 2GB of the 3GB bucket after the first month (January). Both plans let the subscriber bank the extra 1GB of data. AT&T’s, however, rolls into the very next month (February), allowing for 4GB of data. Should you only need another 2GB of data in February you would not be looking at 2GB of accrued Rollover Data plus the 3GB bucket. Sadly, AT&T only lets you carry over that data for one billing period.

For T-Mobile, you could roll 1GB (January) plus another 1GB (February) into March for a combined 5GB in March. In fact, you can roll over as much data as you’d like for up to 12 months. After one year that first 1GB would fall off and so forth in the following month.

Sharing data

Assume, for a moment that you’re in a shared plan that allows for 20GB of data across multiple lines. A group on AT&T that only uses 18GB in January would get 2GB to carry over to February. It doesn’t matter how you use up the extra data but you’ll lose it if you don’t by the end of the month.

For T-Mobile customers, each line in a family plan with at least 3GB of data is eligible for Data Stash. Along those lines, each person can stash as much data as they want as an individual for up to 12 months.


At first blush it’s easy to call T-Mobile the winner here. Given the free bucket of data to get started, no overage fees, and long term banking, it’s the way we’d go if given the choice. Your personal results, though, may vary. Things to consider include coverage, data speeds, handset selection, rate plans, and more. Do you already have smartphones? How many of you will be using the account?

Regardless of which way you go in early 2015 you’re going to end up benefiting. This is the sort of thing we’d like to see happen across all major wireless providers.

T-Mobile Data StashAT&T Rollover Data

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