T-Mobile today announced it will begin offering Data Stash, letting customers rollover their unused data from month to month.

Starting in January 2015, T-Mobile will rollover data for Simple Choice customers who buy 3GB or more for smartphones and 1GB or more for tablets. To kick off the deal, T-Mobile is putting 10GB of free LTE data into customers’ Data Stash.

T-Mobile’s latest Uncarrier move comes less than a month after Tier 2 carrier C Spire Wireless announced a similar service offering to rollover up to 6GB of LTE data from month to month.

Under T-Mobile’s program, unused data can be stored for up to one year. The carrier doesn’t place a limit on how much data can be stored in the Data Stash.

Once T-Mobile subscribers exceed their high-speed data limit, they’ll automatically start dipping into the Stash.

T-Mobile’s 200MB free for life program won’t be included in the rolled over data and data won’t begin rolling over until the initial free 10GB of LTE has been used up.