Prepaid customers on T-Mobile no longer have to worry about losing unused data. Starting March 22 they will benefit from the carrier’s Data Stash program, the carrier announced Monday. Prepaid customers will be allowed to rollover unused data into a storage bucket, to be used for up to one year.

With Data Stash, qualified prepaid subscribers under T-Mobile’s Simple Choice plan will get a Starter Stash with up to 10GB of 4G LTE data, which they can tap into if they go over their data capacity during a service period. Once that data is used, customers can start rolling over unused data into their unused data stash. That data can be used for up to one year after it’s rolled over.

T-Mobile originally established the Data Stash program for subscription customers in December. The carrier says it has seen a positive response to Data Stash, with 27 percent of customers having utilized data in their stash.

However, prepaid users should keep in mind that they can only utilize Data Stash if they have a standard prepaid plan, such as the unlimited talk and text and 1GB of 4G data. Users that have unconventional prepaid plans, like the 100 minutes of talk and 5GB of data plan, are not eligible for Data Stash.

T-Mobile is planning another big announcement for March 18, where it will host a press event in New York. The carrier sent out invites last week with a teaser that says “This one’s a real piece of work.”

The carrier also set up a new promotion, in which it is offering unlimited 4G LTE data to a small set of subscribers --starting April 1 to the end of the year – at no extra charge. Selected subscribers will receive a text message alerting them to the promotion.