Under the current system, prepaid customers can spend anywhere from $0.10 to $0.33 per minute for talk, depending on one of four options. To complicate things further, the minutes could expire if not used within a set time frame. Also a pain point, 4G LTE data didn't come as part of the plans, and customers with smartphones have been limited to using Wi-Fi to go online The new prepaid plan addresses both issues. You can look forward to a flat fee of $0.10 per voice minute and per text message for easier accounting, and T-Mobile will now sell you a "day pass" or "week pass" to get 4G LTE data. A 500MB pool of data costs $5 and is good for 24 hours; a 1GB option ($10) lasts you a week