T-Mobile prepaid cards or, refill cards as they are more commonly known, let customers pay for minutes and data for T-Mobile prepaid phone. In the United States, T-Mobile refill cards can be purchased in denominations of $10, $30, $50 and $100.
A $10 T-Mobile prepaid card purchases 100 minutes for the company's prepaid mobile plan, as of July 2015. A $30 card purchases 300 minutes, a $50 card purchases 500 minutes and a $100 dollar card gives customers 1,000 minutes to credit a T-Mobile prepaid plan. While the cards are primarily used for the phone provider's prepaid plans, they can also be used towards other T-Mobile accounts.