T-Mobile's prepaid service may not come with a free phone, but it does offer tremendous flexibility. You're not locked into a two-year contract and you pay only for the minutes you use--a great option if you don't expect to spend hours on the phone every month. The downside is, of course, that you need to keep an eye on your account balance to avoid running out of talk time. Fortunately, checking your credit directly from your phone is quick and easy.
Type "#464#" (in letters, "#MIN#") into your T-Mobile prepaid phone. If your phone won't let you do this, or you don't have access to your phone, skip to Step 3.
Press the "Send" key (the key you press to make a phone call). You will receive a message in a few seconds detailing the number of minutes remaining on your account.
Open your computer's Web browser if you don't have access to your phone. Go to My.t-mobile.com and log in to your online account. Your available minutes will appear on the first screen after you log in.
Requesting your balance is free and you can access it any time of day or night, according to T-Mobile's website. This process works for non-prepaid phone users as well. However, they will receive a message detailing how many minutes they have used, rather than how many minutes remain.