> How APY works and what it means for you: As a T-Mobile MONEY customer you earn 4.00% annual percentage yield (APY) on balances up to and including $3,000 in your Checking Account per month when: 1) you are enrolled in a qualifying T-Mobile postpaid wireless plan; 2) you have registered for perks with your T-Mobile ID; and 3) at least $200 in qualifying deposits have posted to your Checking Account before the last business day of the month.

So it's a neat little discount on your T-Mobile bill.