is a flex-pay plan with t-mobile separate from the monthly t-mobile plan?

[moniiee]

i have a T-Mobile (NYSE: DT) phone and i only have enough money to pay for the flex account which would be like $10 or if i want to $15 using a pre-paid card. but will the money be used on my monthly account ???because my amount due for that is $35 and i dont have enough.

[sahil]

then its ok go off sleep