application monytizing

[nyctophilia]

Hi, There

I am currently developing and application that will pay your prepaid bills by utilizing the phone (bear in mind its a local application) my question is I want it to be all free except when the person whats to recharge his account I want to have a cost of 5% percent of what the person is putting in his account and that five percent would be my take from providing the service where I am stuck at is how can i do this or what service provider I need to contact to do this.

any help would be greatly appreciated

Thanks