A method and system for managing subscriber payments is disclosed. When a subscriber account reaches a threshold state, the subscriber may be directed to a payment platform that requests the subscriber to make a payment in order to continue using telecom service. As described, a billing system determines the subscriber's rate of usage of telecom service so far in a current billing period and then applies the determined rate of usage to predict a quantity of telecom service that the subscriber will use in the remainder of the billing period. The billing system then computes an overage charge for at least a portion of the predicted quantity of telecom service and conveys at least that overage charge to the payment platform. The payment platform then requests the subscriber to pay at least the computed overage charge, preferably as a condition to the subscriber using further telecom service.