Whale Cloud Real-Time Billing (RTB) is a next-generation convergent billing system which adopts a distributed cloud-native architecture. The new concept of real-time billing significantly reduces operation expense and brings truly real-time experience to customers. With a series of visualized, automatic tools, CSPs can build a continuous improvement of billing processes which ensures the billing accuracy. The powerful account receivable management supports various financial transactions and the administrators can define the approval process for key financial transaction such as adjustment and refund. All requests can be monitored and audited on GUI to avoid revenue leakage. The flow driven collection & dunning process allows CSPs to define personalized processes based on diversified factors such as customer segment, customer grade and service type, which helps CSPs improve the collection success rate and reduce the O&M cost.