Abstract: A method and system for dynamically optimizing the amount of an automatic refill of a shared virtual postage meter is disclosed. A desired time between refills is predetermined based on the capacity of the system to perform refills, the time required to process a refill, and the impact of performing a refill on the overall performance of the system. A refill amount candidate is then determined based on the predetermined desired time between refills, the elapsed time since the last refill and the amount of the last refill. The determined refill amount candidate is then further validated to insure that it falls within a range of a predetermined minimum and maximum refill amounts. Once validated, the refill amount candidate is the optimal refill amount, and the shared virtual postage meter is refilled accordingly.