A provider network may implement resource credit pools to replenish resource credit balances for virtual compute instances. A resource credit pool may be maintained that makes resource credits available to virtual compute instances authorized to obtain resource credits from the resource credit pool. Resource credits from the resource credit pool may be applicable to increase utilization of physical computer resource for a virtual compute instance. In response to a resource credit request for an authorized virtual compute instance, a number of resource credits to add to an individual resource credit balance for the authorized virtual compute instance may be determined. A response may be sent indicating the number of resource credits to add to the individual resource credit balance and the resource credit pool may be updated to remove the number of resource credits from the resource credit pool.