Is AS Billed?

AS is free, but you need to pay for pay-per-use instances in your AS groups. For pricing details, see Billing. EIPs used by the instances are also billed. When the capacity of an AS group is reduced, the automatically created instances will be removed from the AS group and deleted. After they are deleted, they no longer generate any fees. Instances manually added, however, are only removed from the AS group. They are not deleted, so they are still billed. If you do not need these instances, unsubscribe from them on the ECS console.

For example, if two instances are added by the system to an AS group but are removed one hour later, you will be billed for that one hour of use.